Front and Rear Oil Seals

[Woody]

My 87 Gn is leaving a huge puddle of oil on the ground after a 11 mile trip to work everyday.................( I have to add a quart of oil every 4 days).........consequently I have stopped driving it until I can have the seals replaced.......My question: How much can I expect to pay to have them replaced???

Thanks guys!!!!

Woody

 

[Dan Thompson]

I think my rear seal was like $65 for labor plus the seal.

The flat rate at the shop I got for things like this is $65.

 

[JToups386]

I can't give you a price quote, because I've always done my own. The good thing is, you can do it yourself if you are accustomed to doing moderate mechanical work, and don't mind getting really freakin' dirty. It's not a clean job by any means, and will make you scream profanities from time to time. If money is not a huge issue, I'd pay a reputable shop to do it, but not just a blow-n-go type shop that may not be maticulous in their work. Find someone you trust, preferably a hot-rodder outfit.
The main thing I would advise is, DON'T use a replacement rope-type seal, as was originally installed from the factory. They are prone to leak immediately! I've had a mechanic tell me before, "the only way a 3.8 will not leak oil from the factory, is if it doesn't have any oil in it..." Fel-Pro makes nice neoprene replacement seals that work great and have prolonged life. If you need part numbers, I'll look them up for you. Email me or post a reply. Neoprene is the only way to go...!

 

[Gokou]

I'm looking to do the rear main on my TTA (started small, gets worse every time I drive it.) I had a discussion with John Pearcy a while back about this, and he said the Fel-Pro's were good for lower mileage motors, but he has had them leak on higher mileage motors, and his preference is for a Sabo (sp?) seal which he's had great luck with on motors of all mileage. He did say they are hard to come by though-- the only source he knew of was a Buick club back east somewhere.

Maybe someone else can chime in about which brand to go with... I only want to do this job once... lots more miserable in a TTA than in a GN.

 

[14mins]

What has to come off in order to replace the rear seal? I have leaks everywhere.

 

[Gokou]

There's a write up over at gnttype.org for how to change the rear main. No pics unfortunately, but a pretty good writeup.

 

[tc86gn]

Make sure that whoever does it uses a good RTV on the cap sides. Do not use the side seals that come with the rear main.
If they are used the chances of them leaking are pretty good.

 

[turbodave231]

For the rear main, I recommend the Fel Pro seal and I DO use the side seals. I have done at least a hundred of rear mains with very good results.

I use a loctite sealer on the cap surface and a dab of rtv in each side seal groove before pushing the side seal in place.

Whatever you do, Make sure the people who do your repair use the right parts. I would even go so far as to supply the parts to the guy doing the repair. Rope seals suck and you should avoid them like the plague!!

DR

 

[salvageV6]

I think it would be about 2 hours here in CT. Prolly $150- $160 for the complete job with parts. Had it done in the new GN.

If you know someone with a lift or pit I would definately do it myself. I don't so I paid.

SalvageV6 has a warranty replaced rope seal that has lasted 140K so far with minor drippage.

 

[Gokou]

So what's the verdict on the side seals? I get conflicting recommendations. Some say to use good RTV and fill the side cavaties, others say to use the side seals.

turbodave231: You say you like the side seals. Do you shoot some RTV up into the sides and lightly "paint" the side seals with RTV before you install them?

Also, on the rear main itself, do you "clock" it a little bit so the halves of the main aren't lined up with the cap/block seam?

 

[TurboDave]

After having replaced my rear main over 5 years and 40,000 miles back (it still doesn't leak). My recommendations are:

Clean everything up PERFECTLY!! especially before applying the RTV in the appropriate areas of the rear main.

I used the side seals, and the "nails" that came with them. I did however coat the outside of each side seal before inserting them!!!! VERY IMPORTANT, there can't be the slightest hint of oil on any surface you apply RTV to that you hope to seal.

Take your time and clean everything!!

Notice the theme??

I then ran a thin bead of RTV outward from the outer edge of the seal to the outward edge and down along where the side seals meet the block.

Kinda hard to describe, but basically just sealing the cap to the block as good as possible, but making sure NO RTV comes in direct contact with the crank journal, even after torqueing.


OH, almost forgot, make sure to let everything set up and dry at least 24 hours before firing anything up.

 

[tc86gn]

GOKOU,
No one answer is necessarily the absolute correct one. Usually on something like this,a lot of personal preference comes into play and you simply have to form your own opinion and then do it.
I couldn't make up my mind on this one either so I talked to Chris Conley and and took his advice which I have already posted.
Tom