rear main seal

i just bought a 91 z28 with 305, and the rear main seal needs changed. how hard is it to change and what do i need to do it? thanks

Well sorry to tell you but unless you like pulling transmissions it kind of hard. For a rear wheel drive car it would be easiest to pull the trans to get to the back of the crankshaft. But don't get bent out of shape yet. If it's not leaking that bad you could try to find some oil additives that cause rubber to swell and it might make it quit if it's only a small leak and/or you could try heavier oil like 50 weight. But other than that you'll have a little project on your hands.

I know with 4th gens, and I guess 3rd gens this is like the annoying little kid that will never go away. As long as the leak isnt TOO bad.. just gotta live with it, I know people who have replaced theirs 4, 5 times and it keeps leaking again

I know with 4th gens, and I guess 3rd gens this is like the annoying little kid that will never go away. As long as the leak isnt TOO bad.. just gotta live with it, I know people who have replaced theirs 4, 5 times and it keeps leaking again

Replaced 4 or 5 times. That would be a pain. I hope nobody else has to do that.

Leaking rear main seal
+
blowing oil at startup out exhaust from bad valve guides

= Small block chevy.

Welcome to the club.

Leaking rear main seal
+
blowing oil at startup out exhaust from bad valve guides

= Small block chevy.

Welcome to the club.

lol... That happened to my 69 Olds 350. But it has about 180,000 miles on it and has been run hard. I pulled it and it is about to get a full rebuild and get dropped into an 85 Cutlass Supreme, a little old ladys car. Then the 69 Cutlass is getting a 455.

85 Cutlass Supreme, a little old ladys car.

nice, love the simplicity of those cars, cutlass and monte, the regal too, but it had a little more flash to it.

nice, love the simplicity of those cars, cutlass and monte, the regal too, but it had a little more flash to it.

It is going to be real nice. There are so many ricers around where I live and I'm fed up. Them with their fart cannons and neons thinking they are fast. When I pull up to them with a 85 Cutlass they'll probably laugh or something (I hope). It only has 14 inch tires which are something like 10 inches wide. It's just going to smoke those little tires until they pop. I'm going to love evey minute of it.

yeah I was getting at they carry the near ultimate sleeper approach, cause almost any damn thing can fit inbetween the fenders.

I just have to pull the extremely tired 3.8 out and drop in the 350. It has 2.14 gears in the weak rear. What should I do drive it until it breaks or just put a nice sturdy 3.73 or 4.11 gear rear in?

err, yeah, ditch the aspercream fetching 2.14 (holy crap they made em that small?).

Withc a SBC calling the shots, it won't be too long before ithe stock rear calls it quits.

yea I was planning on getting 3.73 but it's not a SBC. I've seen many of them and this is an Olds 350. I'm pretty sure it's a BBO 350.

but it's not a SBC. I've seen many of them and this is an Olds 350.

My bad, either way a hell of a change in store for that car. Hell even getting a 3.23 under it would help, little more common to find anyways.