I have replaced my rear main seal once now on a new motor I built this spring. It started leaking right after I got the motor running and I remembered shaving a TINY bit of one of the seals off when I put it in on the stand.

So I replaced it and used the little tool and didnt shave any of the seal - but now its leaking worse than before!!!

Is there some trick to putting in 2 peice rear main seals that I am missing here?

 

No, sounds like you did it the right way.

It's actually BETTER to be forced to do it that way, feeding the seal in endwise, than to just jam it straight in.

You should just loosen the other main bolts a bit to allow the crank some wiggle room. Use some motor oil or white lithium grease or similar on the seal, NOT sealer.

More likely, it's in backwards, such that the little grooves in the surface where it scrapes the crank, are wicking oil OUTWARDS, instead of INWARDS. Very common, very easy-to-make mistake.

Another VERY COMMON leak is between the bearing cap halves. There's oil pressure on the driver's side mating surface, and oil ABSOLUTELY WILL find its way between the metal surfaces, and especially right along the "corner" of the register cut, where the cap is chamfered. You should always put a very thin smear of sealer there, and a little extra in that corner; something that doesn't harden, like the Loctite/Permatex "thread sealer with Teflon".

 

Thanks for the good info.

 

Ok - going to do this again this weekend.

So I put oil on the seals before I put them in - no rtv on the ends where they would meet?

Crankshaft turns clockwise foreward looking aft at the motor - so make sure the groves face the right way.

Smear some white thread sealant on the machined bearing cap surfaces where they contact the block, especially around the oil feed hole and the edges of the cap.

Did I get everything?

Thanks.

 

Was the block line bored? If so there is a seal that is thicker on one side to compensate.

 

No - block wasnt line bored.

 

get the offset seal

the place where your seal was on the crank- it gets a little worn

sofa where ya been

missed you showing me the other side of the coin

 

Jamon,

I dont understand what you mean by "the place where your seal was on the crank- it gets a little worn"

And I already have a seal.

 

there is a seal that moves the portion that touches the crank about 1/4 inch away from where a stock seal would touch, its only required if that part of your crank is worn enough to make it leak. i put rtv on the half ends of my seal and installed it with a 1/2" offset. no leaks for me.

 

crank is brand new last year and looks fine.

 

just use the regular felpro blue seal then. part number BS40013

 

I put them in every block without silicon and they

NEVER

leak

period..........................................................

 

Jamon8 - thats great but thats what I did and I had a leak.