turn1racing

I replaced the rear main seal (2-Piece/Part 2912 from Fel-Pro) and pan gasket on my 305 small block chevy in an attempt to fix a leak, however, the new seal leaks worse than the old seal. My concern is that while it's possible I made a rookie mistake and screwed up the install, I don't want to invest more time and money into replacing it again the leak is being caused by crank shaft wear/damage and not something I did wrong because this engine is only a temporary holdover while I work on getting a new one ready.

This engine has seen a lot abuse in it's previous life. There was a significant amount of sand in the oil pan and there was gunk and carbonized oil in the lifter valley and valve covers (from infrequent oil changes I'm guessing). I had to replace the cam due to several lobe failures and mushroomed lifters.

The crank itself had a visible groove worn into it where the front of the old seal was making contact. Based on my limited experience, the bearing looked worn but useable. Is it possible this wear is preventing the new seal from working?

On the other hand, this is the first time I've done this job and while I did following all the instructions on the packaging, it wouldn't surprise me if I made a rookie mistake. Without pulling the engine and pan to inspect it, what could be some likely culprits?

sofakingdom

iTrader: (1)

Not putting sealer on the mating surfaces of the cap & block on the driver's side.



Observe that pressurized oil passes from the oil pump, into the cap, through passages drilled through the cap, across that gap, and into the block. Without a thin schmear of sealer on the cap, there is a direct leak from pressurized oil to the outside world.

turn1racing

I did put a thin layer of RTV sealer on both the driver and passenger mating surfaces.

sofakingdom

iTrader: (1)

Oh well... It's too dark out for me to look up in there right now and see what you did wrong, best I could do was guess, and that's not very good.

UltRoadWarrior9

2 piece RMS was made to leak sorry.
A friend had me over to help with a Jeep 4.0 straight 6 RMS. Same 2 piece design. We used sealant where the 2 halves come together. POS still seeped oil. A real shame. It's an old pathetic design.

NoEmissions84TA

iTrader: (1)

1) You could have installed the seal backwards. The lips point towards the front of the engine.
2) The seal should be offset about a 1/4" in the cap and block. That way, all the parting lines do not line up.
3) RTV sealer in the corners of the rear main cap. Thread sealant on the back 2 oil pan bolts.
4) Did you use that 1 piece FelPro oil pan gasket? Everyone else has no leaks - not me.

UltRoadWarrior9

2 very good points there... Regarding my install on former post, since it wasn't my car, I didn't even think of offsetting the seals. Attention to detail always critical.