[twinturboz]

The pop noise could also be worn upper strut mounts, when you apply brake or acceleration it puts a load on the mounts and if they are worn it could make a pop sound.

 

[Enginerd]

Aren't the CV joints replaceable by your local driveshaft shop? (for MUCH less than $400/side)

That's a solution I didn't consider. If only the rolling elements are bad that might be an option. I wouldn't be surprised if the CV housings are proprietary, but maybe not. If it turns out the CV shafts are the issue, I will keep this idea in mind. Thanks

 

[Ironhydroxide]

I'd suggest checking the bolts on the CV's and make sure they're not loose. If they are, they could cause the clunk (at best) or tear out chunks of the transaxle while falling out
(at worst)

 

[element22rider]

Sorry to revive this thread yet again, but did anyone figure out what might be causing the drivetrain lash clunk noise?

 

[abenusa]

Hopefully it is not a precursor to what a couple of people have experienced... where the splines wear down on the electric motor shaft that mate with the gear in the reduction gearbox. Where that has happened, most people have no warning and all until a sudden shutter when shifting into drive or reverse.

 

[Enginerd]

@element22rider After all of my tests, my theory is at least on the Fiat I had, the majority of the backlash was inside the Drive unit. Perhaps in the differential due to thrust washer wear behind the side/pinion gears due to too many one wheel burnouts? Or maybe it was a design oversight or quality issue? I'm actually an EV Drivetrain engineer, but without a teardown for a root cause, it's impossible to say.

I sold my 500e after 16 months and approx. 5,000 miles and the noise never seemed to change. It always bothered me if I let it, but after a month or so it at least became expected. I sold it primarily due to significant battery degradation (25-40% depending on the measurement technique) but that's a topic for another thread. What I can say is the replacement Chevy Bolt has zero drivetrain clunks.

 

[element22rider]

Thanks for your reply - I see some new drive units are around $700 on eBay now so I’m tempted to swap mine and do a tear down

 

[Enginerd]

I considered doing the same myself but ultimately decided I couldn't justify such a purchase on a relatively inexpensive vehicle. But if you do, please let us know what you find! I don't know of any 500e drive unit teardown pictures/video out there yet so a lot of people would find that interesting/educational.

 

[Electric Tire Shredder]

@element22riderbattery degradation (25-40% depending on the measurement technique) but that's a topic for another thread.

It would be helpful if you'd create such a thread.

Just go to the forum home page (click here) & click in the field that says "Create a Quick Thread", right above the top thread ('15 500e Manuals & Brochure PDFs)

 

[FGC]

Hi there folks! I've got a 2014 500e I picked up a couple months ago. I've noticed that when I transition between accelerating/decelerating I get a clunk sound. Doesn't make any noise on bumps or anything, just when the transfer of torque changes direction on the motor.
This leads me to believe that it is one of the motor mounts in the car getting worn out. I've tried to take a peek underneath to see what I could find, but I wasn't able to determine which motor mount it is... Has anybody had this issue and might be able to point me in the right direction? The motor mounts for these are pretty expensive, so I don't want to end up buying the wrong one...
Thanks in advance!

View attachment 108622

Hi, did you ever diagnose the origin of the clunk?

 

[element22rider]

Mine might be a clunky drive axle but I haven't had time to jack up the car and look

 

[Electric Tire Shredder]

Isn't it relatively inexpensive to get new CV joints at a driveshaft shop?

 

[element22rider]

It might be cheaper but I think most of those places deal with the RWD and off-road crowd. Plus the downtime waiting for the rebuild

 

[Electric Tire Shredder]

What I really meant was a FWD half-shaft shop.

CV joint replacement is a very common repair, since SO many cars are FWD, & they seem to always eventually wear out, especially when the rubber finally cracks & nobody notices, so dirt & water get in & destroy the bearings.