My recent post on the AOD transmission brought out some unfavorable comments on that particular transmission. The AOD was designed during the time period not known for great transmissions. American manufacturers were concerned with meeting CAFE requirements but at the same time were also trying to minimizes costs. These circumstances were not ideal for the development of all new transmissions and lead to some pretty poor designs.
The TH700-R4 evolved in the the 4L60E (4L65E/4L70E). Like the LS engine, this modern automatic has proven to be a good transmission that is commonly used in powertrain swaps. This photo shows GM’s Connect and Cruise powertrain package which includes this transmission.
Many of the transmissions designed in this era, like Ford’s AOD and GMs TH700-R4, helped increase fuel efficiency but were compromised designs that suffered from under engineered components, poor reliability and poor operation. Fortunately, as time went transmission design was improved, especially with the adoption of electronic control. Some older designs, like the aforementioned AOD and TH700-R4, were modernized in the 1990s and become good transmissions.
A cutaway of GM’s Turbo Hydramatic 350
With that said, the era previous to this from the mid-1960s to the late 1970s produced some of the America’s best transmissions. The majority were 3-speed automatics based on the Simpson gearset that resulted in some basic, but great transmissions that not only operated very well, but were generally very durable. They were so good, that even some European manufactures used them, such as GM TH400 in Ferrari’s, Rolls’ Royce and Jaguar.
Buick’s Dynaflow was one of the more successful non-mainstream transmission designs.
Going further back to the late 1940s to the early 1960s was an era that produced the earliest mainstream automatic transmissions. There was little standardization in design during this time, which lead to a wide variety of designs. There was the game changing Hydramatic, which had four-speeds, but used a fluid coupler instead of the torque converter. Chevrolet had its venerable Powerglide, but also produced the short-lived trouble prone Turboglide. Even Packard and Studebaker got into the game with Packard Ultramatic and the Studebaker (Brog-Warner) Automatic Drive. It was also during this time that the more conventional Chrysler’s Torqueflite A-488 was first released for the 1956 model year. It proved to be winning forward going into the 1960s.
A cutaway of the Ford/GM 10 speed automatic.
Today, much like the early 1980s, fuel economy has become a prevailing factor in transmission design, resulting in much more complex multi-speed transmissions and CVTs. Unlike the early 1980s, the engines today are stronger than ever and the transmissions are correspondingly stronger than ever before. Case in point, Ford and GM’s joint venture on the 10-speed automatic transmission for RWD applications is rated to handle over 600 lbs-ft of torque in its strongest variations. Of course, these new generation transmissions have their own complaints. The large number of speeds has led to shift confusion, erratic shifts and expensive repairs. CVTs seem to be either loved or hated and also have had spotty reliability records.
A failed Torqueflite 727
That leads us to the question of the day. What is your favorite and least favorite automatic transmission? Tell us your choice and share your experiences good or bad.
least favourite transmission: a604, never worked well in my (AA) Saratoga and finally quit after 138k kilometers.
If transaxles count, my least favorite is the GM 4T65E. My wife had two cars (albeit with over 100,000 miles) with that special brand of engineering, and both would shift very, very hard after about a half hour of driving. From what I was able to gather, once the transaxle got some miles on it and began to slip a little between shifts, the computer would jack up the line pressure all the way to 11, with the subsequent filling-rattling shifts. At the same time, the transaxle would constantly whine, I assume because the pump was operating at fire hose capacity (just conjecture).
I partially solved the problem in our ’04 Impala by installing a shift kit. Ironically, by making the transmission shift faster, it kept the computer from noticing enough slip to jack up the line pressure. Anecdotally, this is a problem with many 4T65Es. I live in an area where every old Grand Prix and Impala goes to die, and I can hear one before I see it, because the transmission is whining as it approaches. Similarly, I can always tell when an old S10 Blazer with four wheel drive is approaching because the ball joints are all squeaking, but luckily, those are starting to disappear from the roads by now.
Yes automatic transaxles count too. I am just a little bit RWD biased. If you don’t count my wife’s cars, I have never owned anything but RWD vehicles.
You didn’t tell us your favourite Aaron. Maybe it’s the new Dynaflow?
Ha ha…There’s actually nothing wrong with a Dynaflow other than its propensity to leak. They’re certainly smooth and seemingly robust.
I like any transmission that doesn’t give me trouble! Right now, I have a Ford C-4, a Turbo 350 (it’s a little sluggish on a cold morning, and I’ll eventually have to rebuild it), a GM Super Turbine 300, two Dynaflows, and a Ford Cruise-O-Matic. They’re all pretty good, I’d say.
My wife’s Mustang has a 6R80, and it’s had a slight whine forever. Changing fluid is no fun at all; the “dipstick” is a short plastic thing right next to the catalytic converter, and you have to check the level with the engine running. That was a fun day.
Yeah, that is SO stupid that they don’t provide you with a proper dipstick on these Retro-Stangs… what were they thinking?
(Another reason for the love/hate on this one that I covered below)
I have two favorites. Drove a 2016 Chrysler 300 for a limo service, got it from brand new. The Pentastar 3.6 AWD paired with the 8 speed ZF was flawless. Put over 100,000 miles on it in a year. It never hunted or shifted erratically and would routinely deliver over 30 mpg on the highway. My other favorite would be the Ford 6F50. Have a 2008 Taurus X with 270,000 and a 2012 Lincoln MKX with 220,000. Both AWD, rust is going to take these down before the powertrains give out.
My least favorite would be the AX4N. Had one in a 1999 Continental. Managed to get 173,000 out of it, but after 100k it was problematic. I know that there’s not much love for the Continental, but the Intech 4.6 was a great motor saddled to a lousy transmission.
