Cars&Airplanes

I have confirmed I have oil dripping from inside the bell housing. My question is it possible my oil leak is coming from somewhere other than the rear main seal?.... Can something else be the culprit and migrate down through the bell housing?... Thank you in advance for your experience and advice.

PSDCampervan

I'd suspect a component in engine valley where oil cooler lives (which is notorious for leaky seals from what I've read). Oil pools in valley, then cascades to rear of engine & drains down path of least resistance outside of bellhousing on driver's side (USA vehicle).

dieseldoc

+1, had this with my GL320cdi. Very common problem.

DennisG01

Can a drip from INSIDE the bell housing still be something else, other than the rear main seal? I have the same drip as you, Cars. It's never enough to drip onto the driveway, but it is always present on the lower lip of the bell housing and it does NOT drip down the outside of the housing.

Fourdiesel

It is my understanding that the joint between the engine and the bell housing is NOT gasketed. Therefore, oil from the V6 'valley' can, and does, get into that space. It runs (drips) out the lowest point.

DennisG01

Thanks - I figure it wasn't gasketed - just wasn't sure how tight of a fit it actually is and whether oil would follow a "path of least resistance" down the side, instead. I had cleaned the turbo intake area, where the intake box attaches, a little while ago. I'll have to go back and look for leaks. The seal "seemed" OK, but who knows.

alx

your oil cooler seals are leaking.

DennisG01

In my case, at least, that would mean the shop that just replaced them either didn't do it, or did a poor job. When I bought the vehicle, they said they had done the seals because they were leaking. The oil leak has been there since day one of my ownership.

I would imagine there's lot's of info out there on this, but are they relatively easy to check? I'm imagining their kinda buried?

Petronio

Hi.
I changed the rear crankshaft seal of my 2007 GL 320 CDI, but the leak continues. Mechanic says there is wear on the shaft. He says there is kit that brings a circular shim and a tool kit to install it. Do you know where can I buy such a kit.

Best regards.

Rattlebox

Engine oil cooler seals leaking not the rear main seal

Petronio

Rattlebox

Also how many miles are on your vehicle?

Petronio

Rattlebox

miles? or Kilometers? and have you done any other major repairs?

Petronio

Rattlebox

wow thats pretty amazing...... I have just purchased this 2009 GL 320 CDI with 133K miles on it and so far im very dissapointed, Im having to replace timing chain and tensioner already.........

Petronio

Rattlebox

Well damn with 249k thats pretty good for a transmission

sak335

If you think that's disappointing, I had to replace my timing chain at 55,000 miles! That's disappointing! If you need a guide for a job, I did a write-up and posted it to the diesel forum.

For the OP, I agree this sounds like oil cooler seals. Before you go that route though, check the turbo air inlet seal (the red, round one.) Mine was leaking and causing a similar oil drip.

IronPTA

I thought the same thing when my turbo inlet seal was busted and leaking down around the bell housing and even inside the bell housing. The trick is to pull the rubber plug on the lower side of the bell housing and see if it is running down the flywheel or back of the block. Then check the turbo inlet seal which is commonly busted. The PCV valve will allow oil particles into the turbo and they run out and down to the "valley" above the oil cooler, run down the back of the block, through the bell housing and down the driver's side of the transmission and onto the pavement/concrete. You may invest in a boroscope from eBay. They are only ~$20 and you can see the oil cooler to see if it is indeed leaking and run it up from the bottom to see if the oil is originating above the bell housing.
I just purchased a Gl320 with 160k miles and was happy to see that you have 250k miles on yours.

Good luck and let us know what you find.