New member - oil leak question.

[Modest_Man]

Hey guys. I joined a while a go and have been browsing the forums. Lots of good info on here.

Here's my story. I received a 1971 C10 as a gift from my folks when I turned 15, 13 years ago. Drove it through high school and then it sat through college, getting married, and buying a house for close to 10 years. Finally took it from my folks and am going to get it back into driving shape.

In high school I managed to throw the timing chain so we swapped motors with a new GM crate 350. It has leaked oil since day 1 (trying to get the dealer to cover the leak under warranty was a terrible experience), and I'm finally getting around to trying to fix it. We always figured it was the rear main seal, so I dropped out the transmission (3 speed manual is my favorite transmission of all time) and snapped some photos to get some other opinions before I tear into it more.

I've got oil all over the outside and inside of the bell housing, as well as the transmission (engine oil, not transmission oil), frame, and motor mounts. It leaks a lot of oil when running, a 4-5 puddle each time, with drips up and down the driveway. The valve cover oil leak is very obvious, but I believe that to be from me driving it recently after the truck sat for several years. Though, is it possible that the oil leaked from the valve cover, down to the clutch fork, and into the bell housing that way or seeped down between the bell housing and engine mounting surfaces? It's not leaking from the manifold, the oil filter, oil pressure sending unit, or the oil pan gasket. So it's a toss up for me currently if I do the valve cover gaskets, or the rear main and the valve gaskets too. Or it could be something else entirely, who knows!

Something to keep in mind is that this is a newer engine so it has a one piece rear main instead of the two piece that these trucks usually have.

Thanks a bunch,

Jamie

Bell housing


Oil Pan


Oil and sludge built up inside bell housing


Oil on clutch fork


Top back of engine

[463]

From past experience I had to replace a leaking one piece rear main seal mind you it had a auto trans bolted on to it.
The photos look much the same as what I saw when my replacement was taking place.
The photos sure help to understand what is going on.

[463]

to the form

[Modest_Man]

Originally Posted by 463

From past experience I had to replace a leaking one piece rear main seal mind you it had a auto trans bolted on to it.
The photos look much the same as what I saw when my replacement was taking place.
The photos sure help to understand what is going on.

Great, good to hear that my hunch and your experience are similar. Looks like I get to go pull off the bell housing and take out the clutch!