Transmission Plate bolt torque

[aj81spider]

I was preparing to bolt my rebuilt transmission to my rebuilt engine when I noticed the transmission was leaking along the edge of the plate bolted to the bottom (the one with the drain plug in it). The bolts were fairly loose, so I looked up the torque value. I apparently did not look in the right place. I thought the value was 18 ft/lbs - it clearly wasn't. The first bolt I tried to torque to that value snapped off. I was fortunately able to get the broken bolt out, but am now left with the question:

What should the bolts that hold the plate on be torqued to?

While on the topic - should gasket sealer be used (what kind?) and if so should it be applied to both sides of the gasket? It looks like the rebuilder used gasket sealer, but only on the transmission side of the gasket.

Thanks for any insight you can provide.

[Exit98]

AJ,

I have no idea what the torque rating of those bolts is. I just finished a similar job. I got a new gasket from AR, set a bead of that blue sealer, and snugged the bolts (10mm?) up. Bolts like that I think you can just do by feel. When I'm under the car doing what ever a couple months from now I'll make sure they're still snug, I do the oil pan bolts the same whenever I change the oil.

Good luck.

[aj81spider]

Thanks Doug,

Did you do the blue sealer on both sides of the gasket or just one (and which)?

[seabeelt]

When I did mine, I put it on the pan side of the gasket to help compensate for the small deformation around the bolt holes
R/

[Exit98]

Pretty sure I put the sealer on the trans side of the gasket.

Don't overthink it. It's not a safety issue, you just don't want it to leak.

[vandor]

The pan usually mushrooms out around the boltholes. I usually lay a ball peen hammer on the top and hit it with another hammer to make it flat again. You can then lay the pan against the trans case without the gaskets to see if there are any high spots.
In most cases I do not use any sealer, but on this gasket I put on some aviation permatex. It's a sticky glue kind of sealer.

[aj81spider]

Thanks for the suggestions - I will try them out this weekend. The hammer suggestion is good - the pan doesn't really look that level right now.

[majicwrench]

Silicone sealer should not be used on a gasket. Gasket should seal without anythign else. The aviation sealer is good stuff if you really feel you must use sealer.
Torque on a 6mm bolt like that is 48 in-lb according to my chart. That aint very tight.
Keith

[aj81spider]

One question: I found Aviation Permatex and there appears to be at least two types. Did you use #2 or #3?

[aj81spider]

Well I put the pan on with a new (paper) gasket and Permatex (#3) on all surfaces per the Permatex instructions. Went out tonight to find a big puddle under the transmission. It looks like it is leaking only along the back edge...argh.

I pulled the plate off my spare transmission and ordered a neoprene gasket this time. Hopefully one or the other of those two strategies will seal it up. Thankfully the transmission is out of the car so it's easy to work on.

[majicwrench]

If the pan is flat and the trans case is flat and you have a gasket in there pretty hard for it to leak. Gobs of sealer can cause issues. Look forward to your fix.
Keith

[aj81spider]

OK - I'm probably jinxing myself and will find a big pool of oil beneath the transmission tomorrow morning - however:

The neoprene gasket was thinner than the paper gasket and was folded up in the envelope it got delivered in. It didn't look like it would be a better seal than the paper gasket at all, so I chalked it up to a bad purchase and used another paper gasket. I cleaned up and painted the plate from my spare transmission and put a thin coat of aviation permatex on both sides of the gasket, the transmission, and the plate (per the instructions on the permatex). I tightened the bolts down to a firm but not excessive amount and let it dry two nights.

Yesterday I put a little GL-1 in it to see if it would leak (not wanting to have to empty out a pint and 3/4 if it did). This morning no leaks; tonight no leaks. I filled it the rest of the way tonight and am keeping my fingers crossed that it is sealed!

Big family party this weekend, so it will be a couple of weekends before I get the transmission bolted to the engine and re-installed in the car.