Originally Posted by theslayer

Kind of a very brief DIY for anyone running into this problem anytime in the future.

My transmission input shaft was leaking, right after I had done a transmission rebuild (and replaced the input shaft seal with a new one). The symptom was oil pooling at the bottom where the bell housing meets the engine block.

Now, technically to replace this seal you have to take apart the whole transmission, and I wasn't about to do that again. Turns out if you are VERY VERY careful, you can extract the seal without taking apart the transmission. It is very important not to scratch the sealing surfaces of the seal, which are the input shaft surface and the surface on the case of the transmission.

Materials required:
-very thin wood-type screw
-very thin drill bit to match screw size
-drill
-screwdriver
-duct tape
-small hammer

1) Wrap duct tape around the screw and the drill bit. You want only the very tip of the drill bit exposed, and only the tip of the screw.

Ryan: I ended up using a 5/64 size bit

Ryan: If you go about this far deep you won't over run the channel.

Ryan: also try to make the punch in this center channel so the ribs on the back end protect the seat.

2) Set the screw, tip side on the seal roughly in the center (be careful not to scratch anything), and tap it with a hammer gently to make a small indentation for the drill bit. If you tap it too hard, you will push the seal in deeper and it will be harder to remove it. Remove screw.

3) Drill a small hole into the seal in the location you just marked with the screw. If the indentation was done properly, the drill bit shouldn't wander around and scratch other stuff. There is a metal thing inside the seal, and you want to drill into that. Again, be very careful not to scratch anything else.

Ryan: be careful about how hard you push but it's not too bad. The drill I used didn't really clear the input shaft so I just tried to keep the angle as shallow as possible.

4) Insert the tip of the screw into the hole, and start screwing it in. It should bite into the metal inside the seal. Do not screw it in too deep, or else you will risk having the tip of the screw scratch something.

Ryan I had to use two different sizes but eventually got the longer of the two screws in. I used a 90 degree plier and my punch as a fulcrum.

Optionally, remove the screw, dull the end with a file, and re-insert it.
5) Once the screw is sitting firmly, pull the seal out with pliers.

Ryan: it's out

6) Then go ahead and insert the new seal. I used a pvc tube with another tube as a seal driver. I also coated the exterior of the seal with a thin layer of permatex ultra grey gasket maker to help seal the outside, because I think that surface might have been scratched. I used a caliper to measure the seated depth of the seal at several points along its circumference. Follow the specs in the service manual.

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The PVC I got was 1.25" from Lowes and a cap. I brought the seal with me to test the diameter. Still undecided on what to coat with but I ended up using a light coat of diff fluid. Manual says MTF but I didn't have any.


Ryan: Using a caliper, I measured to 0.16-0.18 inch and called it squared


Sorry I do not have pictures; I had my old seal laying around somewhere with the screw in it but now I cannot find it anymore.

Originally Posted by Car Analogy

Awesome! Great work adding clarity and detail to an already great idea.

I'm wondering if its possible to use a pin vice instead of a drill, so you can get tight up against the input shaft, so drilled hole can be straight in, not a angled.

Pin vice = finger drill. Kinda like a jewlers screwdriver but with a tiny drill chuck at the end. Spin it back and forth to drill.

More time consuming, but maybe safer too. Less chance to go too far and scratch sealing surface.

Pin vice isn't expensive.