front oil seal

Hey getting ready to do work on my friends 96 blazer.He purchased a rebuilt motor from Advanced auto a while back but his front oil seal has failed. It on the timming cover is this a common failuer. Just wanting to know. I know its easy to replace. Just wanting info. Thanks.Gary

Just make sure that is where the leak is coming from.

Did he replace the plastic timing cover when he installed the new engine?

The motor came with a new timming cover. Plastic.. We also did some checking after I left this forum. I looked up and found timming covers are a common oil leak problem. So went back and doubled checked and there it was bottom, it leaks so bad over time it was getting kicked back up looking like the oil seal area. It was all over his crank sensor.I pulled the codes with my scanner and got a 340 and 304 code I am sure the oil is one of the problems.Sence its not the seal,Im going to change the gasket on the timming cover. I notice there is no bolts at the bottom.Still looks to be an easy job though. Ill search some more but if you have any more input let me know. Thanks,Gary

On the subject, I'm in the middle of replacing a water pump and was wondering if I might as well go ahead and replace the timing chain and gears while I've got easy access. My truck has 155000 miles, and there is a small leak out the front seal anyway. What do you guys think? Is there much chance that the timing chain and gears need to be replaced (anyone ever hear of them failing on the 4.3)? Would I be better off leaving it alone since the leak isn't that bad?

On the subject, I'm in the middle of replacing a water pump and was wondering if I might as well go ahead and replace the timing chain and gears while I've got easy access. My truck has 155000 miles, and there is a small leak out the front seal anyway. What do you guys think? Is there much chance that the timing chain and gears need to be replaced (anyone ever hear of them failing on the 4.3)? Would I be better off leaving it alone since the leak isn't that bad?
Always would not hurt to inspect..and see why you are down there.

Started on the blazer today found out the timming cover was a replacable once removed but the engine is under warrany and now have to wait..for a timming cover. The ruber u seal that goes on the oil pain area is still good should i leave it or would you replace it. I would like not too seeing how i would have to drop the oil pan a little and not to keen on starting new leak. Has any body ever added a bit of sealer in that area too sure it up a little. Just checking.. Thanks.. Gary

Started on the blazer today found out the timming cover was a replacable once removed but the engine is under warrany and now have to wait..for a timming cover. The ruber u seal that goes on the oil pain area is still good should i leave it or would you replace it. I would like not too seeing how i would have to drop the oil pan a little and not to keen on starting new leak. Has any body ever added a bit of sealer in that area too sure it up a little. Just checking.. Thanks.. Gary

Just have them worry about it under warranty.

Just remember, when changing the cover, the oilpan seal and the timing cover interloc... You need to make sure you use black rtv on the mating surface on the edges of the lower bosses at the interloc or you will end up leaking again.

Just remember, when changing the cover, the oilpan seal and the timing cover interloc... You need to make sure you use black rtv on the mating surface on the edges of the lower bosses at the interloc or you will end up leaking again.
Thanks I am waiting on the new cover now. The seal on the cover had a bad spot.I notice there was nothing on the black ruber seal at the oil pan. But i though it would not hurt putting a little sealer on it to make sure it wont leak after putting back together. Thanks.