so i bought my 98 Sonoma around 2 weeks ago and it didn't have much of a leak at the time. Maybe a drop or two but it didn't bother me because it has 126k on the motor so some leaking was expected but now its like oil is leaking out like crazy after i drive. In the matter of maybe an hour of having the car parked it would leave a ft long puddle. I'm thinking its the rear main seal because its dropping down from between the tranny and motor. my question is, how big of a project would it be to replace this?
I have some experience in engine work like changing my timing belt and water pump, etc. But I've never done something where i had to pull the motor off the tranny and maybe out of the car. I live near a couple old car enthusiast that would have no problem helping me if i got stuck. My main concern though is that this is my daily driver and if it takes me more than a weekend i have no ride to work, school, etc.
Any help is appreciated

 

I would first rule out a leak elsewhere. Look down the back of the motor with a flashlight and see if there is any oil leaking higher than the rear main seal. I have seen a real bad valve cover leaking from the back that the owner swore was a rear main. I believe on your motor the oil pressure sender may be back there too (not 100% sure though). I would not want to do a rear main in my driveway! A local shop with a lift will be able to knock that job out in a day. The last one I had done in a 2001 2500HD w/ a 6.0 was done in about 5 hours. Also I HIGHLY recommend any time the motor and trans are separated to do the front seal in the transmission as well. The part is cheap and the labor is already done. Good luck with it man!

 

cool ill check today, thanks man

 

I checked out the back of the engine but didnt really see much oil coming from the valve cover.
But also forgot to mention something, every time i finish driving there is a noticeable smell of burning oil and burning clutch. At first I was like oh well maybe im just not used to the heavier clutch of a truck or something but now its like im really trying and yet my clutch will still get cooked. Doesn't slip but burns.
What it might be is that oil is getting on my clutch because of the rear seal and that is causing the burning oil smell and possibly the burning clutch smell.
Talked to my mechanic and he gave me a price of 400 in labor to change the rear seal and the tranny seal. My buddy told me I might as well also just get the clutch changed since he's down there. I mean it doesn't slip but at 126k on it it might just start pretty soon.

 

Thats not a bad price...I hope it works out for you!!!! Make sure you ask your mechanic if there are any other things back there that could be leaking or need to be replaced while the trans is out. I had a rear main on a 6.0 replaced. I paid this guy $350 to do it and come to find out on the 6.0's there is a main seal, cam seal, and a metal gasket back there that should always be change together. This idiot didn't know about that and guess what...it was the metal gasket that was leaking. So $350 later I still had a small drip in the driveway. Talk about pissed!

 

**** that really sucks :-/ yeah one of the reasons i like to try and do things myself but in cases like these I do have this mechanic that i trust pretty well, can only understand every other word he says... but still a real good mechanic. im gonna look around and do some research maybe there is a whole kit including all the seals and gaskets that can be changed in that area.

 

well we took another look and it actually did turn out to be the valve cover gasket. The was it had a leak in the vary back of the cover and only leaked when i hit the gas giving it pressure. So what we did was left the check/fill cap out a little to free it of some pressure.
This weekend when i have will probably when I change the gasket, so just curious if there is anything i should know before i start this? This is my first time under doing work under the hood with this truck so I'm not yet familiar with everything.