Slight Leak

[pintopkp]

So I changed my transmission fluid on my 108 today. Everything seemed to be in order inside. Got the cover off, drained, cleaned the inside and the gasket surfaces, reinstalled new gasket, and filled her up with HyTran. However, now I have a *slight* leak that wasn't there before. Not too worried about it, but leads me to two questions:

1. Didn't use any gasket maker/RTV silicone with the gasket. Should I have?

2. What is the required torque of the cover bolts? Maybe I'm just tired, but I can't find a torque spec in the service manual. Not only that, but I'm just curious if my leak is because they're not torqued enough; but at the same time, I don't want to over-tighten them and cause any damage. They're pretty snug as they sit now.

Thanks.

[super1914]

Most likely your plate is slightly warped or there was something that wasn't cleaned up quite enough. You could try to add a little torque to the bolts but the torque spec is pretty low (20 lbs or less IIRC). If adding a little bit of torque doesnt work, you could pull the cover back off (with a clean pan to drain the hytran into) and put the plate on a peice of flat glass with metal sand paper and sand any highpoints out. Once it is flat, put on a new gasket and try it again. If it is way out of whack you can try an RTV type silicone, but I prefer to do it right.

[Matt G.]

3/8" grade 5 bolts in cast iron should be torqued to 30 ft-lbs according to the chart at the front of the service manual IIRC.

I have never used any gasket sealer-type products on the rear cover, but I think I will use some form-a-gasket next time. When I went through the rearend in my 1872, I cleaned it to near perfection, made sure the cover was flat, used new bolts and gasket, torqued to spec and...it leaves an ever-larger spot on the floor. I might have to drain out all the Hytran and try again...

[Yosemite Sam]

First thing:

If you didn't put the trailer hitch back on and did put the 3 longer bolts back in the bottom holes, they bottomed out in the holes and did not mash the cover tight up against the case.

Second thing:

If you used one of the longer bolts in the wrong place, you get the same result as in the "First thing" only in a hole other than the bottom three.

Might want to check that before you pull the cover back off.

If you did put one of the longer bolts in the wrong hole (or didn't put the hitch back on) and you tighten the bolts too tight... You will break that hole in the casting.

[pintopkp]

Originally Posted by Yosemite Sam

First thing:

If you didn't put the trailer hitch back on and did put the 3 longer bolts back in the bottom holes, they bottomed out in the holes and did not mash the cover tight up against the case.

Second thing:

If you used one of the longer bolts in the wrong place, you get the same result as in the "First thing" only in a hole other than the bottom three.

Might want to check that before you pull the cover back off.

If you did put one of the longer bolts in the wrong hole (or didn't put the hitch back on) and you tighten the bolts too tight... You will break that hole in the casting.

Nope, I got that part right thankfully; the three longer bolts are at the bottom. The more I think about it, the more I'm guessing that I didn't clean up the mating surfaces well enough. Everything else seems to work out. I'll just have to tear it down again and this time do a *super* good job and see how it goes; might as well check the cover for warpage too as Adam suggested. If all that fails, then I'll be joining Matt with the gasket maker.

Thanks, fellas. I'll let everyone know how I make out when I finally get a chance to do it.

[pintopkp]

Well looks like I'll be ok. Left it overnight and no more drops of Hytran on the piece of carbboard I put under it. I'm guessing what happened is when I filled the tranny to the plug, some it it ran out and down between the hitch and the plate. I'm guessing now that it wasn't leaking at all and what I was seeing was some of the oil that got stuck between the plate and the hitch.