Hello Guys, Well, the new rebuild is running fine, but like I mentioned in my previous posts, there is a bit of an oil leak out the back of the pan...at least I'm 99% certain it is the pan seal. However, my question relates to the rear main seal--On the two-piece seal, rubber version, is there supposed to be any sealant applied between the two halves, or on the cap-to-block face? Thanks! ...... ....By the way-unrelated- does anyone know where I can find the transmission shifter shaft seals for the 2.77? (The seals that keep the transmission oil from coming out onto the shifting linkage)
Rear Main Seal
- Thread starter adamscm
- Start date
Yes on the sealer! Its common practice to rotate the upper and lower halves of the seal so the parting line of the block and cap is offset from the parting line of the seal halves to reduce the chance of leaks. Apply a thin dab of sealer at the parting lines of the seal and this should also seal the parting line of the block and cap once in place.
The seal ends should be at 10:00 & 4:00 not flush with the cap & block. I use gray permatex on each ends of the seal. You should run a very small bead at the both sides of the block where the rear main cap fits & a very tiny small amount from the seal to the edge where the cap fits onto the block.
Did you put sealant on the flywheel-flexplate bolts to the crank flange??
Did you put sealant on the flywheel-flexplate bolts to the crank flange??
Yes, I did seal the flywheel bolts. Like I mentioned, fingers crossed, I think it's the pan seal. I was tempted, though, to pull the rear main cap off while I'm under there to see if the rebuilder offset the seal and if he used any sealant. I've actually got an extra seal left over, and I could replace the bottom half if I wanted to after inspecting it.......by the way---I've never seen one, but does anyone make a ONE piece pan gasket, or are we stuck with the cork sides/rubber ends? ........also, I found the answer to part II of my questions above....believe it or not, you can still get Trans seals from OReilley's!.........
This weekend, I put on a new pan gasket. While off, I did take the rear main cap off. The builder not only didn't offset the seals, but used no sealer as described above. So I replaced the lower main seal and did the little dabs of sealer. So far, no leaks. Question: The bottom half of the seal easily slid around in its groove. When assembled, does the pressure (I'm guessing) keep the seal from spinning? I know with the old rope seals, there is a pin that holds it, but not so with rubber.
X2 yes when assembled correctly (seal offset) and main cap bolts torqued to spec that seal isn't going to move. Good luck 
Thanks----Still no leaking! I used a light coating of Permatex (#3?) between the block and pan gasket, mostly to make the gasket stick to the bottom of the block. Then I used Black silicone between the gasket and pan, and on the ends. Like I've mentioned before, I think the leak was from the pan, but I feel more comfortable anyway with the rear main seal now.
glad to hear it's not leaking so far. Was the oil pans rails nice and flat when you had it off? Good luck on the repair 
