Thunder22

2015 Z51 M7

I was in stop/go traffic last night and under load in 2nd gear I heard a whine from the rear end. It was intermittent, and I can't reproduce it at will, but it did happen about 10 times. It was 50* and 7p.m. on Long Island.

Last night was the first and only time I've heard it, but my question is:

Is this indicative of an impending bigger problem, or is this normal?

(I'm going to take it in to have it checked, but in the interim looking for other's thoughts)

THanks


(yes, I searched and I've read a lot of the threads, but it seems that most other people experiencing this are automatic Z06's)

Thunder22

Well, that answers my question, 137 views and no one else is having the issue. That's a good thing, hopefully it's nothing, or just my car.

Thunder22

Car is at dealer now and they have been able to reproduce the noise. It's definitely in the drive train somewhere and they are looking into it more closely now.

EDIT: The never looked at it.

eboggs_jkvl

Sorry, I've not experienced the issue. Post up the resolution for future reference.

Elmer

DickieDoo

Most likely the first thing they will do is change the diff fluid. How many miles and age on this beast ?

SpeedUp

Wasn't there an issue with some cars not having correct fluid levels in diff? Not sure if that was narrowed down to a certain batch or model - does anyone know ?

DickieDoo

i did have a very small leak in my 2016 Z51, noticed a few drops on the garage floor... hardly noticable but i am **** that way. So i took it in and they fixed it... was a pretty big job. might be that OP had a minore leak and enough fluid leaked out... from 2015

JerryU

My September 2013 built Z51 C7 received a notice to bring it in to check the level, which I did in October 2013. That was the first of 2 times I have had mine back for dealer service (the other was the recent seat belt recall.)

Watched as their newly trained C7 tech checked. He let me watch. It was 1/4 to 1/2 inch below the fill hole and was within spec. I have no noise from the rear or trans. Although the trans gears are large (particularly 1st and 2nd) and do make some noise but not excessive. The eLSD only has clutches on each side of a standard rear. If the noise is only in 2nd gear sounds like the trans.

themonk

The only whine I hear is from the OP.

I've never heard a whine on mine (54k kms) but yesterday I had the "service rear axle" warning come on, I just chalk it to it being -26 C outside. You did the right thing, have a tech look at it that way, at the very least, if something does happen you can say you got the all clear from the dealership....not that they would refuse your 60k mile warranty claim anyway.

GLWR (good luck with repair).

Thunder22

~ 6000 2015 z51

Thunder22

shaddup


and thanks.

i figured it's better to have it in the shop in December than spring, so I'm not rushing them either.

Thunder22

That's just it, it sounds like either the elsd clutches are either having trouble engaging or disengaging, but I'm just guessing, it's with the experts now and they can reproduce it from 1st to 3rd, so I'll leave it with them to diagnose.

JerryU

Hmm, and I'm complaining about the +26 F it will be tonight (a record low for us this early in December!) That is -3C.

At -26 C (-15 F) believe I would crack, not just my tires!

JerryU

Will be interested in what they find, assume both sets of clutches are fully engaged in bumper to bumper traffic, or at least should be!

Bmwmike

Just wondering what dealer you used. Im also on Long Island and im always interested in feedback from dealers in the area.

brooklync5

Just make sure to stay far away from Paul Conte Chevy they are the most unprofessional disgusting group of people I've ever met. I've been using sunrise Chevy in forest hills queens.

jaden61

Mine had a whine when new. I put service advisor on notice. I now have 22k miles and don't hear it any more.
Also just recently had "service rear axle" pop up on DIC. Happen when 2 times while paddle downshifting an A8. Service looked and seen nothing but did update rear axle with new software.

Thunder22

Quick update: The cold weather has seriously hampered the ability to drive the car and diagnose the problem (low 40's to low 30's). Considering that the weather won't be getting any warmer, we agreed that I would take the car back and we would re-evaluate come early spring.

edit: dealer never resolved issue

pharaoh4269

Want to throw my hat in the ring on this one Ty for starting the threads and the research thus far Thunder22.

2016 Z51 M7 Stingray, 5800 miles.

I as well have begun experiencing the "groan" from the drivers side rear end of the car. Seems to last about 1 to 2 seconds during each groan.

Significantly more frequent under two conditions:
- Cold of two varieties outside temp (30 to 40 F) and when the drive train is cool as well.
- Low speeds, 0 - 50 ish?

Only happens (for me) with the drive train engaged (gears 1-3) and under light load, usually foot off the gas (still moving 5-25 mph) in traffic waiting for people to find the accelerator. I have experienced no link to shift timing. My thought is the eLSD, no vibration in my clutch.

Seems as though the sound is becoming more frequent, however it is intermittent enough at this point that I am not confident in my dealers ability to reproduce.

Any update on your end Thunder, anyone else experiencing?

TY all

Thunder22

I'm sorry I don't have any further info as I took the car back from the dealer because the weather here in NJ prohibited any further testing. They did open a warranty claim with GM to document the problem, and I'm going to bring the car back once the temps get above 40 consistently.

That being said, your problem sounds exactly like mine.

The service manager where I took my car suggested that I document when it occurs and any details about temps, traffic conditions, gear, etc. etc.