DIY transmission tools


Veteran Member
Aug 27, 2003
The Netherlands
Thought I share some pics of tools I've modified/fabricated to work on/with auto transmissions. Since I'm messing more and more with it, it's convenient to have some of this stuff without braking your wallet on original equipment.

Holding fixture for the bench. I've had a 4L80, TH350 and TH400 in it, so you can say it's pretty universal as long as you make the bolt/handle long enough to fix different cases. The other side has a fixed 'pin' that goes into the opening on the case.
One more mod to make is a U-shaped bar (approx 5-6") to fix the top instead of the piece of wood.

Next is a tool that will make your life so much easier when working on a 4L80/TH400. Last assembly of drums to pull out (or first when assembling) in these transmissions weights probably 30-35kg. This is the way Jake is describing how to get it in/out:

Now you will need to lift the rear assembly and install. This rear assembly is relatively heavy. It requires you to lift by the center shaft, you cannot lift it by the center support as it will slide out of the reaction carrier.
I use a paper towel to pad it slightly, and grip the shaft between my middle and index finger. I lift it using one hand under the output carrier until I'm ready to set it into the case. Then all the weight is on your fingers for a few seconds. If you have a helper they may be able to hold the output shaft once it passes through the rear case hole and hole in the bench.

Save your self some headaches and fabricate something similar from a welding clamp:

This way you will be able to lift the whole assembly very easily by clamping the top of the center shaft just under the splines. Worked on both the 4L80e & TH400:

But wait,there is more: if you call within 15 minutes, you will be also able to use this tool to compress the 2/3 servo in the valve body in order to get the E-clip out. It's like having 2 tools for the price of one - it's amazing:

By grinding the end portion of a long screwdriver, you'll be able to get it between the case and the snap rings and easily 'twist' them out their grooves:

If you've ever disassembled a 4L80e or TH400 valve body, you know that for some unexplainable reason (at least to me) GM engineers have locked some of the valves with a pin, that is some 2 inches deep in the bore and only has one opening to get it in/out (blind hole). Since these are role-type retaining pins, they fit tight and won't come out without a fight. Although you could use a screw extractor, I've grinded the ends of a long tip pliers, works like a charm:

If you have no idea what to buy for your wifes next birthday or your wedding anniversary, here's a tip: get her a cutting board. Then you grab the old one, cut a couple of grooves and you'll never loose track on the valves coming out the valve body:
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Veteran Member
Aug 27, 2003
The Netherlands
Not directly usable on a Camaro, unless you're running a Torqueflite, but still an automatic transmission tool:

You can buy the correct tool (rare and probably expensive), buy an 8 point 5/16" or mm socket (couldn't find it here), or make your own tool from a piece of scrap and any size socket (that will fit between the plunger).



Veteran Member
Aug 27, 2003
The Netherlands
Tired of those roll pins in the valve body, especially in blind holes where you can't push them out?

Here's a simple tool that will save you some time and aggravation.
Take a metal saw blade and grind a taper to the backside. I used a bench grinder to do it. And that's it.....

Then you stick the tool inside the pin, turn it to compress the pin a bit and pull it out. Teeth on the tool will help to grab the pin.


Veteran Member
Lifetime Gold Member
Feb 12, 2011
atlanta, ga
latest item in stores NOW...forward clutch pack compressor tool!!!!
also known by many as ....
a piece of PVC pipe cutoff....just to compress wave spring to get out the lock ring ...current price.....depends on if store is open...

BTW...good stuff there holland ;)