changing engine seals/gaskets

[3XBrownCutty]

Engine: 3.8 V6

My oil pan gasket is in pretty bad shape and will need replaced soon along with the rear main seal. My question is, are those able to be changed without taling the motor completely out, maybe just lifting it up a little bit?
I have access to a cherry picker. Does anyone have experience in doing these things?

 

[85 Cutlass Brougham]

The rear main seal is a PITA. You will need to pull the oil pan and rear main cap to access it. Just be sure to use a rubber seal and NOT a rope seal this time around. You may have to remove the transmission for better access, but you may get away with lifting the engine enough to slip the pan out. If not and it hits the flexplate, plan on pulling the trans and flexplate too.

 

[3XBrownCutty]

The rear main seal is pretty easy to get to and straight forward to replace then? does the pan have to come all the way out to get to the rear main seal?

Just wondering because the oil pan is way worse, and I might end up just doing the pan gasket instead of getting into a situation where i don't know exactly what I'm doing.

 

[85 Cutlass Brougham]

The pan has to come all the way out to get to the rear main. Remember that you need to be able to put a torque wrench on the rear main cap when you put it back together, and you don't want to strip the bolt head. It's not an easy job as it will take quite a bit of time to do it. If it had a 1 piece rear seal, you could do it just by removing the transmission and flexplate then replacing the grease seal.

 

[Uncletruck]

Not sure if we are referring to a Chevy 3.8 (229) or Buick 3.8 (231)? If it's in a Cutlass I'll take it on a guess that it's the Buick engine.

The oil pan will come off the Buick 3.8 without lifting the engine or removing the transmission. However, the crossover pipe MUST be removed from the exhaust manifolds and catalytic convertor to have working room, which might entail having to cut the bolts (right side) and nuts (left side, and you might need to press new studs in.)

Here is an excellent procedure for doing the two piece rubber seal (instead of the rope seal) on the Buick 3.8. (Although this site refers to turbo 3.8's, the N/A is the same process just a thinner seal.) As this site states, DO NOT use the rubber side pieces for the bearing cap. They will no doubt leak, I learned this by trial and error.

http://www.gnttype.org/techarea/engine/rearmain.html

-UT-

 

[3XBrownCutty]

Thanks UT!! I guess I'll wait to do this until the next time I change oil then.

One last question, can I put any kind of sealer or RTV on the pan gasket, or will that "contaminate" the oil.

UT: I just realized that you are in the Erie area as well. Maybe I'll see you cruizin' around in that pontiac of yours. Its cool to see people on the site close to home.

 

[Uncletruck]

The pan gasket is cork, you can use the same RTV you use to fill the main bearing cavities with to tack the gasket in place on the pan before you re-install it to the engine.

I did one thing with the rear seal differently. I did stagger the pieces as mentioned on the turbo Regal site, but in addition I put a small dot of super glue on the ends of the seal before I installed and torqued the main cap. As I did this job nice because I did it twice, the first time around I did notice some leakage from the first seal I put in. (That in addition to leakage from the side pieces I was stupid enough to use.) The second time around, it has remained bone dry. You really have to take your time with the rear seal and give the RTV time to set up, I would let it sit overnight after filling the cavities before putting the pan back on.

-UT-

 

[3XBrownCutty]

Thanks for the pointers! This will really help my dad and I, because he hasn't replaced a rear seal either.