[NOLAGUY]

Do the 2017s have any known rear differential issues? I have a 17 and over the weekend I was going slowly up a steep driveway and I heard something that sounded like I scraped the ground. It happened 3 times in total.

[gmzanatta]

Some of the earlier run cars did.

Depends on when your car was produced.

[NOLAGUY]

Mine was delivered in October. Is that early?

[slashrawr]

Could it be the "soda can crunch noise"?

[gmzanatta]

Originally Posted by NOLAGUY

Mine was delivered in October. Is that early?

What was your production week?

[Glounk]

I thought it was the rear diffuser !!!!!

[gmzanatta]

Originally Posted by Glounk

I thought it was the rear diffuser !!!!!

If your rear diffuser is making the noise, you're not doing it right

[NOLAGUY]

Originally Posted by gmzanatta

What was your production week?

Week 37

[gmzanatta]

Originally Posted by NOLAGUY

Week 37

Hmm you're at the tail end of it, but could have still been affected, but I think you're in the clear. Get your dealer to look into it.

[DETRoadster]

I'm still far from convinced that there arent any yet to be diagnosed (or admitted to) diff issues in the 2017. I'm hearing noises back there that I really struggle to shrug off as rocks in the dust shield. The most recent crunch was accompanied by a screech like a tire or a clutch pack locking up and the right rear of the car actually lifted up.

[NOLAGUY]

I'm going to try and repeat/record it during lunch today. If I can I'll upload it.

[gmzanatta]

Originally Posted by DETRoadster

I'm still far from convinced that there arent any yet to be diagnosed (or admitted to) diff issues in the 2017. I'm hearing noises back there that I really struggle to shrug off as rocks in the dust shield. The most recent crunch was accompanied by a screech like a tire or a clutch pack locking up and the right rear of the car actually lifted up.

I can (unofficially) guarantee you that there are

[Nicname]

Originally Posted by DETRoadster

I'm still far from convinced that there arent any yet to be diagnosed (or admitted to) diff issues in the 2017. I'm hearing noises back there that I really struggle to shrug off as rocks in the dust shield. The most recent crunch was accompanied by a screech like a tire or a clutch pack locking up and the right rear of the car actually lifted up.

Same for me. There's times I'm driving through the city in stop and go traffic and hear something and look back to make sure I wasn't clipped by a bicycle or nudged by another car. This car makes some weird noises in the back...

[King_Slayer]

Originally Posted by DETRoadster

I'm still far from convinced that there arent any yet to be diagnosed (or admitted to) diff issues in the 2017. I'm hearing noises back there that I really struggle to shrug off as rocks in the dust shield. The most recent crunch was accompanied by a screech like a tire or a clutch pack locking up and the right rear of the car actually lifted up.

Man this is certainly something I don't wanna hear before picking up my car. Felt like the car lifted up?!

[gmzanatta]

Originally Posted by King_Slayer

Man this is certainly something I don't wanna hear before picking up my car. Felt like the car lifted up?!

Makes sense. The issue with the diffs was poor quality/fitment of gears that could lead to fast wear or total failure.

If the car got 'lifted up', it could've been gears coming out of mesh.

[King_Slayer]

Originally Posted by gmzanatta

Makes sense. The issue with the diffs was poor quality/fitment of gears that could lead to fast wear or total failure.

If the car got 'lifted up', it could've been gears coming out of mesh.

Have you experienced this?

[gmzanatta]

Originally Posted by King_Slayer

Have you experienced this?

Hahaha loooong story, but no. My diff was replaced after car was delivered, paid for it to sit there for 2 months. You can read all about at in the main "Canadian Deliveries" thread.

And add your info too

[mofomat]

Originally Posted by King_Slayer

Have you experienced this?

I have, last week.

[King_Slayer]

great....

[DETRoadster]

Mofomat, I'm interested in understanding whether you feel like there's considerable drivetrain slop in your car as well, seeing as how we have both experienced the "hop". I've noticed when I am at light cruise or light acceleration, then lift the gas pedal, I get a little "knock" from the back end. Thought it was slop in the driveshaft u-joints, but perhaps it's differential gears with too much clearance loading and unloading.

[reppucci]

Originally Posted by DETRoadster

Mofomat, I'm interested in understanding whether you feel like there's considerable drivetrain slop in your car as well, seeing as how we have both experienced the "hop". I've noticed when I am at light cruise or light acceleration, then lift the gas pedal, I get a little "knock" from the back end. Thought it was slop in the driveshaft u-joints, but perhaps it's differential gears with too much clearance loading and unloading.

I had/"have" this! Like you couldn't tell if u-joint diff, load/unload or perhaps diff housing bushings. Only happens under light load and when changing gears slowly so the rpm match kicks off. I have a 6MT. A knock from the rear of the car.

My diff was replaced under the recall last month (early December). I was going to check if I still had the "slop" after the diff was changed. I only drove her 2-3 times after diff replacement before I put away for the winter. I can't swear to it but I have a vague recollection the slop was still present suggesting u-bolt and not diff related.

When I take her out again after the winter, or if a long warm spell, I will update you.

[chris719]

In my Z4M the rear diff would clunk if you unloaded it a certain way at low speeds. Might not be that abnormal.

OP's issue sounds like the rocks in the brake shield.