About ready to give up!

[72superBB]

Ok, I have changed the gasket once and then changed the pan to another one and have since changed the gasket twice on the new pan on my th400 tranny that I have. It still leaks.

I have changed the vacume modulator and it still leaks. I have put in a new speedo gear & new housing, and it still leaks. I have dropped the thing and changed the front & rear seal and it still leaks. WTF? I am at my wits end with it.

Any suggestions, anyone have one close that works fine and does not leak? I know mine is needing a rebuild. It shifts 1 & 2 ok, but takes it sweet a$$ time going into 3rd. I have to let off the gas for it to shift.

Ahhh. I feel better now that I have vented a little!

Thanks

Ron

[dion]

my TH350 leaks a little at the speedo cable but nowhere else, what kind of gaskest are you using?

[72superBB]

Where should the gasket be? the housing goes in the side of the tranny. No gasket there. (Should there be & where?) Then there is a little box thing that goes to the housing. SHe speedo cable from up top comes down & hooks to the side of that little box.

[Hooter]

when in doubt, silicone it

[dtlilly]

Just a shot in the dark here, but take off your dust cover to see if the fluid is leaking from the torque converter. Is it coming from the fill tube where it goes in to the tranny?

[Rooster's 67]

at the shop we wash down the whole component(in this case the trans) .
We take it to the carwah and jack it up then pressure wash the major portions clean then put it on the lift and use about 2 cans of brake clean to remove all the areas near gaskets and seals that are dirty/oily then blow it dry then start and run....watching for leaks. if no leak then short drive and back to the lift....still no leak longer drive....back to lift repeat till leak is found.

you may have more than one. start with the big obvious ones.......

but it also sounds like you have covered the obvious leak points.

the speedo gear housing has an o-ring type seal.
did you check the pan flange for compression wapring around the bolt holes?

just a couple thouhts...
good luck

[jhow66]

Bet it is leaking from the two places you have not checked yet --the shift rod that comes out of the trans--has 2 o-rings-one inside and one outside or the kick down switch that the wire hooks too. It will run down and make it look like it is the pan. Had same problem with my 65 GMC with 400 turbo.

[72superBB]

jhow66
How do you change those two places? Do I have to pull the pan to get to them?

Thanks.

Ron

[jhow66]

Afraid so--sorry.

[BUXMAN66]

just to throw this out there to consider.... my buddy's house has a hell of a steep driveway. i was parking on it ,but noticed a spot the sixe of your palm leaking at the rear out-put shaft of the tranny. as it turned out ( never knew it) the factory had a weep hole and the tranny fluid was leaking out of that spot. on level ground ....no problem. something to think about. i hate leaks so i'm w/ ya man!!

[junkyardjohn]

TRANS LEAKS ARE A REAL PAIN. I HAD A T-400 THAT LEAKED FOR ABOUT A YEAR BEFORE I FOUND & FIXED THE PROBLEM. IT WAS AROUND THE FILLER TUBE. FINALLY I HAD TO DRAIN ENOUGH FLUID OUT OF THE PAN, CLEAN ALL TRANS FLUID OFF THE MATING SURFACES WITH LAQUER THINNER, PUT SILICONE ON IT & LET IT SET UP OVERNIGHT BEFORE REFILLING THE TRANS. I WAS BEGINNING TO THINK I'D NEVER FIND THE PROBLEM OR FIX THE LEAK. JOHN

[skyhawk1]

I'm not a trans guy, don't know much about them at all, but mine leaked so much that I had to add a quart every 2 or 3 days! Looked like it was around the pan but it turned out that the leak was coming from the passenger side about 2 or 3 inches up. There's a round thingy (about the size of a soup can) that has a big O-ring on it. I believe there was a 7/16 head bolt that held it in. Anyway, took it out and went to a local hardware store and found another O-ring that would fit and put it back in. Havn't added trans fluid since.