I love my ’99 Continental, in part because it was exquisitely pristine when purchased, 8 years ago, yet cost me the equivalent of $1100 USD.
It’s the best used car purchase I’ve ever made, partly because few people know anything about them and demand is low accordingly
The transmission has worked flawlessly. I’ve serviced it once. However, I’m aware other people have issues so I drive it relatively conservatively.
I mostly drive manuals so don’t have that much in-depth experience with automatics.
Favorite: Volkswagen’s DSG (I’ve only driven the 6-speed version in the Golf GTI). Such speedy shifts and always in the right gear.
Least favorite: any whiny CVT.
Though hardly my favorite AT, I’ll note that we had a ’77 Bonneville with the infamous THM200 for about 15 years and it performed smoothly and flawlessly.
Of the 5 vehicles we have 4 are manuals, so I’m a late technology adopter when it comes to AT 🙂
Anyway, my favorite would be the GM THM 350, I don’t know anyone who had a bit of trouble with one despite heaps of teenaged abuse and many miles.
Least favorite is the 6 speed auto in our 2015 Caravan. Thank goodness for the extended warranty that paid for a new tranny at 90,000km. It hunts gears on the highway, and in town it upshifts too soon, super annoying in hilly terrain: Going up a hill, transmission shifts util the engine is turning 1500 rpm, not enough torque to accelerate, push gas until it forces a huge whopping downshift and varoom! you rocket away.
I have driven a few rental versions of the van you have (some older, some newer) and know EXACTLY what you are talking about. It didn’t help that my last experience was after I had already spent quite a bit of time living with my Kia, therefore making my Dodge experience even worse.
How hard do you have to run a 727 Torqueflite to blow it apart like that picture above? That could handle a Hemi’s torque, and outside of the most powerful late-stage 455s from GM it didn’t get more powerful than that.
Anyway, my favorite transmission is the THM425 for the simple reason that GM had to innovate to make a transmission work for a longitudinal V8 with front-wheel-drive, and the solution they came up with, the Unified Power Package, worked very well. When GM decided to make something and didn’t cheap it out at the last second their stuff was usually pretty good.
My least favorite was the early-mid 2000s Honda transmissions. I bought my grandfather’s Accord from my mother after he died, it was a well-maintained, low mileage example, and inside of 6 months the transmission failed requiring a replacement that I couldn’t afford at all. Shortly thereafter my mother died and my stepfather spent a year abusing me about how I tried to take advantage of my dying mother to grift her out of money, which wasn’t even remotely true, all because usually reliable Honda built a bad transmission that I came to find was notoriously failure prone.
Wow, since I can’t ID them all, especially from memory, I’ll list each COAL, and that may determine what I had.
1973 LTD w/ the 351: I’ll assume it had the C6. I was a teenager when I owned this car. I never had an issue with it, despite the kind of antics you’d expect from that demographic.
1979 Fairmont Futura w/ the 200 inline 6: I’ll assume it was a C4. Late teen at this time, going into my early twenties. Again, no issues with this one. The 200 was so underpowered though, so the C4 likely saw no stresses.
1983 T-Bird w/ the 3.8L V6: Again, I think it was the C4, as I only had 3 forward gears. No issues in the roughly 152K I put on the car. The engine was a whole nutha story!
1988 T-Bird with the 302. First car with a 4 speed auto, so I’ll assume it was the AOD. I put 236K on that car, and it was still breaking the tires loose when I traded it in. The only trouble I had with it was covered by Vince’s excellent article last week or so ago. That little plastic piece at the top of that rod that connected the fuel injection’s throttle control with the transmission failed. I drove the car very carefully as it was slipping to a transmission shop. The guy asked me if I had 10 bucks. I said yeah and he said hand it to me. He disappeared and came back with this part and snapped it on. He said, that should do it, and followed up by saying, “You would be amazed at how many transmissions I’ve seen fail because of this stupid little $2 part.
1997 (as well as my ex’s 1994) T-Bird w/ 3.8L (& 4.6L, respectively) – I’ll assume these were the AOD as well. Contrary to the indestructible one I had in the ‘88, my T-Bird’s started slipping at exactly 1/2 the mileage of the ‘88 at about 118K, so I traded it in on a slightly used ‘97 GTP. The ex? Her ‘94 started giving her trouble shortly after we split up, and she traded hers for a ‘96 Taurus (no idea which one it had) which also failed similarly a couple of years later. We never did check the little plastic piece, and just got out from under these cars instead.
Side note on the AOD: I agree with what was said in Vince’s article about the 4th gear being too tall (? If I understand that correctly). In the ‘88, I had. To push the button to keep it in 3rd if I needed performance in rush hour. It was similarly like this in the ‘97, but less noticeable of a problem for the 4.6 in the ‘94 ‘Bird…
1997 Grand Prix GTP (supercharged 3800 Series II). Whatever its slush box was, I never had any issues with it.
2007 Mustang w/ the 4.0L V-6. 5 speed AOD. This was the only transmission that ever completed failed on me (at 170K). I loved how smooth it shifted, so instead of dropping a rebuilt one in, I had the original rebuilt. It shifts smoother now than when it was new. I’m nearing 184K, so stay tuned…
Funny thing is about both the AOD and the Mustang’s 5-speed AOD are the shifters. For the T-Birds, it was 1-2-D and the Mustang is 1-2-3-D. In each case, there’s a button that you push to turn the “O/D Off” (as it’s displayed) to keep the car in the penultimate gear. Why is this? Why can’t it have all 5 (or 4) shift positions?
