Auto Trans Leak
Thread Starter
Drifting
Joined: Jun 2006
Posts: 1,327
Likes: 43
From: Vernon CT
Auto Trans Leak
So going through my new 1969 and one of the to-do's is to fix the automatic transmission leak. It was pretty bad. So I warmed the car up and tightened the bolts pretty good making sure not to over-tighten them.
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Last edited by 72and86; Apr 18, 2016 at 01:11 AM. Reason: sp
Advanced
Joined: Sep 2015
Posts: 89
Likes: 9
From: Dawsonville, Ga.
So going through my new 1969 and one of the to-do's is to fix the automatic transmission leak. It was pretty bad. So I warmed the car up and tightened the bolts pretty good making sure not to over-tighten them.
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Burning Brakes
Joined: Oct 2015
Posts: 781
Likes: 113
Grandpa used to tell us boys.."if you don't take the time and spend the money to do it right..
WHEN do you think you'll have either to do it properly and do it again..?Jim
Drifting
Joined: May 2006
Posts: 1,409
Likes: 136
From: PHOENIX, AZ Yes, it's true. You are a good woman. Then again, you may be the Antichrist.
So going through my new 1969 and one of the to-do's is to fix the automatic transmission leak. It was pretty bad. So I warmed the car up and tightened the bolts pretty good making sure not to over-tighten them.
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Now I swear the leak is worse. Maybe I did over-tighten them.
I would like to fix this ONCE so what's the best solution to approach this? Cork, Fel-Pro, RTV? A certain brand or type?
Thanks Steve
Oh well. That's a battle for another day. Good luck!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you DIY it, make certain that you tap/flatten any distortions on the face of the sheet metal pan rails. These usually get dimpled at the bolt hole areas. The pan must be flat if you want it to seal. The new trans filter kit will have a solid rubber seal in it. You can use it, or you can purchase a Fel-Pro composition (rubber AND cork) gasket for the pan.
With either, a light smear of Permatex gasket sealer (NOT silicone sealant
) on both sides of the gasket would be wise.
Flatten pan rails; wipe off pan and trans gasket surfaces, THEN wipe them again with lacquer thinner to get all oil off of them; put Permatex on one side of gasket and place that side on the trans pan; put Permatex on the other side of the gasket; install pan by first turning in bolts only finger-tight; then snug all bolts with small socket wrench; now, tighten all bolts to 1/2 of specified torque; finally, tighten the bolts to rated torque. You MUST do these steps if you want the gasket to seal.
With either, a light smear of Permatex gasket sealer (NOT silicone sealant
) on both sides of the gasket would be wise.Flatten pan rails; wipe off pan and trans gasket surfaces, THEN wipe them again with lacquer thinner to get all oil off of them; put Permatex on one side of gasket and place that side on the trans pan; put Permatex on the other side of the gasket; install pan by first turning in bolts only finger-tight; then snug all bolts with small socket wrench; now, tighten all bolts to 1/2 of specified torque; finally, tighten the bolts to rated torque. You MUST do these steps if you want the gasket to seal.
Racer
Joined: Aug 2013
Posts: 339
Likes: 54
From: Fayetteville NC
Same thing happened to me on my 72 TH400. I dropped the pan and cleaned the gasket surface with a fine scrubbing pad. Bought a tube of Permatex sealant (pep boys) made for transmissions. I sealed both sides of the rubber gasket and put the pan back together with the pan bolts hand tight. I let it dry over night and tightened the bolts nice and snug. Don't over torque the bolts where the gasket will squeeze out the sides. Filled with new fluid and no leaks. Oh, and I applied a little of the blue locktight since these bolts have a tendency of loosening up or backing out.
Instructor
Joined: Nov 2015
Posts: 195
Likes: 22
From: Ellenton, Florida
Auto trans leak
I had the same problem with my 78 Pace Car. A small dripping leak from the pan area. I figured that the PO of my car might have tightened the pan bolts too much, distorting them at the bolt holes. Sure enough, that had happened. Instead of trying to flatten the steel pan, I bought a cast aluminum finned pan with a drain plug and installed that along with a new filter and a FelPro gasket. Problem solved, no further leaks! Besides, the aluminum pan looks a lot better than the stock pan, helps with cooling because of the fins, and has the added advantage of a drain plug.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Burning Brakes
Joined: Sep 2009
Posts: 1,003
Likes: 48
From: hickory NC
C4 of Year Finalist (appearance mods) 2019
2017 C4 of Year Finalist
Loosen all the bolts, then slowly remove some of them to tilt the pan to get it to drain. Keep loosening and/or removing bolts until enough fluid is out to remove pan.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You can buy a bolt-in drain plug at NAPA. Just drill a hole in the pan and put it in. Just make sure that the drian plug is at a fairly low area of the pan AND that the stuff on the inside does not interfere with any of the valve body components. It won't allow you to drain all of the oil out; but it will let you drain over half of it, so that the rest won't slosh out when you remove the pan. And, it's only a few buck$ !!