rear main

hinoonaz · #1 (**permalink**) 03-18-2011, 08:05 AM

I have been chasing an oil leak for 3 years. Have ignored to long. Have tranny out again (3rd gear is a paper weight now). If i romove rear cap to put a small amount of silicone, should i lossen othe caps and retorque to spec or just the rear cap? I don't want to create any problems with crank and alignment issues.
thx gary

roadrod2000 · #2 (**permalink**) 03-18-2011, 09:05 AM

I just got done replacing the rear main seal in my 1970 302 block motor. the seal is easier to replace than I had anticipated. with the rear cap off you can slip a new seal into place on the top without loosening any other caps. Use plenty of oil on the new seal to help with the process.

hinoonaz · #3 (**permalink**) 03-18-2011, 09:23 AM

Its a later year 302, one piece rear seal. Replace rear seal once already and two pan gaskets without any luck. The rear cap seems to have a very slight relief on the outside edge. I am wondering if silicone or assembly seal of come sort is used when putting engine together? Can't seem to figure out problem. It is a puzzle.

MAStuart · #4 (**permalink**) 03-18-2011, 10:12 AM

Hi Rear main leaks are not always the problem . Rear oil galley plugs ,rear cam plugs ,intake manifold at the rear and runs down the back of the block . All the above can be mistaken for rear main leak. mark

bobcowan · #5 (**permalink**) 03-18-2011, 01:10 PM

If it is truly a RMS, there's no need to remove the cap at all. Simply pry out the old one, and put in a new one.

You can get a number of seals from Fel-Pro, etc. Most of them have a metal ring that seals around the bore. They can be a real bear to install straight; especially lying on your back. For those types of seals, it's better to loosen the main cap put in the seal with some silicone on the otside edge, and then torque down the cap.

Of course, once you loosen the cap, you'll have to remove it, clean off the old silicone, and then install with fresh silicone sealant between the cap and the block. If that's where it's really leaking, I would R&R the cap anyway, just to make sure it wasn't leaking at the cap.

If you remove the cap, there's no need to loosen the rest of them. Simply go back and forth and tighten the cap in stages.

I use the Ford motorsports seal - i can simply slide it in with my thiumb, and it never leaks.

hinoonaz · #6 (**permalink**) 03-18-2011, 09:08 PM

so far so good. ONe drop from the front of pan. Hope that is it. Put a steeda shifter on also. The stops should help. Feels good so far. Have put it thru 2 heat cycles. I know this subject has been beaten to death and I appreciate any info. The frustration on the oil leaks. thxs