Regarding CVT(s) – I hated the one in my wife’s ‘09 Lancer, but I love the one in my 2016 Turbocharged Civic. The underpowered Lancer felt like the transmission was a rubber band, while the Civic seems to have fake shift points. Once you get used to it, it works pretty well, and can even be driven sportingly.
The CVT in my daughter’s Jazz/Fit has those fake shift points. Think she said it acts like it’s got six speeds. Sometimes she plays with the paddles but usually leaves it alone to do its stuff.
I have had 9 302 AOD cars, mainly panther wagons or town cars. Only 1 trans failed after towing a trailer and having a large leak. 3.27 gears seem to be the best for this trans. Have had 2.73, 3.08, 3.27 and 3.55 gears.
Five other cars, early cougars and fox body, had C4/5 which only one died. My aunt – a major speed demon killed it.
Two old Mach 1s with FMXs. One blew up behind a monster 351c.
As for C6s, two cars and tow trucks. One died trying to get out of a two foot snow bank. My current truck has a C6 with 348,000 miles.
I am biased to the 727s. I am currently running an iron one in a 62 D200. Aluminum one in a 71 D200 with a Gear Vendors overdrive. I rather despise the 10 speed in the Ford Transits. Driveability sucks worse than a kid trying a stick for the first time. Allison AT545 and it’s electronic offspring are crap drivers albeit long lived. From the same people though the MD 3060 is a great one that just works right.
+1 on the 727.
I may be a little off-topic, but I have to comment. I grew up in early 1950’s, and every school kid I knew could tell a Chevy from a Ford by the sound. That distinctive whine of those Chevys carries a lot of nostalgia.
The ’60’s Buick ST300 also used by Olds and Pontiac was a different transmission than the Powerglide but had that that same whine. I only recently learned from this site they were different transmissions.
My all time favorite automatic: Mopar 727 Torqueflite.
Least favorite: Chevy Powerglide. ( Paul’s rejoinder in 3…2…1… 🙂 )
I, as usual, jump to defend Powerglide. It provided a cheap, reliable design for people who didn’t care about 0-60 times. GM kept it around far too long. It should have been replaced circa 1967.
+1 on the iron 727.
Best transmission experience ever. Owned several over the years – all stone cold reliable. First one I owned sold me on the reliability. Has it in a ’58 Plymouth 318. It was an air cooled unit with no transmission lines to the radiator. Despite pulling a very heavy trailer with the Plymouth, never had a problem despite routinely overloading the thing.
Worst transmission experience was with the ZF4HP18 as used in my ’88 Eagle Premier. Darn thing had the roughest shifts. No adjustment could ever smooth it out. From what I’ve heard about those things, rough shifts was probably one of the better owner experiences. Other owners at the time reported this transmission was prone to grenade at relatively low miles.
Have owned manuals since 2001, so no personal ownership experience with more modern units. Only driven them in rentals & company cars. Most seem pleasant enough, but can’t comment on durability.
I can concur on Eagle Premier shift “quality”… 4th to 3rd kickdown felt like it was goint to break the motor mounts.
Correction. The iron Torqueflite I erroneously called a 727 was actually designated the A466. 727 designation didn’t come about until the cast iron case was replaced with an aluminum case. I should know better, but being a senior, I seem to have more of these senior moments.
From a driveability perspective (and from car’s I have owned), my favorite may surprise some people – the A6LF2 (biggest version of what is generically called the A6) in my Kia Sedona. It is a 6 speed automatic that is a purely in-house design by Hyundai-Kia. Other than a single hard 1-2 shift right after backing out of my driveway (that it has done from new) it is smooth, doesn’t hunt, and has great ratios for the real world.
Runners up would be the 727 Torqueflite behind the 2bbl 383 in the 68 Newport I wrote up last week and the E4OD in my Club Wagon.
Worst – the Ford AOD, hands down. It was thoroughly unpleasant every single day.
runner up: the General Motors THM 2004R was more pleasant to live with, but offset that advantage by being extremely fragile.
I’ll second your praise of the Kia 6-speed. I’ve been pleased with the shifting in our 2018 Sedona, and particularly the Sportmatic shifting, which I use often. We also have the hard 1-2 shift pulling out of our driveway in the morning (we live on a busy road, so sometimes that first shift of the day is made under heavy throttle, so it can be a bit jarring). But overall, I’m happy with the Kia’s driveability.
Turbo Hydromatic 180s and 200s were my two worst automatic transmissions. They were under engineered. I had to rebuild the one in my 1978 Chevette twice. Pieces of junk. They also gave a lot of problems when they were put into the early 1980s GM Intermediates like Regals and Cutlass Supremes. My second least favorite was the three speeds automatics they put into mid 1980s Ford Escorts. They shifted into third gear way to early. They were tuned for fuel economy. My favorites were the Turbo Hydromatics in late 1960s and early 1970s GM cars shifted nice and had a good balance between power and economy. Chrysler Torqueflites of the 1960s and 1970s were also excellent automatics. I much prefer standards. The best shifter is a human being with experience driving a stick shift!
Agreed on the Metric 180 and 200. Pure junk. GM built many junk transmissions over the years: the Turboglide, the Buick Dual-Path (used in early Buick Specials), the Pontiac RotoHydramatic.
My favorite would have to be a TH400 or a 727.
