Rear main seal replacement question.

[granitestategn]

I told an old motorhead at work that I needed to change my rear main seal because it leaks so bad. He said while I've got the pan off I should change my main bearings, too. I'm of the opinion that "if it ain't broke, don't fix it". I see opportunities to really screw something up. My car has about 97K on the clock and has had Mobil 1 in it since the second oil change. The motor doesn't knock (except from too much boost). He (motorhead) says the rear main leaks because the main bearings are gone. I say horsehockey! I think it leaks because it's and old, dried up rope packing seal. What say you, oh Turbo Gods? :anbet:

[Sixgun86gn]

Forget this guy.The rear seal blows from getting old or crankcase pressure.I wiuld not worry about it if you haven't had alot of metal in your oil.Just my.02.

[HairDrier]

On SBC Chevys and Fords changing the rods and mains is a piece of cake and is often done because it is cheap. A SBC with new rods and mains and a new oil pumps will often go 250000-300000 miles till they have no compression.

Our engines have very different tolerances and oiling systems, so dont piss with it. You can put a new oil pump in if you want.

[Recklessrob]

Gregg,
I wouldn't lose too much sleep over it. My GN has 168k
on it, and the seal was leaking for years. Ironicaly after driving it
a bit, it stopped leaking on its own (yes, there is still oil in it! :-) )
I'd still replace the seal anyway. While you're there, its easy to check the bearings. With the rear seal and sides removed you can plastigauge
the rear main bearing since you'll have it out anyway. I'd also check
crankshaft endplay, to make sure the thrust bearing is ok. I've
killed more than my share of thrusts over the years. :susel:
If you have any questions or would like help, I live in Derry also.

[weeee_6]

He (motorhead) says the rear main leaks because the main bearings are gone. I say horsehockey! :anbet:

I replaced mine this summer. I suspected that mine leaked because 3/4 of it was stuck to the bottom pf the oil pick-up, and not that the bearings were gone. FWIW

Bob

[SuperSix]

He's bonkers.

Unless you have a metal in the pan, low oil pressure, or it knocks, just replace the rear main, following the instructions HERE (http://www.gnttype.org/techarea/engine/rearmain.html).

:deal:

[87natty]

The only thing I regrte about doing my rear main was not taking the time to do the front seal. Clean out your oil pickup too.

[SuperSix]

The only thing I regrte about doing my rear main was not taking the time to do the front seal. Clean out your oil pickup too.

THat's a whole different job.. That's best done when replacing the timing chain. :D

[granitestategn]

Thanks for the quick replies. I kinda figured he was full of it. Nice guy but doesn't know turbo Buicks. I will probably do the front seal because I will be doing the timing chain, cam button, water pump, valve springs and a new oil pick-up tube and screen at the same time. That means I should have it back on the road by ......next December. :albert: Probably put the Hooker exhaust on it too. I need to get the parts out of the garage and on the car. Thanks Recklessrob for the offer to help. I'm in Hampstead. Stones throw from you. I'll give you a call when I get a chance to dig into it. I'll supply the beer......lots of it. :beerglass