Transmisson Question

[unbludictable]

I have a 350/th350 in my '76 GMC High Sierra. I bought the TH350 from a guy I know and the tranny has preformed well for about a yr now it leaks most of the tranny fluid ove night !

I have changed the gasket twice and it still leaks! An ASC Trained Mechaic friend of mine changed it and IT LEAKED!

My Question: The tranny is Aluminum, should my pan be iron? If not, how can I find the pan to fit my tranny? Or is it the pan?

I read the article on the weep hole I don't know where the fluid is comming from. Help

[zieg85]

All the fluid leaking overnight???  That is a bunch, should be fairly easy to find the leak. 

[eventhorizon66]

Warped pan, rear seal, cracked case.  If you are loosing ALL your fluid, that's easy.  You have a hole in the bottom of your pan.

[VileZambonie]

I just had a TH350 with cronic overnight leakage that I fixed. The detent cable had a pinhole in it and as the torque converter drains there goes your fluid. The speedo, shift shaft seal, tailshaft seal and if it's a C O-ring on the connector are all prone to leakage. If it's the tc seal or pump seal it will be wet behind the converter.

[unbludictable]

Well, I say ALL because when I put it in gear there is not enough pressure to make it change gears! It don't even think about moving. Fluid drips all along the lip of the pan, and I can't tell if it's the pan, gasket, or what! I know what, I have bought 6 gallons of fluid from Walmart at almost $10 each just to see it pissed out on the ground the next day is getting old fast!

Is this an easy fix? Or headache?

[VileZambonie]

Clean it off. Wipe down the detent cable real good. If it's wet there's a hole in it.