Toolbox Classic: Snap-On “S-Wrench” – Adjusting A GM A-Body’s Doors The Right Way

A picture of an obscure wrench on my old garage floor is unglamorous, I know.  But this tool saved me hours of aggravation and heartbreak, and it’s the “right tool for the job,” a luxury that the home enthusiast isn’t always afforded.  It’s a Snap-On S-Wrench, designed so those hardworking body shop men and women could adjust the door hinge at the cowl of a GM vehicle. I’m not ashamed to tell you that I paid $60 plus shipping for this oddly shaped tool that is probably older than I am.  I’m even less ashamed to tell you it was worth it.

The part number on this quality American tool is S9606, with the fraction denoting that it has two 1/2 inch box ends.  Most of the sellers online are asking around $100 for this particular wrench, so I guess mine was actually a bargain.

I bought the tool because I didn’t want to do this again.  Two years ago, I disassembled the front end of my ’65 Skylark to fix some rust.  Somewhere in its 55 year past, the car took a pretty decent hit to the passenger side; I know this because I stripped the passenger door down to fix some rust two weeks before I used the Skylark as my wedding car back in 2005.  It had about an inch and a half of filler covering a cave-in the size of Carlsbad Caverns.  Without much time to work, I just filled it right back in, and it’s been there ever since.

I look happy enough anyway.

Regardless of my hackery and the hackery of previous owners, the door and fender have never gotten along well together.  The door has always had a tendency to rub the fender when it’s opened or closed, even though it should have plenty of clearance.  When I had the fender off in 2018, I decided to just move the door back a little to clear the fender, but the unsightly door to fender gap even bothered me, a guy who is notoriously nonplussed about such matters.  I decided to do something about it.

And this is why I’m so excited about my new/old Snap-On wrench.  As you can see, it would be nearly impossible to adjust the hinge at the cowl with the fender on the car; there’s just no room for a socket or any normal kind of wrench.

There is room for the S-Wrench, however, because it was designed (and priced) for the job.  It has two different ends so the mechanic can tackle the bolts from the top or bottom, whichever works best.  Here’s I’m addressing the bottom lower hinge bolts.  ***I know I need new door weatherstripping; thanks for not mentioning it.***

Barely visible between the door and the fender is the business end of the S-Wrench, doing its job to save me time and labor.

On an A-Body, there are also several places to adjust the fender with shims, including here inside the door opening.

And here under the hood, where you can adjust the fender for height.  Every move throws everything off balance, so adjusting doors and fenders takes time and patience, and most garage mechanics will have to make some compromises.  The real time to make these adjustments is when the car’s in primer, but we don’t always have that luxury.

Regardless, I got the alignment to a place where I’m satisfied with it, which is really all that matters.  After years of rust and collision repair, the bottom of the fender isn’t quite in the right spot, so the gap’s larger than I’d like down there.  That’s fine; I don’t want the door to rub, which is the reason for doing this in the first place.  I adjusted the door slightly inward compared to the fender for the same reason; that adjustment is done by way of the door hinge-to-door screws, a totally different operation needing a totally different set of tools.

The rear of the door also looks better than it did.  Every adjustment you make at the cowl also affects the height of the door at the rear, so more compromises must be made to get it all lined up, front and back, side to side.  I worked on it for several hours; a perfectionist would work several more.

So there you have it, the story of a tool that will probably spend the rest of my life lost in the toolbox; however, I’m glad to own it, glad to have used it, and maybe I’ll get to use it again someday.

Previous entries on my Skylark:

1965 Skylark Coal #1

1965 Skylark Coal #2

Curbside Case Study