jbakyy

Hello,
I have a small tranny leak in my 1971 4 speed, does anyone suggest any additives to stop the leak?
Thanks

Jud Chapin

No, it's always best to fix it. If you're uncertain where the leak is, clean the exterior to locate it. Be aware of the wind when moving as it will push the gear oil to the rear of the tranny. Take some short, slow trips and see if you can see the leaks origin. Good luck.

TimAT

99% of all additives are snake oil. Like Jud said, clean it up and see if you can pinpoint the drip. Shifter shaft seals, speedo drive gear seal, and the 4 speed favorite, the mid plate.

jbakyy

Thanks, I have taken it to gm twice and still leaks. No miracle cure like Lucas or anything, huh?

TimAT

Where do the drips show up?

jbakyy

Mostly in the middle of the rear cross member. Thanks

TimAT

I'd bet it's the midplate. Not a real easy fix, but it can be done. I did mine not long ago. Got a seal kit from NAPA, pulled it apart and new gaskets. I was wanting to look at the brass synchro rings anyway. Thin coat of RTV on the midplate gaskets and no more drip.
Just because it's really easy, you might replace the seals on the speedo adapter first.

Big2Bird

Short of draining the oil out and filling it with concrete, no.

jbakyy

Thanks to big of a job for me.

TimAT

There should be a trans shop around that won't kill you on labor- the seal kit was under $30 at NAPA. IF you can pull the trans, you can save some $$. Even a shop that does 4x4's should be able to throw a seal kit in there..

jbakyy

Thanks

gungatim

you could spray the whole tranny with a can of that seal stuff they sell on TV....

bashcraft

I didn't know this stuff existed...

TimAT

Bashcraft- more snake oil. That additive swells the seals in an automatic so it'll last a little while longer. I've rebuilt a couple of autos that someone had added something like that or maybe even the same stuff. The seals were limp when I took them out. no definition to the lip or even the body that holds the seals into the pistons.

bashcraft

I've heard of people adding brake fluid to their auto trannys to soften the seals.

capevettes

AT-205 Re-Seal works and won't hurt the transmission. I have never been an advocate of magic in a bottle solutions. In almost every case you really need to fix what's causing the leak. I had tried everything with my leaking Turbo 400 in my 68 BB. If my car sat for a few days I would have a puddle under it. I added a bottle of this after it had been recommended to me by someone I trust. It worked. It hasn't leaked a drop in over a year and the tranny shifts perfectly. Worth a try. It may work. It conditions the seals to expand and seal better. It did for me. Auto Zone carries it and it is available through Amazon.

AzMotorhead

Problem is that on a 4spd trans the only rubber seals are.
Shift levers,speedo O ring,and rear output.
The remaining case seals are paper gaskets.
Chances are seal conditioner is not going to work

capevettes

Good point Az. It has a better shot of working in an auto but still worth a shot IMO. Nothing to lose.

Jud Chapin

Since you paid GM for the repair, I'd take it back and tell them to fix the damn thing. Get the svc. mgr. involved and tell him their work is unacceptable.

Does it leak when parked? If so, clean the outer surface, park it, and wait to see where the drippings are originating. Then take pics and show them to the svc. mgr. This ain't rocket science and should be an easy fix for someone who knows what they are doing.

jbakyy

I took to gm 4 years ago, I doubt they will take it apart again for free. Yes it does leak when just sitting. Thanks