TH350 leakage issue

[next69]

I have a TH350 in my Nova that has been leaking for several months. I have a TCI high capacity pan (2 additional quarts) and for some reason I can not conquer this problem. I tried the felt gasket that came with the pan, cork, rubber and finally a silicone gasket and it won't stop. I think the next step is to take the pan someplace to see if it was properly machined but if any of you have some pointers it would be greatly appreciated as I am tired of changing gaskets.

[pontiacbird]

maybe the leak problem is not the pan . he can origin elsewhere and flow up to pan join . do you have removed the inspection cover ? the tork oil seal , pump o-ring and pump bolt can leak . the speedo gear housing , gouverner cover , modulator , yoke oil seal and vent tube can leak too . personnally I already haved probleme like your and the leak was , the pump bolt seal ! good luck !

[Bad Bowtie]

Along the lines with pontiac bird, make sure you check the seal for the gear selector shaft on the side of the tranny. I had one on an 80 vette that a customer of mine could not find and after I did a thorough cleaning of the pan area noticed the fluid coming from this seal and let me tell you it was a pain in @@@ to change. The narrow corvette tunnel made it even that much harder too. If you happen to change this seal make sure you dont damage the lip trying to get it over the shaft. I would think if you have the TCI cast aluminum pan it wouldn't be that anyway the flanges are pretty thick and would seal better than the metal ones.
Jack

[next69]

I had a chance to clean up the tranny and you were right, it was the gear selector seal. I was wondering what the procedure is for exchanging this seal and if there are any special tools required? I want to make sure I am not getting into something I can't finish and end up having to have my car transported to a trans shop, especially if I can drive it there now. All advice would be greatly appreciated.

[Texas Hotrod]

I have a special puller made just for thet type of seal. It slips over the shift shaft and it threads into the rubber part of the seal. You screw in the bolt on the end of the puller and it forces the seal out.
It comes w/an installer too. Grease up the seal/shaft and hammer in the new one.
In and out in less than 5 minutes. I got it from Matco (or Snap-On) years ago.

[next69]

I found the tool on Snap-On's site and it is just as you said a bolt, removal tool and installation tool. I was wondering one appears to be just a tube and the other has a hex end and a conical end. Could you please tell me which is the installer and which is the removal tool as well as any instruction you might have. Sorry for being so needy but I have never done tranny work and I want to get it right the first time. I did not mention this before but this seal was just replace at a shop a few months ago so I want to avoid the same result.

[Texas Hotrod]

The conical end has an aggressive thread cut into it, and it necks down at the end (like a pipe thread does).
Mine is old and might be dull, but I tap the end w/a hammer and turn it w/a wrench to thread it into the seal. Screw in the bolt in the end of it and it pulls the seal out.
The tubed tool is the installer. Put some grease on the shaft and on the seal and carefully slip the seal over the shaft. Hammer it in w/the installer and you're done. Don't put too much grease on the shaft. If you fill up the seal pocket, the seal won't go in far enough (grease won't compress). If there's enough room, you could install 2 seals.

Good luck.