Here’s a measuring stick for how much I like automatics. Don’t like any automatic when paired with an engine whose cylinder count multiplied by the speeds is under 18 24 is much better And I really liked it when I had 48 with my 2012 Dodge Charger. 3.7 with ZF 8 speed. Very smooth at low throttle, tight shifting at full throttle. RPM at 80 was something like 1500 and the car routinely did 32 miles per gallon at 80. But the best thing was the programming. This was the only automatic I ever drove that was happy to let the engine lug just a little bit. To be more specific when running under 2000 RPM and light throttle you could give it say 25 30% throttle without itdownshifting.. Which is pretty much how I drive a stick. And as the car had plenty of tractability it would easily take it instead of dropping down a gear or two like other automatics do and making a ton of fuss. But if you did want that downshift you could give it a quick blip of the throttle and it would downshift without lurching and chill out in that gear. Bravo to the people who programmed that. And I had the car but used with 20,000 miles on it and put 210,000 on it and like someone who said before me the engine and transmission acted exactly the same. Moreover the car was probably the most reliable mile per mile if not absolutely than any car I ever had. Perhaps will do a COAL on it
I was anti-automatic for a long time. And double that for CVT.
Then I drove my first CVT-equipped rental car, a ’13 or ’14 Corolla. And I liked it. Honestly, I liked it more than geared automatic transmissions. I liked it so much that I wound up buying an old Prius. Turns out I like CVT even more in hybrids.
But then life happened, and I wound up with a 4L60E behind 3/4 of an old small-block Chevy. The GMT800 groups/forums aren’t kind to this transmission; they say it’s fragile. But that’s coming from folks with V8 engines, maybe hopped up, and maybe big tires or lift kits or whatever. It seems perfectly adequate behind a 200hp V-6.
I hate the shift programming, but that’s the fault of the computers, not the transmission itself. “Normal” mode it clearly for MPG. It upshifts too early and is slow to downshift when necessary. Tow/Haul mode has better shift points, but makes the shifts super harsh to protect the guts. Especially given that I have the six, I really wish I’d found a truck with a stick shift, but such trucks were pretty rare by 2002, and used truck buyers can’t be too choosy.
I’ve driven a few CVTs and I don’t get the bellyaching about them. After a few minutes I didn’t even realise I was driving a CVT. I like how the CVT puts the motor at the torque peak on hard acceleration.
Yes, it is a little different but it is sure not a big deal in my opinion.
Not being a wrench turner, and not being a connoisseur of ATs, I have to turn to childhood memories of the Dynaflow in our 1950 Riviera which sounded and ran like an equally old displacement hull cabin cruiser.
Throttle settings and actual speed were rarely in synch unless steadily cruising on highways. There were no gear changes, starts dipped the rear end and stops dipped the front end (well that’s more suspension related but still added to the boat-like comparison).
It gave one the experience of boating without the need to own a boat.
The 1953 Packard’s Ultramatic was similar but had the added shift-like sensation of a single and gentle lockup.
Both were quiet and smooth.
The 1957 Chrysler’s 3-speed TorqueFlite was the polar opposite of the first two above named transmissions. Shifts were quick and rubberband-snap-like, even at partial throttle. A bit rude, maybe even crude, and absolutely glorious (in my teenage mind).
TorqueFlites served Mopar drivers well for a long time and became as legendary as the 225 slant six.
After that, most of the ATs in my life have been blurred in my busy adult-living memories with the sad realization that many were problematic (shortly after the expiration of warranties) in terms of reliability and performance until one-by-one, I swore off most automobile makes with those AT units.
The 5 speed A750F AT in my Tacoma thinks it is smarter than I am; I guess it may be after all.
BTW, the 2013 Tacoma AT has NO dip stick for the transmission. That’s how smart it thinks it is. ;-}
Not sure about old Prius ( first gen ? ) but the toyota e-cvt ( no belt one ,pic at right ) have nothing to do with their regular cvt found in their non -hybrid.
A shoutout to the ZF 4HP22 in the 1992 Jaguar I had in the mid 2000s. I bought the car at about 135,000 miles and it shifted imperceptibly. Three years later I traded it at 150,000 miles and it was still smooth as glass.
For me, it comes down to what I know best: the venerable THM350.
How many of these transmissions did GM produce? It had to be in the tens of millions. It was a simple, robust design that was very easy to rebuild. I could re and re one and have it rebuilt and back in the car the same day. They went almost exactly 200,000 km in taxi use, which is extremely rough in transmissions.
The worst, by far, was the unit in the 1981 Ford Escort, the split torque thingy. It is hard to believe Ford would sell such a poorly developed product.
On second thought, it’s easy to see why Ford did it, because they did stuff like this all the time.
Like to know how to make such a mess as in the picture put the transmission in reverse when going about 60mph I did such a daft thing in a jensen interceptor Oh dear
That’s called an Exploded View.
The automatic that most impressed (at the time) me in terms of driving was the much-maligned Chrysler A604 “Ultradrive”. It was the first OD four speed automatic that really seemed suited to the job, and it shifted remarkably smoothly, thanks to its electronically-controlled and adaptive shifting. It made driving our Grand Caravan a pleasure in terms of its drive train.
Yes, it did fail, but in retrospect, it failed very shortly after I had the fluid changed and the owners of the shop, who were Amsoil dealers, talked me into using their fluid. Using anything other than Mopar 4 fluid was the kiss of death.
Ironically, the 6-speed evolution of the A-604 is what is in my Promaster, and it’s not nearly as satisfying. The first four gears (essentially from the A-604) are ok, but 5th is too low, and 6th too high (numerically), leaving an unpleasantly large gap. And due to the Promaster’s large aerodynamic drag, shifting into 5th happens all-too often. It really needs 7 gears.
And there’s its aggressive descent control, shifting down into 5th or even 4th on highway grades to keep its speed at what it was, making it essentially impossible to take advantage of grades to roll a bit faster to build momentum for the next uphill. Annoying.
