Undertightened cork gasket on TH350 and whole thing flooded, clean and reuse?

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dkraven

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Previously used a Moroso metal core gasket with a new steel pan and overtightened it. Decided to try a Mahle metal core cork one instead as I read cork is more forgiving. Took the time to hammer down the bolt holes and flatten the steel pan and then unfortunately was gunshy about tightening the bolts. As soon as I put new ATF in the entire seam started pouring out fluid.

My question is, is that cork gasket ruined now or can I clean everything up, install it again with a bit more torque, and try again?
 

PrairieDrifter

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I hate cork gaskets. My 2 cents. I don't run cork so I don't really know but you should be able to clean it up. It'll end up leaking anyways!
 

TotalyHucked

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^Agreed, I hate cork as well. Every T350 I've worked on, we used a metal core gasket and put RTV on both sides.
 

legopnuematic

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I’ve gone to using LubeLockers on my transmission pans and diff covers and so far I like them. More costly than other gaskets but they are reusable and made in the USA.
 

squaredeal91

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I've had cork gasket problems on a 400.
What I did was a thin layer of Trans rtv on both sides and let it sit a few minutes then tightened. Stopped its drip issue.
 

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Over tightening can warp the pan, too, good thing you under tightened instead of the former. It's a very low torque spec on the pan bolts, I think 12 ft/lb.
 

Kheughens

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I used both cork and rubber gasket but still had small leak issues (possibly pan slightly bent). I friend told me to ditch the gasket and just use permatext without the gasket. Worked flawlessly! No leaks! And cheaper.
 

bft305

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I have used both and they all leaked, tried flattening it out and no luck. Finally just used a silicone gasket and transmission gasket maker on both sides and no leaks yet.
 

DoubleDingo

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I used both cork and rubber gasket but still had small leak issues (possibly pan slightly bent). I friend told me to ditch the gasket and just use permatext without the gasket. Worked flawlessly! No leaks! And cheaper.
Not recommended, but if your pan is bent and can't be straightened, this is an alternative.
 

tenthirtytwo

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The only time that I use a cork gasket is on an overhaul, meaning that everything is bone dry after a rebuild. On a trans service (fluid change) I'd only use the fiber/composite gaskets. It's been my experience that it's impossible to drain all of the fluid on a service. The residual fluid dripping from the trans will wet the cork gasket in ATF. Tightening the ATF saturated cork gasket almost always squishes the cork out as you tighten the pan bolts.
Edit: Someone mentioned flattening the pan. Sometimes the bolt holes in the pan need to be hammered down a bit. They can get a raised dimple around the bolt holes from over-tightening. You can set the edge of the pain on the edge of a bench, tap the pan rail (the surface that mates to the transmission case) at the bolt holes down flat with the pan rail.
 
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tenthirtytwo

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Previously used a Moroso metal core gasket with a new steel pan and overtightened it. Decided to try a Mahle metal core cork one instead as I read cork is more forgiving. Took the time to hammer down the bolt holes and flatten the steel pan and then unfortunately was gunshy about tightening the bolts. As soon as I put new ATF in the entire seam started pouring out fluid.

My question is, is that cork gasket ruined now or can I clean everything up, install it again with a bit more torque, and try again?
IMO, once the cork gasket gets saturated with ATF, it's unusable..
 

dkraven

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Update. Spent a good deal of time flattening the pan and hammering down the bolt holes. Reinstalled the pan with the Moroso metal core gasket and tightened them incrementally and staggered to 6.5 foot pounds. (Moroso emailed me and said to tighten between 80-90 inch pounds, so I figured 6.5 foot pounds was fine). Two weeks later and no leaks! Thanks all for the help.
 

DoubleDingo

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Glad it worked out
 

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