ramyk

Just thought I'd post this as a cautionary tale to help you guys avoid unnecessary problems.

Took my car in to the dealer today because there's a whining noise coming from the diff at highway speeds under light load. The diff is now going to be replaced and the car only has 1200 miles on it. I'm very disappointed that something went wrong 3 weeks into ownership and this kind of makes me worry about what this car will be like further down the line.

Apparently this problem was avoidable if fluid levels were checked upon receiving the car (I'm clueless about these things but this is what I was told by another very helpful Z06 owner). The reason I'm posting this is to recommend that anyone who is taking delivery soon find a way to check their fluid levels to avoid this problem. I'm also feeling a little jaded since, as a person who does not know his way around an engine, I get the sense there's a whole load of other stuff I might be missing that'll manifest later on. I purchased a finished product and shouldn't have to have a service jack at home to find out what else is wrong with my $100,000 car.

jdmdohcpower

Yup,
Mine was low, checked it the day I got it. Took 3/4 qt.
Don't get me wrong I love this car and I have not had any issues with 8 track days on it so far (m7) but that's just embarrassing for GM. Just crap QC

ElCid79

There are actually instructions in the manual to check it. I will try to find a page reference later.

Sorry for your bad luck. Fortunately a differential isn't a big deal. I do find it odd that your fluid was missing. It very probably had a leak. So you may be better off anyways.

SBC_and_a_stick

It's not just the level that's the problem. The original fluid was chock full of debris. There seems to be a significant amount of break in particles with this eLSD. Flush it right away, and early the first few times.

jdmdohcpower

not that odd. Many have reported low diff fluid levels without leaks.

ElCid79

Thanks for pointing this out. I will check mine as soon as I get it back from the transmission shop.

ramyk

It's beyond me how they allow delivery with low diff fluid. If they're too busy at GM to check it themselves they should at least include it in the PDI.

Apparently it's common for fluid levels to be off in the Z06. Ridiculous.

Only thing I was aware I needed to do was the oil change at 500mi. Anyway at least whoever reads this will benefit in knowing they need to check diff fluid levels.

mdz06vetter

[QUOTE=ramyk;1590634038]It's beyond me how they allow delivery with low diff fluid. If they're too busy at GM to check it themselves they should at least include it in the PDI.

It is part of the PDI!!!! Very **** poor service at the delivering dealer

lgodom

I'm thinking Bowling Green gets the diffs from an outside supplier and doesn't check them during the assembly process as part of a quality check. They must be assuming the supplier is doing their job.

NSC5

With new vehicles I always check the diff level, give it a reasonable break-in for the first 150 miles (sustained high speed driving is definitely not good) and then I change the fluid between 500 and 700 miles. The fluid change has been a warranty requirement on the last few HD diesel pickups I have purchased and it is a very good idea to get the manufacturing and break-in debris out of any differential.

Most differentials may provide a long life without excessive noise even without this maintenance but if having a lot of metallic and friction materials in the lube was a good idea then it would be added as part of the lube production process

firstgear

That is what they are doing. They expect them to come in correct. That is the way modern manufacturing, particularly assembly operations run. You can bet that any warranty in the rear end also goes against the supplier.

It's a shame that suppliers negatively reflect on the OEM, but no manufacturer is perfect, not even Apple.

The manufacturer also counts on its dealers to do a check as well....obviously that never happened either.

Trawicked

You're absolutely right. Had mine replaced at the dealer this past Friday. There is also a software update to along with the replacement. Make sure they upload it.

harlold

I'd wonder what else in the PDI the dealer failed to do.

sammyv

I had read on this forum (months ago) about some 15's with low diff fluid. Op what year is your car?

ramyk

Wish I could, but I've never had to find out how to do this for any other car I've owned and shouldn't have to start now.

Not good enough. I hate to say this but, although I'm sure they have their own sets of failures too, if I would've bought a Porsche I doubt a problem would arise because of something as menial as fluid levels being off.

Thanks for the info, sorry you had this happen to you too. I'll be sure to point out the software update when they replace the diff.

Mine's a 16, delivered in the beginning of September.

anders1118

I have a 15 stingray and hear a whine from the diff when i'm at idle. Will be taking it in for an oil change next week and will have them check it out.

GETAGUN

Had my rearend replaced at 1500 miles.
Fluid full of metal and ****
Was originally told at 1100 miles it was normal and it needed to be broken in. Same dealer also never even drove the car to diagnose the problem.
Scan tool said its fine. Freaking parts changers.
Drove town the street to the GMC truck center and the diagnosed and had it replaced in three days.

ramyk

Good idea. Hope it's not the same issue.

Sucks man. Glad my dealer immediately recognized the problem and ordered the part. Is there a break in procedure for the differential that we're missing here or should the fluids just be checked and changed frequently? Don't want the same thing to happen again.

EdwardETraylorIII

My rear end was replaced in the first 200 miles due to the same issue.... The rear diff fluid checker guy at the factory may need a refresher course...

mdz06vetter

Delivering dealership needs better PDI process! That is one of the items that the tech checks as part of FLUIDS and obviously did NOT! GM pays the dealership for the PDI. I would really be talking with your dealership about EVERY service going forward.