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Hey guys I don’t really drive my G that much it only has 60k miles. Today I took my G on a trip from NYC to Boston on the way there I ran over a tire tread I wanted to make sure everything is good so at the rest area I got under the truck and saw this has been leaking for a long time as the oil was all caked up and melted on.
what is this thing called and is this common to leak?
i had to take my truck to the dealer anyway for the valve cover leak but it’s good I saw this too
anyone please can help me out thx
SO AFTER GETTING IT FIXED 1500 MILES AGO IT LOOKS LIKE THIS? IS IT JUST ME OR DOES IT LOOK LIKE ITS STILL LEAKING?
That looks indeed like a blown pinion seal. You should check (or have checked) the axle vent / vent tube to make sure it's it's not blocked so that the pressure built up in the axle when it gets hot is not forcing the differential oil out the seal. If the seal is bad, have the pinion bearings checked for excessive play because the seals don't usually fail at your mileage.
Truck will be going in for service when they have a slot open, will also have them do my valve cover which started to leak and check out a random CEL I get and loss of power only in C mode going uphill 1/20 times. Its weird I never noticed any oil marks in my garage and even today no oil marks it seems to just clump up there. apparently the leak from the pinion seal travels down to the diff they said its very common around 60k-80k they said its also because how bad the NE winters get? Not sure about that.
Where would I check to see if the vent is blocked?
Some what common, mine had to replaced and so far so good.
There were other areas with oil seepage as well.
Good idea to do a visual check now and then.
There is plastic tubing the goes from a fitting on the axle up into the engine compartment to vent the axles. MB does this so they do no fill with water when the axle is submerged fording deep water. Make sure tube is not bent or kinked and check to make sure the fitting is not clogged.
Replacing the pinion seal can be touchy business as the pinion bearing pre-load is set via a crush sleeve. Hopefully the mechanic who does it has some experience with it.
Last edited by Floobydust; 04-17-2020 at 12:35 PM.
Reason: one more thought
had it fixed 1500 miles ago at the dealership, i looked under yesterday doing an oil change and still noticed it looking like it leaking....or would u say its old residue
Hmmm. Hard to say, but it looks like it's wet in the picture. I would have hoped that the mechanic would have put a few minutes of effort into cleaning up the mess after he did the repair. I'd ask the dealer to take a look just to make sure it's not still leaking. Then, I'd ask them to clean up the mess (if it was left over from the initial repair) so it will be easier for you to see any future leaks.
Yea it looks like the oil that was from the original build up is just baked onto the housing. It's like having a cast iron pan that's been "seasoned" so it always looks like there's oil in/on it even though there isn't.
Like stated above, if you're not down to clean it, have it cleaned and document what it looks like after cleaning. Take it out for a couple days of driving then hop back down there and compare a cleaned photo to the current state.
04-16-2020, 02:14 PM