The 5-speed Honda in Stephanie’s TSX is excellent; it’s very easy to shift with the throttle without being too aggressive, and with the big four’s wide powerband, I don’t miss a sixth gear at all.
I hardly ever drive newer cars anymore like rentals and such, so I’m pretty clueless about most of them.
The A727 in our Dodge Chinook did exude a sense of solidity, and did its job admirably, but it badly needed a fourth OD gear.
Other than our Prius, I’ve only owned two-pedal cars in the form of pickups, an SUV and now a van, and no “traditional” V8 plus 3 speed AT combo’s. All have been adequate at worst, though the least pleasant to drive is my 3.5 Tacoma with the 6 speed. The transmission itself shifts fine, but the combination of a the engine’s torque curve, a few questionable ratios and the shift programming leave a lot to be desired. By contrast the ten speed on our (also 3.5 V6) twin-turbo Ford Transit is pretty amazing. I was worried about constant shifting with so many gears, but often the only thing I notice is the tach needle jumping up or down, it’s that smooth. Of course the EcoBoost’s 400 ft-lbs at 2200 rpm helps. The Tacoma peaks at 265 ft-lbs at 4600 rpm.
dman, I’ve heard about your impression of the Tacoma 3.5 6-speed trans/engine combo during a past post/comment and a reasonable explanation still eludes me.
My 2013 4.0 V6 5-Speed AT DCLB is [to me] a nice riding and smooth setup. But my other ride is a Miata, so any V6 AT pickup would seem smooth and nice riding in comparison.
2013 Tacoma 4.0 5-Speed AT
Torque: 266 lb-ft @ 4,000 rpm,
HP: 236 hp @ 5,200 rpm.
I believe your 3.5’s 6-Speed AT numbers are:
Torque: 265 lb-ft @ 4,600 rpm (as you noted)
HP: 278 hp @ 6,000 rpm
Also, the 3.5 is an Atkinson-cycle design; the 4.0 is not.
The newer 3.5 has a lot more HP than the 4.0 but the same torque, albeit the torque needing 600 more RPM to be equal.
I know Americans talk HP but drive torque but with one extra gear I’d think Toyota could make it all work.
My Tacoma’s 5-speed is always looking around for a good ratio, but unless I opt to pay attention it seems pretty transparent.
Anyone care to help dman and me understand what is going on here?
I’ve only driven a few urban miles in a 4.0 with 5 speed AT Tacoma so I can’t make a direct comparison. And to be clear, my setup is fine and after 6 years and 90k miles I’m used to it. But without digging out the ratios, I think the tall 6th, coupled with close 3-4-5 ratios, creates a similar problem to what Paul describes with his van. Cruising at 2000 rpm in 6th at highway speed requires a downshift for any acceleration, a slight grade like an overpass, or even a gusty of headwind. Yet more serious power requires two or even three downshifts which are noticeable … the result is that freeway driving in the mountain West seems to be ok at 1800-2000 rpm or need 4000+ rpm. This is even more noticeable using cruise control. The far less powerful 3.4 V6 and 4.5 I6 with 4 speeds in my T100 and Land Cruiser respectively, were less fickle, though never as quick. Around town the Tacoma works very well.
The Fordamatic 2 speed in my 59 Ford was a pos, just like the whole car. Didn’t help the bands were loose. Now my 2014 Acura 5 speed is great, made even better with the paddle shifters when needed. Progress.
I’m a Ford guy, but sentimental choice is still Powerglide, which my first car had. Only a 283, but I guess the torque did what it had to do.
No more recent nominee in particular, but it was a big step when Detroit started offering the 4-speed with an over-drivey top gear. That plus the lockup led to some nice gas-mileage improvements!
(I’ve still never driven a CVT car, and would like to know what they’re like.)
In my eyes any three speed automatic mated to a low horsepower and low torque engine is the worst. What that specific low output number is I don’t know as it depends on several factors. For most cars since the early 80s I’d say 70 hp and 70 ft lbs torque. Every car I’ve driven with a similar combination simply couldn’t get out of its own way. Highway speed cruising with low engine rpm meant passing required a kick-down to second at ridiculously high rpm. While cruising at high rpm resulted in increased fuel consumption and driver fatigue. Those of us that valued fuel efficient low output engines but unwilling to tolerate such design compromise had no choice but to go with 4-6 speed manual transmissions.
My least favorite? The notorious, infamous GM ‘Slim Jim’ (forgot the technical name) from the early 60`. A friend made a lot of money selling repair and rebuilding kits for it, well into the mid 70s`.
Roto Hydramatic – and yes, they proved not to be a very reliable design as they aged. Worked on a few of them. Prone to leaks from the high pressures required by the design.
Most favorite would be an automatic that lasts the life of the car. Beyond that I can’t make many claims since I have driven a manual since 1980. In my fleet I have one 727, one Cruise-O-Matic, one C6, and two C4 transmissions. I learned early on that routinely changing out the fluid in a C4 kept it happy as the one in my Cougar had issues at 35,000 miles. After a considerable attention to parts for the rebuild to deal with more power later on it has been trouble free.
The wife’s Mazda 3 has a 6 speed auto which seems fine. I definitely do not like anything more than 6 since the cars I drove with more can’t seem to make up their minds on what gear to be using at times. You can almost see my right arm looking to shift the car.
Oh, forgot the Sable’s AX4N auto which I know was replaced before I got the car. Been off the road for four years but back on next year after I rebuild the short block. That trans can have one shortcoming where the splines on the pump shaft wear and the car won’t shift. Already have a new replacement to install when engine out.
