Still weeps th350

[TJ1978]

so this is my third gasket, th350.
On my old C10’s the black neoprene worked well with a dash of Gasgacinch. Not working this time.
All was cleaned thoroughly with brake clean.

First was a no name torqued to 13 ft lbs, leaked.

Second, Tried the neoprene with some rtv, which I know isn’t recommend but I wanted to give it a shot, leaked. Torqued as well which ended up squeezing the gasket out.

Third: This one in the pics is one of those cork/neoprene types from summit. No sealant was used and I used a smaller ratchet, 1/4 inch to prevent over tightening. No torque, leaks.

The pan is stock and the bolt holes were chrcked for flattness each time. hough they were already flat, I gave a little tap for insurance.

As you can see it’s leaking pretty good. It had about 3.5 quarts in it as I type.

Im thinking just pulling it again and usuing permatex “the right stuff” and just ditching the gasket all together. I know the “right stuff” works. Downside, it can be a bitc$ for future removal, razor blade will be a must.

I have one of thise “chrome witha drain plug” pans from summit. Im thinking I may use that. But buying more ATF each time is costly.

Any advice?

Yes its been sitting for a couple weeks which can cause some seeping but. Just seeing if anyonr can offer anything?

I do know these things can leak from 9,000 different places but Im fairly certain its the pan. Or the pan being the biggest culprit.

 

[skunked]

skip the POS steel stamped pans and buy one with a machined flat surface.

 

[TJ1978]

skip the POS steel stamped pans and buy one with a machined flat surface.

This one is flat. None of those “humps” some aftermarkets have.

 

[dyeager535]

This one is flat. None of those “humps” some aftermarkets have.

I suspect the concern is the stamped steel not being rigid.

I had a pto cover on my 465 that refused to quit leaking (only after removing it once, never leaked prior). After multiple gaskets, and gaskets plus sealant, I took a bit off the bolt holes ID (something was a hair off), used RTV with no gasket, and let sit for 24 hours before use. Finally stopped the leak.

I hate leaks of any kind and will frustrate me to no end when I find them.

 

[TJ1978]

Was looking at this one;
https://www.summitracing.com/parts/lub-llt-g350/?tab=Overview


That moroso one and this are not cheap but if they seal it up, its cheaper in the long run. Opposed to $25 bucks in ATF each leaky gasket

 

[skunked]

This one is flat. None of those “humps” some aftermarkets have.

Aftermarket or OE, same issue with the stamped pans. I provided a link and a picture of the pan I used on my C10's TH350 your other thread.

Here ya go

I run the summit pan on my C10 without any issues https://www.summitracing.com/parts/sum-4338856

View attachment 319671

 

[TJ1978]

I suspect the concern is the stamped steel not being rigid.

I had a pto cover on my 465 that refused to quit leaking (only after removing it once, never leaked prior). After multiple gaskets, and gaskets plus sealant, I took a bit off the bolt holes ID (something was a hair off), used RTV with no gasket, and let sit for 24 hours before use. Finally stopped the leak.

I hate leaks of any kind and will frustrate me to no end when I find them.

Its driving me nuts. I already have to live with a tiny weep on my 350sbc. I want this darn th350 to be sealed.

 

[TJ1978]

Aftermarket or OE, same issue with the stamped pans. I provided a link and a picture of the pan I used on my C10's TH350 your other thread.

Here ya go

I have that one in the garage. I guess I need to drain and fill, yet again. Will the neoprene gasket suffice or should I try the “lube locker” gasket? I have 2 neoprene gaskets in my garage presently.

Sorry, I forgot about that other thread. Thanks for the link

Edit: this is the one in my garage, which is not the same as your linked pan. :https://www.amazon.com/Spectre-Perf...=2025&creative=165953&creativeASIN=B001DVTVZK

 

[skunked]

I have that one in the garage. I guess I need to drain and fill, yet again. Will the neoprene gasket suffice or should I try the “lube locker” gasket? I have 2 neoprene gaskets in my garage presently.

