CC DIY: 2004 Buick Le Sabre – Filters, Fluids, And Upgrade GM 4t65e

Cars, circa 2004, many times don’t have a cover under the engine like newer cars. Less to remove but more dirt. I had to hit the bottom with a brake cleaner to remove oil and dirt. What I saw means next month will be busy, but today I’ll concentrate on the fluids and filters. The car is at 63,000 miles.

An oil change is as straightforward as one can get on most cars. Drain oil pan and remove filter. Interestingly I have three different size filter wrenches for removing recalcitrant filters and yet none fit this filter. Heavy-duty rubber gloves provided the grip to get things started. Add Valvoline 5W-30 synthetic and done. Next the GM 4t65e transmission found in many GM cars between 1997-07.

Oh for the days of the Ford C4 with the simple square transmission pan. This one is shaped like Africa and so I studied how I wanted to unbolt it. The driveway slanted back a little so I had that going for me and managed to get all the oil in the container. Draining took about 30 minutes as I released the bolts bit by bit so I didn’t get an uncontrollable cascade.

Here is what we see with the pan off. The filter in the back and the accumulator on the front right. The accumulator is coming out along with the filter.

With those two pieces out I have a pretty clean and drippy bottom for the next few hours. The filter alone must have held 1/2 quart of fluid so one needs to be aware of that so you don’t spill it on the pavement. Same for the accumulator which doesn’t release all its fluid despite tipping over.

Oil pan bolts went into a cleaner to soak. The accumulator bolts just sit. The filter goes in the trash and the accumulator body comes into the garage with me.

The top half here shows some of that crud that one sees in automatics and can contaminate the pressure control solenoid (ECP) leading to transmission problems in the GM 4t65e transmission. I actually had very little on the magnet in the pan while this was blown out with brake cleaner after this picture.

I’m using the Transgo kit here to firm up the 1-2 and 2-3 shift in the car. The new springs are laid out here. The large one replaces a similar sized one inside the accumulator but is clearly stiffer. The 2-3 shift side will get three springs to replace the original two. There are also three spacers two of which go inside.

The 1-2 on the right is done while the 2-3 side shows the springs inside with a spacer before placing the piston back in with a snap.

Last piston in place, spacer around rod, metal gasket in place and old large springs out. Now it is just a matter of bolting the two sides to each other and I am done with this portion of the job. Now the filter seal.

With the accumulator done it is time to deal with the filter. some say you can use the seal left after removing the filter. Others say change it out. There is a special tool for this which I don’t have but saw a way to get the seal out. A chisel placed right against the lip and then tapped gently with a small hammer deforms the edge and starts to push it in. Push it in enough, then I used a small slot screwdriver to push against the seal now that I created an entry point and then removed with needle nose pliers. New seal tapped in with the small hammer and a socket that matched the diameter of the seal lip.

With the seal in I can now put the accumulator back in and hand tighten the bolts. They weren’t tight to begin with and probably around 40 lbs. I also added the recommended bracket to attach the one loose fitting line to the middle line which is firmly pushed into the accumulator. Now this is mainly a safety measure as it may or may not ever come off but I am in here so do it.

With the filter gently tapped into the new seal I am ready to seal up the transmission. You might notice there is now a new magnet on the bottom of the filter as per a TSB from GM. The set purchased contains two magnets as the one in the pan is chintzy.

Those bolt heads were a dirty mess and I don’t tolerate dirty bolts when doing any job whether on my cars or on the USS Hornet. With them cleaned up, and the new magnet in place I am ready to bolt on. Ah, but note that is not the original pan but a Dorman pan because it has a drain plug and is highly recommended. No messy fluid changes in the future. I was pleased with the look. The bottom will need a steam bath later on. That after I tackle the oil leak which will be the next job. The struts were a moderate task, this job a minor task, but the next job is a major one as intake, gaskets, water pump, tensioner, thermostat, coolant, belt, and those plastic elbows all replaced. In the meantime the test drive was uneventful and all was good to go. One thing about this car and that is it will be still running fine after I am gone assuming you can get gas.

Just one more repair and maintenance article. As for this update, I had one full day of driving since it was hot and the AC works great in this car. The 1-2 shift which was always imperceptible under normal acceleration is now somewhat perceptible. When moving at 30 mph and then hitting the gas so the car down shifts the engagement is definitely firmer than before. Exactly what I want to maximize transmission life.