~98 gmc jimmy 4x4 2door 277k km's~

hey guys, was just told by my mechanic that my oil leak is coming from the rear engine crankshaft seal.

do they usually seep a little oil, not enough to really notice, then get larger and larger? or a 1 time deal?
if i go for a drive and let it get good an hot i can see it dripping a little above the drain plug area and the bellhousing on the tranny is crudded up and looks damp.

is this a serious job? im aware the transmission needs to come out, but other than that im clueless, searching here didnt yeild much for me.

my mechanic did a quick "unofficial" quote of 3 or 4 hours labour(maybe more?) plus a $35 dollar gasket, and a half hour labour to put it in. I think they said around $400. their shop rate is $65/hour

anyone have an idea how much labour should be involved? and is it a pretty common repair on these?

thanks

 

The engine pretty much needs to be pulled to change the rear main seal. If you pull one of the two rubber plugs that are located where the transmission bell housing meets the oil pan, you should be able to look up at the back of the block and front of the flex plate. If the flex plate is covered in oil, the seal is the problem.

If the flex plate is dry, the rear main seal is doing its job and the problem lies elsewhere. I have seen several cases where the oil pan bolts loosen up for some reason. I had this happen on my old '00 Bravada. I tightened the bolts down and it fixed the leak for about 3 months. Went back in and pulled each pan bolt (including the two located in the bell housing area itself) one at a time, cleaned the bolts and the threads in the block with brake cleaner, then put medium strength loctite on them. The problem never came back. I have since done this to a few other vehicles.

 

oh my! he didnt say anything about pulling the engine. and he seem'd pretty sure it was the seal. I mean, is it that hard to tell whether its the oil pan or the crank seal?

this is exactly what it says on my diagnostic print out. "The rear engine crankshaft seal is leaking and in order to repair it the transmission needs to come out" with no official price quote.

he mentioned he also owns a 96 or 97 blazer so im sure hes a little familiar with what needs to be done. So this is a very serious job then?

 

If he's planning on dropping the transmission, it is possible to change the seal although IMO, pulling the engine is a bit better.

But like I said, I have diagnosed MANY similar cases to yours and not a single one was the rear main seal.

 

I had the pan bolts and and rear main spring a leak on mine. The dealer repaired them under the extended warranty. $1,200 bill to the insurer.