Sorry, I forgot about that other thread. Thanks for the link

Edit: this is one in my garage:https://www.amazon.com/Spectre-Perf...=2025&creative=165953&creativeASIN=B001DVTVZK

That's a steel pan, the one I linked is cast with a machined flat surface. You might get lucky and it seals but it's not worth the time and the added fluid cost IMO.

 

[76zimmer]

Lube locker and cast aluminum pan FTW!
And reuse the fluid if it’s new, get a paint strainer and reuse it.

 

[Wes Harden]

13ft pds is 156 inch pds. My normal is 25 to 30 inch pounds for this gasket.
Clean flat pan,heavy paper gasket touch of gasgacinch, torque to 30 inch pnds.

You sure it's the pan? Not shift shaft seal or cooler lines?

 

[skunked]

You sure it's the pan? Not shift shaft seal or cooler lines?

or the notorious kick down cable.

 

[TJ1978]

Ok,
Majority of the leak is from pan gasket and a minor from shifter shaft seal. And call me green, I dont know the name of this part but it appears to have a weep here, but that may be left over goop when I cleaned it before.

The gasket is stained red all the way around. Hell, it may just need to be tighter. I possibly babied it a bit too much on install.

Cooler lines are good and noticeable areas are dry.

 

[79rustyk10]

That's the cover for the governor.

 

[imiceman44]

That's the cover for the governor.

And it is leaking.
I saw it in the earlier pictures.
It might be the leak and running down the edge and look like the pan is leaking.
Happened to me.
Then the kick down cable started leaking

 

[wasted wages]

Easy to fix....pop off the bail clip, pull the cover off...clean the cover and replace the
o-ring...little bit of sealer...tap the cover back in place and reinstall the bail clip.

be careful the governor doesn't slide out with the cover off...

one more thing to check is the vent on top of the trans...if clogged, it can cause all kinds of havoc...leaking seals, blown out dipsticks, gasket leaks etc..

Edit: And for God's sake...toss the sheet metal pan!! get a good cast aluminum pan, new bolts and gasket. They seal 200% better and even stiffen up the case...
all good reasons to switch !!!

 

[thatK30guy]

Chalk another one for an aluminum deep pan. I try to swap these in anything I own. Stamped steel just doesn't quite do the job.

Use Vaseline on both sides of the gasket. Don't ask me but I've been told to use it and it's been a trick of the trade with tranny builders.

 

[diesel4me]

Make sure it isn't oozing out of the modulator where it enters the case,all it has is a o-ring and that forked clamp doesn't always push on it tightly enough to make a good seal..
Other places it can ooze fluid besides the pan is the shift shaft seal,the govenor cover (and yes,it does look like it is weeping there)--and the front pump seal..also if it was overfilled some,it may have peuked out of the vent up above and run down along the case..

I have glued the pan gasket to the pan with 3M weatherstrip adhesive or Permatex High Tack liquid ,then used grease or vaseline on the other side of the gasket to the transmission..this may allow you to take it off again in the future and not have to replace the gasket..and it usually doesn't leak...if the original pan was over torqued ,sometimes just tapping the bolt holes down with a backer under them solves the leak,but other times its too far warped to ever seal with a gasket alone..

 

[TJ1978]

will order a new pan and gasket today.

Any recommendations for tranny mounts? I may as well get it all done. Mine are soaked and cracked, very rubbery.

I searched here and online but came up empty on how to replace the transmission mounts.

 

[imiceman44]

will order a new pan and gasket today.

Any recommendations for tranny mounts? I may as well get it all done. Mine are soaked and cracked, very rubbery.

I searched here and online but came up empty on how to replace the transmission mounts.

Transmission mount is easy and if you still have stock motor mounts just get a stock replacement.
You unbolt the mount and lift the transmission and slide it off, put the new one in, start the bolts to make sure it is lined up and lower the transmission.
Tighten bolts.