Any CVT or DCT that lacks a no-creep mode (short of shifting into neutral). Replicates the greatest flaw of the torque converter/planetary gearset while slowly killing the unit.
At least with one-pedal driving being a major attraction of electrification, we don’t need to worry about EVs being hard-wired to move with the driver’s foot off and away from the accelerator pedal. Yet.
Best: THM400, which I’ve had in a Silver Shadow, XJ12L and Coupe DeVille. Ideal partner to a large motor.
Worst: Saturn MP7 on my father’s SL2. The electronic logic was completely counterintuitive and frequently abruptly jerked down 2 gears out of nowhere.
I am also in the pro CVT camp. The better ones are simply smoother than comparable multi gear automatics as well as being more efficient.
In ’78 I bought a used base ’70 Olds Cutless sedan with I assume, the GM 350. It had 90K on the clock, & I took it to 238K over the next 7-8 years. It had developed a slow leak over the years that got worse. & worse, to where eventially I was pouring in a quart of Dextron every other week. I couldn’t tell from where the leak came from, only that a small puddle would appear on the driveway, but a ratty towel wipe would cure the problem. This went on for years until on one run going back home from a sales call 30 miles away, I noticed some tranny slippage. After stopping, the dip stick showed NO fluid, & I quickly poured in the two quarts I had in the trunk. I could now see a steady stream of leakage, so I just got in & kept going. I made it home, & the next day put two more quarts in, & drove it to my local mechanic, who in the past, couldn’t find the leak source either. This time he did. The dip stick tube was cracked right at the point where it was attached to the tranny housing. The mechanic did a weld job, & cured the problem. Looking back, perhaps the constant renewal of fluid kept the tranny happy, but I figured that last desperate run home probably ruined something internal. But, nope….that thing kept shifting like new ’til the car’s suspension gave out, & was towed off to the bone yard. That tranny was one tough cookie.
My first automatic was a 62 Ford Galaxie convertible 352 and a cast iron automatic. My brother and I swapped out the trans 3 times do to cracked cases. Junkyard warrantied them but what a pain to swap. The final tranny that worked had one quirk, it always started out in 2nd gear. So you could manually select 1st and then slip it into drive. Thankfully I never had to drive that pig in rush hour traffic. Those cast iron pigs were heavy and their habit of cracking the case internally, never again. GM 700R4 was a total disaster. I was employed by GM when this pile of crap was released. The updates and TSB bulletins were overwhelming the shop manual shelving. The transmission was so bad that GM opened a remanufacturing business to cope with the mess. After the 62 Ford I’ve never had a trans failure. 68 Cougar C6, 78 Futura C4, 80 Chevette TH180, 84 T-Bird AOD, 88 Tempo 3spd transaxle, 91 Probe V6 4spd transaxle, 96 Taurus 4spd, 98 Toyota Avalon, ’08 VW DSG, ’08 Mustang GT 5 spd auto, ’10 Fusion Sport Aisin 6spd, ’15 Cadillac ATS4 6spd, ’18 F150 10spd. The AOD provided much better fuel economy. The Fusion Sport 3.5L V6 Aisin 6spd was fantastic, best 4dr mid-size I ever owned, driving in the mountains out west was effortless. My F150 though is the real cats meow. This is the vehicle I dreamed of back in the early 70’s, ten speed trans and a turbo 3.5L V6. Its almost like driving a semi with a 13 speed. When I’m towing there is always a gear to keep it in the power band. No revving the piss out of it only to shift into the next gear and have it fall flat on its face and have to downshift again. Makes you wonder how much better some of the cars and trucks in the past would have been had they has 2 or three more gears in the transmissions. Its not like there was some wonderful break thru that suddenly allowed more gears to be put in a transmission.
You are aware of their green dot cruise-o-matic? Where the transmission starts out in 1st if the shift lever is on the green dot and when on the white dot starts off in 2nd. That is in my 65 F-100 and could be found in the 65/66 C4. This was due to the valve body found in those transmissions. When I researched rebuilding my C4, in 1971, I made the mistake of buying such a valve body, which the mechanic noticed and so wasn’t installed. Still have that valve body wrapped up in the Ford box in the garage. It would work in my F-100 if ever needed.
Most: THM400/425, THM350, TF727 (water cooled)
Least: Roto-matic Slim Jim Hydramatic
My father had an ’83 Chevy G20 van conversion with 305 and the overdrive automatic. (700R4?). Shifted fine, but grenaded at maybe 60K.
Least favorite? The 3 speed A413 TorqueFlite transaxles in my Plymouth Sundance Duster and Neon. Three rebuilds / replacements between two cars. Utter junk.
Most favorite? Any other automatic transmission that DIDN’T hand grenade on me.
Great question!
My least favorite was an automatic we had in an early model Ford Escort. If anyone has driven those, the character flaw was to run up and dump quickly to the next gear. When slowing down, they did that in reverse. The Ford said that the newer models coming out later would be corrected.
And I’d say my favorite is a toss up between the unit in our 2013 Ram Larime and our current 2022 Silverado with 5.3 (I believe it is an 8 speed)
Those two always so silky smooth when shifting, whether up load or not.
Not a lot of experience here, as I’ve mostly driven manuals.
Okay: Borg Warner 35 – Mostly did what was needed, would have liked more part-throttle kickdown. My first car though, and I guess I was rough on it.
Love: ’00 Mitsubishi Diamante – Brilliant.
Hate: Nissan CVT in a friend’s SUV that locked up and left us stranded one night.
Update – should say that I’m not anti-CVT as the one in my daughter’s Honda is great. But I haven’t driven it myself, only been a passenger. She’s a bit of a gearhead, and she’s happy with it.
