[ptk013]

I'm at my wits end.

When I hard turn my 2015 Grand Cherokee SRT8 (85,000kms on clock) hard left or right, going forward or reverse at a slow speed (20km) in all modes I have a grinding noise.
It seams as though there is something that grabs and releases and feels like it is coming from the rear.

I have had the front CVs replaced.
Rear Bushes
Wheel Alignment

The below parts were fitted for testing but removed as have not remedied the issue.
Tailshaft replaced with a brand new genuine unit
Transfer Case motor replaced
Rear Differential Motor replaced with a brand new genuine unit
Drivetrain Control Module replaced with a brand new genuine unit
Harmonic Balancer replaced with a brand new genuine unit
New Tyres and Rims

 

[malamri424]

Sounds like the rear diff is locking up. Do you have a "service 4wd" message on?

 

[ptk013]

Sounds like the rear diff is locking up. Do you have a "service 4wd" message on?

No "service 4wd" message on.
Vehicle diagnostics was scanned.

I did have the rear diff changed (2nd hand unit) and brand new mopar oils.

 

[WUNFSTSRT]

Try drain and fill on the transmission fluid.

Sounds like a bad driveshaft to me! Is that what you replaced called Tailshaft ?

 

[White Elemant]

So no grinding when going straight, or cornering at higher speeds? And there are no visible wear marks anywhere?

Locating sounds may be vey difficult, so you may have to look at the front end after all... Check all suspension, gearbox/tranfercase and subframe bushings. Hard turns will put extra load on front geometry even at low speeds, and that may cause parts to chafe. It is also possible that if front driveline is being shifted due to steering loads, the driveshaft alignment will change causing it to grind in the rear end of it.

 

[Moparjim79]

This is a FWIW: I had a 2012 Overland that suffered this same problem, man was it embarrassing to drive anywhere slowly(picking kids up from school, etc), after a week i had the shits of it, I pulled all the wheels, disassembled the brakes, cleaned and relubed everything, and "adjusted" the splash shields slightly. Problem solved. Previously it was at the dealer for this same issue u der warranty. They replaced all the wheel bearings, the drive shaft, the axles, and front brake PADS, and it only lasted maybe 3 days and sound returned. If you have the experience, its a cheap thing to check out. I know the SRT Jeeps were plagued for awhile with groaning brakes, this was not my issue with the 2012, it straight up grinded.

 

[Wraith SRT]

I was going to say...rear brakes - they suck on these things.

 

[Rock-m-Sock-m]

Hello. We had a similar issue on our 2006 (WK) so you could try this; remove, clean and re-adjust the rear parking brake shoes. I'll bet there's a ton of rust in there and that can really cause some strange issues. Also, I would agree with MoparJim79 and make sure there's a clearance between everything and the splash shields.

 

[Stroked_SRT]

I'm at my wits end.

When I hard turn my 2015 Grand Cherokee SRT8 (85,000kms on clock) hard left or right, going forward or reverse at a slow speed (20km) in all modes I have a grinding noise.
It seams as though there is something that grabs and releases and feels like it is coming from the rear.

I have had the front CVs replaced.
Rear Bushes
Wheel Alignment

The below parts were fitted for testing but removed as have not remedied the issue.
Tailshaft replaced with a brand new genuine unit
Transfer Case motor replaced
Rear Differential Motor replaced with a brand new genuine unit
Drivetrain Control Module replaced with a brand new genuine unit
Harmonic Balancer replaced with a brand new genuine unit
New Tyres and Rims

I’m a huge fan of having the dealership mechanics diagnose and make the necessary repairs. They’re mostly trained on Chrysler, Jeep, Dodge products. It may take some time, but they’ll figure it out. As soon as you drive away and notice the same problem, call them and make arrangements to take it back. Having said that… at slow speeds, when turning in either direction, there are differences in speeds of outer wheels vs inner wheels. Those differences are absorb in the differentials, front & rear. The difference in speed between the front wheel and rear wheels are also absorb by the transfer. Can it be something else? Maybe, but that would be my starting points. Good luck!

 

[aweliky]

I'm at my wits end.

When I hard turn my 2015 Grand Cherokee SRT8 (85,000kms on clock) hard left or right, going forward or reverse at a slow speed (20km) in all modes I have a grinding noise.
It seams as though there is something that grabs and releases and feels like it is coming from the rear.

I have had the front CVs replaced.
Rear Bushes
Wheel Alignment

The below parts were fitted for testing but removed as have not remedied the issue.
Tailshaft replaced with a brand new genuine unit
Transfer Case motor replaced
Rear Differential Motor replaced with a brand new genuine unit
Drivetrain Control Module replaced with a brand new genuine unit
Harmonic Balancer replaced with a brand new genuine unit
New Tyres and Rims

Could it be your rear brake calipers? It sounds like the inside shoe could be stuck/grinding

 

[JpSchlienz]

This is happening in my 2014 srt. From a dead stop if I turn the wheel past 90° left or right it takes more throttle to accelerate and it feels like the rear end is shifting/clunking. Had the transfer case replaced 2 weeks ago, I just installed a new tccm, and my driveshaft is newer, maybe a year old. Service 4x4 light is on then it’ll go off but still acting the same way.

 

[ptk013]

Try drain and fill on the transmission fluid.

Sounds like a bad driveshaft to me! Is that what you replaced called Tailshaft ?

Yes the driveshaft (Tailshaft) was replaced with a new genuine unit. No change.
The transmission fluid was done roughly 5000ks previously.

 

[ptk013]

Could it be your rear brake calipers? It sounds like the inside shoe could be stuck/grinding

That is my next thing to try. I plan to change all the brake pads and new oil.
I'll let you know how I go.

 

[White Elemant]

Whatever it is, it will leave visble marks for sure.

What is the parkin brake arrangement in these? Is it similar to Wranglers where there are separate brake shoes inside the rotor hub?

 

[WUNFSTSRT]

Have you had the wheel bearings inspected?

Jeep Grand Cherokee bad wheel bearings symptoms, causes and diagnosis (wheelsjoint.com)

 

[ptk013]

Have you had the wheel bearings inspected?

Jeep Grand Cherokee bad wheel bearings symptoms, causes and diagnosis (wheelsjoint.com)

I'm pretty sure that the mechanics inspected the bearings.
In saying that it may be useful for me too replace them just in case.

 

[Moparjim79]

Please dont start throwing more parts at this. If its on someone else's dime, by all means, otherwise, you need to find yourself another dealer tech to approach this.....

 

[WUNFSTSRT]

Please dont start throwing more parts at this. If its on someone else's dime, by all means, otherwise, you need to find yourself another dealer tech to approach this.....

Yea never good to throw away money on parts if it's not proven to be the fix for the issue, it is however frustrating when you feel you have tried everything within your knowledge to remedy the issue.

But the reality is you will still end up spending money when asking a new shop to diagnose but at least you have a better chance than buying a part and finding out it did not fix the issue.

 

[dentonate]

I had this same issue on my ‘15 SRT and was told it was the rear differential. I had them replace the fluid and add the thickening (?) additive. Didn’t work at first but then all issues went away when the weather started cooling. No idea if correlated, just happy to not pay $5500 for a rear diff swap.

 

[Moparjim79]

The additive is Mopar limited slip lube, aka- whale spunk.