Technical TH350 Pan leak

Dipstick tube seal #1259475, available from most GM dealers for less than $4.00. This is a multi-lip seal which will work in place of the o-ring type seal.

 

You need a matching dipstick tube to use that seal, though.

 

I know there's a newer style tube without the o-ring groove that was used with the newer multi-lip seal. But I seem to recall using the multi-lip seal on the older tubes with the o-ring groove. We've had a couple leakers in the shop over the years though where someone's tried using an o-ring on a tube without the groove and that never works out well...

 

This style is really troublesome especially if it's a cheap aftermarket deal.



With this style the end of the tube is swaged down to fit in the seal. Much better if you ask me.


The 2 cannot cross bread

 

I was scratching my head over this one for ages. I replaced the pan with a new aluminium pan and new gasket and still it leaked. But only from the two bolt holes that connect to the B&M shifter. So, I thought it must be seeping through the spacers or I haven't torqued those bolts up or I have over tightened etc. Stewed over it for ages. Ended up doing what I should have done ages ago and took it to a transmission shop.
Shifter seal linkage leak was the problem. An easy fix. Who would have thought that it could seep down there and form two perfect droplets underneath those two pan bolts? It had me stumped.

 

that seal is the first place I would have looked. I first encountered leaking shift shaft seals on a torqueflite when I was about 15.

 

So glad I saw this post. very helpful. thanks guys

 

chased a leak for a year, turned out the speedometer cable "torpedo" and the gear were worn out....got mine from Amazon.com, just make sure you get the correct gear, they are color coded!