I’m just anti-CVTs that break down.
Ford Focus Powershift has to be one of the worst of modern times. It destroyed the reputation of an otherwise perfectly good car. (I realize it is really 2 manual transmissions and a clutch working together…but sold as an automatic.)
Favouites? Any of the TH-350 or 400 family. Still cheap to rebuild. Honourable mention to the 4L60 in my Commodore. 250,000 Km, zero issues.
Least favourite? BW 35. I confess it has been 40 years since I worked on one, so I may be wrong here. Two band adjustments and using a drill bit as a gauge to get the clearance right. And the braces/brackets that ran from the engine sump bolts to the trans pan bolts. They never lined back up without loosening their sump bolts.
I’
Overhauled my first auto trans in my hand-me-down (Mother’s car) ’66 Biscayne 283/Powerglide as a high-schooler. Had a magazine article as a guide. Put it back in the car, and it wouldn’t engage any gears. Kinda-sorta engaged gears, but not really. Towed it to the local trans shop; everyone including me figured I’d screwed-up something important (read: expensive.)
In fact, the only thing I’d pooched was the manual-valve linkage to the manual shaft. A simple pan-drop to correctly attach the linkage, re-fill with fluid, and it worked great until that car was “done” years later. But I never “liked” Potatoglides. They’re a fine “race” transmission in certain classes, but they’re the death of performance in a low-powered, heavy vehicle.
Eventually bought a ’69 Impala; 350/Glide; and the glide disappeared shortly thereafter in favor of a core THM400 I’d overhauled in Trade School. I’ve loved ‘400s ever since.
All the gears in the back, all the clutches in the front. No pistons in the case that have to be pressed-out using special tools. For practical purposes, there’s no band adjustment needed. (The two bands can be “adjusted” using different-length apply pins; but almost no-one ever bothers. The trans gets assembled using the apply pins GM put into it to begin with.) A monkey could do a quickie overhaul on a THM400. And in Drive, they’ve got the absolute most-simple gear-change system.
At a stop, drop the shift lever into “D”. You get first gear when the Forward clutch applies. Nothing else is actively applied, but a one-way clutch holds due to the basic design of one-way clutches. Speed increases, the intermediate clutch applies and the Forward clutch remains engaged to get 2nd gear. Nothing is actively released, but again the one-way clutches do what comes naturally. Again speed increases, and the Direct clutch engages for third gear (direct drive.) Neither of the previous two clutches have to be disengaged; and again the one-way clutches just do their thing with no outside “control” needed. As you slow down, the opposite happens–the Direct clutch is released to drop into 2nd; the Intermediate clutch is released to drop into 1st. There’s no need to coordinate one friction element (clutch or band) engaging while another disengages to make a shift. It’s brilliant engineering. The TorqueFlite shift strategy is strongly related to the 400 shift strategy, except that it’s missing one critical parts-set; the TorqueFlite has to coordinate releasing the front band (applied in 2nd gear) while applying a clutch to complete it’s shift from second to third–and the timing/speed of the apply and the release is critical in terms of shift smoothness.
The 425 fwd version of the 400 has all the good traits of the 400; although it’s more complex due to the chain-drive system and attached differential. Some of the pieces inside rotate the opposite direction from the 400, therefore the one-way clutches lock in the opposite direction. And there’s an extra-heavy-duty rwd version called the 475, used in Motorhomes and such. Like the 425, the clutch drums tend to have more internal clutch plates for higher torque capacity. The geartrain has less angle on the helical gears which makes more noise, but produces less thrust force on the thrust bearings; and the gears tend to be stronger. A light-duty version of the 400 has fewer clutches in the drums; and a smaller-diameter tailshaft and tailshaft housing. The tailshaft housing is marked “375”. The light-duty parts can be replaced as desired to convert to “400” torque capacity.
The only thing the 400-series transmissions don’t have is an overdrive gear and a lockup torque converter (although some ’65–’67 400s and 425s had a dual-pitch stator in the torque converter that can switch between high stall speed and low stall speed.) But the 4L80E is strongly based on the 400 while having more complexity, a lockup torque converter, the same lovely 1–2–3 shift strategy, and an overdrive gear. A downside is that it takes a sophisticated electronics package to control the two electric shift solenoids, the torque converter solenoid, and the electronically-regulated pressure relief valve because the governor and the vacuum modulator were eliminated, and the valve body passages dramatically changed.
You taught me a lot.
Thank you!
My least favorite is the Ford F-4EAT transaxle in our 95 Escort, It was a decent mid 90s 4 speed auto when it worked but it failed and successive repairs also failed, so in hindsight I should have forked out for the factory rebuilt unit and saved aggro and money. FWIW the used transaxle we finally installed worked fine until we scrapped the car due to cumulative worn out stuff.
Other than that the automatics in our various cars and trucks have been unremarkable apart form the Saturn SL2 which developed the usual Saturn reverse slam from buildup in the valve body, and eventually killed the car when the differential grenaded, also a known bug in the Saturn S series.
Honorable mention to the Mazda FW6AX-EL six speed in our CX-5 which is so much better than a CVT or DSG and the Ford 4R70W in our pickup.
Favorite is the 727 or 904. Bought a 30 year old Dart with a 318/904, checked that the fluid was full, daily drove it 7 years and never touched it again. My ’65 Chrysler is 383/727. It did need a rebuild this year, but I have no Idea how many miles on the transmission, at least 85,000 by me.
Least favorite is whatever they put in Aerostars. Had a ’91 & a ’93 and had multiple transmission problems with both of them.
