Rear Main? Pics

SComp23 · 05-16-2006, 01:35 AM

I have a 1998 Blazer 4.3 2wd 4L60E tranny. Anyhow, I thought my rear main was leaking, so I had it replaced. Never leaked too much, just a little bit of oil that would come out of the weephole every once in a while, just enough to be annoying you know? So today I cleaned the bottom of my engine with some degreaser, and there is STILL a bit of oil that comes out of the weephole on the tranny bellhousing. What gives? I took off the inspection plate (the small silver circle in the pic used to access the flywheel to turn it), and there looks like there is a very small bit of oil on the back of the engine block. What is going on?

BlazinMlew · 05-16-2006, 08:20 AM

I have the exact same problem. I have no clue what the deal is, so I am just as interested in any answers as you.

joeuser742 · 05-16-2006, 01:04 PM

Hmm, could it be coming from the oil relocation lines? When I replaced my rear seal, I was really careful not to stretch the new seal. It could be coming from the oilpan. I'm sure you did, but gonna ask anyway...did you drop the oilpan before you put the rear seal on? I put some of that gasket maker stuff all around the seal housing (not the seal itself) and oilpan before I put it back together.

SComp23 · 05-16-2006, 01:12 PM

I did not do the seal myself unfortunately so I am not quite sure. The oil is definitely coming out of the weephole though because I cleaned the engine to determine where the leak was coming from, the rest of the bellhousing and engine are clean.

joeuser742 · 05-16-2006, 03:19 PM

I would say then that whom ever did the job might not have done it right or possibly even mixed the parts up and put the old one back in. When I took mine out, I couldn't tell if I mixed them up. The old one looked good, but wasn't.
Do you use synthetic oil? I noticed that mine was leaking after I started using it.
Well, not sure if you want to get your hands dirty, but you can drop the oilpan fairly easily and check the oilpan gasket, or change it.

SComp23 · 05-16-2006, 03:28 PM

You can not drop the oil pan on a 2wd without removing the engine. Also, I would have to imagine that the old seal would be covered in oil, while the new one would not be, so accidently putting the old part back in shouldn't even really be an issue. Also yes, I do run full synthetic.

OverBoardProject · 05-16-2006, 07:51 PM

I believe that there's a vent somewhere, and if this were plugged it would cause that problem.

Just something to look into.

SComp23 · 05-16-2006, 11:27 PM

Any idea where the vent it on these trucks?

OverBoardProject · 05-16-2006, 11:47 PM

Somewhere neer the top. I can't promise that it exists, since in theory the fill tube also acts like a vent. Someone else has always done my auto transmission work

SComp23 · 05-16-2006, 11:49 PM

I am talking about the rear main seal on the engine, not on the tranny

OverBoardProject · 05-16-2006, 11:53 PM

Oh, Sorry.

Make sure that the PVC valve is clear, and that the vent tube on the other valve cover is also venting. They can easily get plugged or even kinked.

BlazerLT · 05-17-2006, 01:15 AM

Check your PCV valve in the driver's side valve cover and the fresh air intake from the passenger and make sure they are clear. You might have elevated crankcase pressure from a non functioning or plugged PCV system.

Other than that, take it back to the shop and demand a refund or have them fix it.

They might have pulled a fast one on you.

BTW, that fluid looks aweful red, do you think it might be tranny fluid?

SComp23 · 05-17-2006, 01:20 AM

Hey LT,
It must be the picture, it is certainly oil because when I put a piece of paper towel up in the weephole the fluid is a very light tan (new oil) color. I pulled out the bellhousing rubber plugs and looked up in the bellhousing, and it looks like a very tiny amount of oil on the back of the engine. I also was thinking about them possibly not doing the work, but I know the transmission had never been removed previously, and I can tell the crossmember, tranny, and exhaust has been dropped.

BlazerLT · 05-17-2006, 01:25 AM

Hmmm....

I would take it back then, you paid for a job you didn't receive.

Hunter1 · 05-17-2006, 11:25 AM

I just did a rear main a couple of weeks ago. The oil pan can be considered as part of the bell housing. there is a sort of half moon shaped gasket that goes behind the main seal gasket that could be a source, also the oil pan gasket as it goes around the crankshaft housing is the other source. For a pic of the rear gasket set goto http://www.partsamerica.com/ProductD...pe=105&ptset=A

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