Rear main seal

[Redneck86]

Is the rear main seal for a 86 351W a 1 or 2 piece? It leaks a little, im gonna have the transmission out to put a better torque converter in it so ill go ahead and replace the rear main while in at it.

 

[BLADE262US]

A 1986 should have a 2 peice rear main . They are very hard if not impossible to change without dropping the crank down . Not alot of fun /emoticons/[email protected] 2x" width="20" height="20" />

 

[Redneck86]

You mean i gotta take the crank out to change it?

 

[BLADE262US]

Yeah pretty much the originals were like a rope seal and there is a steel pointed pin in the Upper half so the seal couldnt turn . You have to get the crank down far enough to get the seal off that pin .The new ones are rubber with a steel insert so you almost have to get that pin out or it will distort the seal . The 1 piece main seal is alot easier to change /emoticons/[email protected] 2x" width="20" height="20" />

 

[Redneck86]

Well damn, i might as well rebuild the engine if i gotta do all that. Could i just order one of those rebuild kits from Summit and put that in there, or do i need to bore .30 over? The kit im lookin at comes with flat top pistons and everyting to rebuild the engine, i was plannin to put a mild camshaft and timin chain from Comp Cams also.

Heres a link to the rebuild kit

Summit Racing-Federal Mogul Premium Engine Rebuild Kit

 

[Broncobill78]

Well damn, i might as well rebuild the engine if i gotta do all that. Could i just order one of those rebuild kits from Summit and put that in there, or do i need to bore .30 over? The kit im lookin at comes with flat top pistons and everyting to rebuild the engine, i was plannin to put a mild camshaft and timin chain from Comp Cams also.
Heres a link to the rebuild kit

Summit Racing-Federal Mogul Premium Engine Rebuild Kit

I've replaced it before in a 460 and while difficult it's not impossible. You have to loosen each of the mains a bit until the rear drops enuf to let you snake the seal out, but that only works with a 2-piece and you still need to drop the tranny to do it (with an auto anyways)

However, I have an 88' and not an 86' so I can't be sure but the 88' factory manuals say that it's a 1 piece seal and gives the following procedure for replacing it *without* pulling the engine (that is as long as you're just replacing the seal and not the bearing as well). Start w/page 002 & then go to page 001, sorry, my bad when scanning. Start on 002 at the very bottom of the right-hand column, right where it says that the engine uses a one-piece rear-main.

As always, I'm no oracle so take anything *I* have to say w/a grain of salt