Oil leaking from bell housing?

[KidKodiak]

I did an oil change on my 85 K20 burb and noticed oil leaking out a tiny hole on the bottom of the bell housing.

I can't imagine this should be normal at all. In fact I'm a little nervous.

The engine does leak oil pretty badly. What does this observation indicate?

Thanks for any and all advice.

[trbankii]

First guess would be rear main seal.

[KidKodiak]

Well that confirms my suspicions.

[trbankii]

Not too many options. Only fluid that is going to be leaking out of the bellhousing is either going to be oil past the main seal, gear oil/trans fluid from the transmission, or fluid from the torque converter (you didn't say manual or automatic).

Saying "oil" tells me the main seal is leaking. Any way about it, you're going to have to drop the transmission to take a look at things.

[Subzilla]

No need to drop the trans. Remove the TC cover and look for the leak. More than likely it is the rear main seal which can be replaced with the trans in place. Just a messy and tedious job dropping the pan to get to the seal.

[DmaxMaverick]

Correct. The rear main can be replaced w/o tranny removal. It's a 2-piece. Easier on a 4x4 than 2WD. Your biggest concern is going to be the seal type. It was original with a rope seal. They don't always come out nice. You'll be replacing it with rubber/steel.

Before you go digging into the bottom end, make sure the crankcase can breath out the top. If you have excessive blow-by, it can cause the rear main to leak. Installing a turbo will usually exaggerate this condition. Verify your CDR isn't obstructed or collapsed (which can allow excessive crankcase pressure, and a leaky main).

[KidKodiak]

Thanks for the info guys. I took the oil fill cap off, and there is a lot of blow by.

I started my 1984 M1009 CUCV, took the oil fill cap off - NONE. I'm happy about that, but not sure if it's a good point of reference for the Burban.

CUCV has 60k actual miles. Burban has 218k miles.

My uncle has owned a 1982 Diesel Burban that he bought directly from the GM proving grounds.

He told me he's run 20W-50 in it for years. His recommendation is that I use Wal-mart's Super-Tech 20W-50. I looked and it isn't designated specifically for diesel use. He says don't worry about it as he's got almost 400k miles on his without a hitch.

Do any of you experts have any feedback on this?

Lastly, My 85 Burban is 3/4 ton with a 700R4. Just did a mileage calculation after today's fill-up. 20.4 mpg. And that was towing 1,500 lbs in the city a few days last week.

Thanks again.

[KidKodiak]

For Subzilla, JohnC, Yukon and Robyn, I have been driving the 85 k20 suburban for a few months now.

I absolutely love it. But lucky for me I have a few issues with it.

Cold starts like a champ. When it the engine is warm, starts a little hard. I have to crank it twice before it fires, and hold the pedal a little bit. Otherwise it'll die.

This weekend I'll purge the fuel lines to make sure air isn't in the system, and replace the 8 short fuel return lines on the injectors.

If that doesn't solve the problem, then I'll just replace all 8 injectors and the IP.

I found a place near me that sells rebuilt injectors for $43 a piece and rebuilt IP for $390.

[JohnC]

His recommendation is that I use Wal-mart's Super-Tech 20W-50. I looked and it isn't designated specifically for diesel use. He says don't worry about it as he's got almost 400k miles on his without a hitch.

It's hard to argue with success, but I would never try it. I'm just not that lucky... The demands put on oil by a Diesel are much different from those of a gas engine. GM had many failures of roller cam followers in the early years and this lead to a reformulation of the oil.

[KidKodiak]

I agree, John. It may work for him, but I'll probably have problems. LOL. I think I'll just keep with the Rotella and add some Lucas to thicken it up. That'll probably be the best way to go.