I need some tips and tricks for getting a trans pan gasket to seal

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firebane

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This damn truck can kiss the fattest part of my ass. Looks like I'll try nothing but adhesive tomorrow. I am not happy at the moment.

Are you sure the transmission flange is square? Have you taken a straight edge to it? Did you apply a bit of rtv to the threads?
 

CSFJ

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The flange on the trans itself? or the pan? Installed a new pan, smeared some adhesive on the pan flange, installed gasket to the pan, flipped over on a flat level surface, applied light pressure to set the gasket into adhesive evenly. let set for 30 min or so while I swapped out the tv cable, and let everything drip off underneath. I used blue thread lock on the bolts. should I have used sealant on those too?
 

CSFJ

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And I used a 1/4 drive ratchet with a 6 in extension to tighten them with
 

firebane

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The surfaces on the train are they flat? Lay a straight edge along the surface and check.

I have never used lock tight on the bolts but I have used rtv on the threads.

Maybe you need a new gasket?
 

CSFJ

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The gasket was new too. The flange on the trans itself were smooth, didn't think to check for level. I'll try the rtv on the bolts tonight, maybe I'll get lucky.
 

CSFJ

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Well,I dropped the pan again and applied rtv to the trans side of the gasket.The pan side appeared to be sealed to the pan pretty good, so I reinstalled with the rtv on the gasket and the bolts. It's setting up now. see what happens tomorrow.
 

kleedus

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throw the rubber gasket in the trash and get a cork one I get them from napa

clean the sealing surfaces real good make sure the pan is not warped put back together with NO silicone or sealer of any kind. just the clean dry cork gasket and do not over tighten the bolts. a aluminum pan helps a lot it will not flex like a sheet metal pan will
 

CSFJ

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throw the rubber gasket in the trash and get a cork one I get them from napa

clean the sealing surfaces real good make sure the pan is not warped put back together with NO silicone or sealer of any kind. just the clean dry cork gasket and do not over tighten the bolts. a aluminum pan helps a lot it will not flex like a sheet metal pan will

If it still drips tomorrow, that's probably what I'll do. The gasket that's on it now is a fel-pro fibroid or fibrous or something. It's not cork, but it's not rubber either. It felt like it would do a decent job, but who knows. Like I said, tomorrow if it still leaks, it's back to cork or all rtv.
 

CSFJ

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And the rubber gasket that went on when I did the filter hit the trash can this afternoon.
 

firebane

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For my TH350 I used a FelPro TOS18633. Its not cork or rubber its some weird material and I haven't any issues with mine.
 

CSFJ

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For my TH350 I used a FelPro TOS18633. Its not cork or rubber its some weird material and I haven't any issues with mine.

I think that's the one I have now. I've got rtv on both sides now. Just gonna let it set up overnight.
 

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Im with Kleedus forget about all that goo junk. If the pans flat and the transmission is flat it wont matter cork or rubber just make sure everything is squeaky clean! You don't need any goo on the gasket or mating surfaces or bolts!

The proper toque specs is 10 ft lbs just looked it up!

I don't know what to tell you. I have done this more times than I can remember and never once had a leaker except once when the pan was bent.
 

CSFJ

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That's what makes this so damn infuriating. I know I shouldn't need any sealant. I know the torque spec is 120 in. lbs. While I'm not in possession of a torque wrench rated for that small a number, I'm pretty sure the short 1/4 drive ratchet with a long extension that I used limited the amount of torque I could apply. I hate stupid problems like this. The original pan doesn't appear bent, and the new one that's on now certainly isn't, can't see or feel any gouging or damage on the flange of the trans itself either. I haven't added any fluid yet this morning, need to run a couple of errands before I get to it. I'll report back with the results in a bit.
 

CSFJ

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I'm cautiously optimistic that the damn thing thing might not drip this time. added fluid, drove it to the corner and back (2 miles) and left it idling for 30-40 minutes. no fresh spots under it. I'll be running it this afternoon so we'll see how it does.
 

CSFJ

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spoke too soon. just walked outside to get in and saw the fresh puddle underneath. Is it really asking that much to get this bastard to seal? And why would it only drip after it was shut off for a while? and not when it was up to temp and running?
 

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