I’m surprised by no mention of the Mercedes 722.6 – the 5g tronic. Since 1996 it’s been the benchmark modern automatic used by MB for their smallest cars up to the Maybach and SLR McLaren, and had the best shifer I’ve ever used (pre tiptronic) as well as 2 speed reverse – typical Mercedes Benz over engineering.
I would also say their earlier 4 speed boxes were quite good as well. I liked both the ‘2nd gear start’ variety in my 201 and 126, as well as the 4 speed in my ’75 240d which I thought would be dangerously slow, but is surprisingly good and shifts when I think it should probably more quickly than I could move a balky Mercedes Manual from gear to gear.
My Dad bought a 1973 Chevy Suburban new….had the 350 V-8 and Turbo hydramatic transmission.
At 50,000 miles, after a fluid change, the transmission would no longer shift into 3rd gear.
It would shift as far as 2nd but go no higher.
It did not behave the same way as if the shifter was placed in L2. In low 2, the engine would be in compression braking mode with RPM’s staying up.
With the transmission problem and the selecter in “D” RPM’s would stay up under throttle but if you took your foot off the gas, the engine would return to idle, despite being stuck in 2nd gear.
Then as you got back onto the gas, the engine would rev back up to match the speed you were going.
A transmission shop ended up rebuilding the transmission.
Old school favorite was the two 727 Torqueflites I had in my ’74 Roadrunner and my ’77 Power wagon. The Roadrunner’s trans was fine, and even better after a shift kit was installed about a day after the warranty expired. It had zero issues for the 3 years I had the car, and the 7 the second owner had on it before something went out in it. The RR is alive and more than well in Las Vegas with a stroker 440 (about 487 C.I now), the original cased trans and a Gear Vendor’s overdrive added to keep the revs from the 3.92 gears down for a nice highway cruise. I messed up the throttle linkage when I put a new intake and 4 barrel carb on the PW, and blew the trans up. After a rebuild with a shift kit, it was fantastic.
With later vehicles, the champ is the ZF 8 Speed in my Challenger Scat Pack. I can’t really say one single thing bad about it. It never hunts for a gear, it shifts at warp speed when it’s running hard, and basically just does the job with total competance. My friend’s 10 speeds in his Fords are a mess, they can’t seem to find the right gear most of the time, and it’s his main complaint about both his Mustang and F150. When he drives my car, he just mutters that Ford should hire the programmers of the ZF and let them fix the 10 speed. But then it appears GM has it right, so why can’t Ford do it?
Interesting question.
Least favourite, the Chrysler 904 in my 1984 Wagoneer (nee Cherokee) The Steyer-built converter broke at 20k miles filling the transmission with metal filings, requiring a rebuild.
I eventually went through three converters in that thing. Fortunately for the subsequent failures, I learned to identify a broken converter due to the unusual noise, and replace it before the transmission was ruined again.
Perhaps we can’t blame the 904 itself with the failure but it was damned by association with that terrible converter design.
Favorite? Later model THM 440s and 700R4’s. My 93 Marquis has an AOD in its final version that is equally delightful. All are reliable and serve up the right gear at the right time. My 2000 Volvo has a 5 speed Aisin Warner unit that is also flawless.
For favourite 3 speed, its a toss up between the THM 350 , THM 400 and the Ford FMX. I prefer the FMX over the Ford C6. The latter’s second gear band can provide an erratic, rubbery shift unless its precisely adjusted.
Best? It’s hard to fault the 727/904 TorqueFlites, whether behind my 273 or my Dad’s 401 AMX, or various friends mopars they gave yeoman service.
Worst? The Borg-Warners used for so long by AMC. They just didn’t stand up to heavy use.
Honorable mention? The ancient HydraMatics, especially the Dual-Range ones. Not the most sophisticated, not the smoothest, but rugged and dependable. My Mom’s ’53 Pontiac 8 was an el-cheapo oil burning special when she got it in ’62 but it ran and the transmission, except for a minor leak, never missed a beat.
My 1987 Olds Cutlass Ciera Brougham with the Buick 3.8L engine was an excellent first car for me as an 18-20 year old in the mid-1990s – quick, smooth, roomy (well, the front seats anyway) and comfortable on the ~5 hour road trips to and from college, got reasonable gas mileage, and its baby blue metallic paint, tasteful brightwork, pop up sunroof, fake-wire wheel covers and whitewall tires looked darn classy when properly washed and waxed. Add in an aftermarket Sony head unit with a CD player to replace the original Delco cassette unit and I was over the moon with it.
Unfortunately, the 3-speed TH-125C automatic was evidently way undersized for the torque of the big-ish engine, and I ended up chewing through two of them before the car had even gotten to 65k miles, both times just after cruising at a steady 70 mph along flat terrain for at least a couple of hours. The first time stranded me halfway between school and home, in a forelorn Wichita strip mall parking lot one freezing Christmas Eve, where I had to wait 3 hours for my dad to come rescue me. After getting a factory replacement at a cost of probably 25% of the car’s value, the second one went maybe another 15k miles before self destructing, this time in my parents’ driveway. My dad took me to buy a lightly-used Mercury Sable on heavy discount that same day, a significantly more reliable car which I never came close to loving, especially compared to my Ciera.
I remember tearing up when they towed my baby away. That was the last GM I ever owned, and never seriously considered buying another in all the years since. Funnily enough, I’ve never owned another car with even a single transmission issue since then.
So yeah, the GM TH125 is my personal Worst Transmission Ever.
61-63 Oldsmobile Slimjim was the worst. They ALL will crack the torus cover eventually. The best were all the 400 series GM automatics. 400, 425, 475 and the 4L80E are long lasting and nearly unbreakable!