[Mr. Wyndham]

Originally Posted by JANNETTYRACING

NO change what so ever.

They called today they want my car at the dealer so GM Tech support can link in to my car and look things over.

Personally I don't think it is computer/electrical related, I think it is mechanical and I need a new diff.

I don't think the diff is responding to commands.

And if I read right, the diff returned a clutch error code and they've got a new one on order for you?

[TMS]

I too have been curious about how the eLSD actually works and how it compares to true torque vectoring differentials. I ran across what appears to be the patent application on the GM eLSD. Interesting read for inquiring minds.

https://drive.google.com/file/d/1pVh...w?usp=drivesdk

I am following this thread closely to pick up new knowledge directly on this steer problem and indirectly on the eLSD.

Good luck Ted. At least GM and dealer seems to be actively engaged to remedy.

[JANNETTYRACING]

Originally Posted by Mr. Wyndham

And if I read right, the diff returned a clutch error code and they've got a new one on order for you?

I called again they said they are not allowed to order a complete diff unless GM tech authorizes it after they run this test.

Ted.

[Mr. Wyndham]

Originally Posted by JANNETTYRACING

I called again they said they are not allowed to order a complete diff unless GM tech authorizes it after they run this test.

Ted.

Ahh, Gotcha. Well - sounds worth the investigation. Thanks for keeping us updated!

Once it warms up around here, I'm going to have to try and test this out on my car...haven't noticed it before...so I don't know if it's there.

[bobby35ny]

Car was less than 24hrs old when the problem appeared.
High end car, I'm surprised that GM wont take the car back and give you another one.
I'm sure they would love to do forensics on the car.

[JANNETTYRACING]

Originally Posted by bobby35ny

Car was less than 24hrs old when the problem appeared.
High end car, I'm surprised that GM wont take the car back and give you another one.
I'm sure they would love to do forensics on the car.

Just dropped it off the Lead World class Tech is working on it.

Ted.

[Mr. Wyndham]

Originally Posted by bobby35ny

Car was less than 24hrs old when the problem appeared.
High end car, I'm surprised that GM wont take the car back and give you another one.
I'm sure they would love to do forensics on the car.

Not a high volume car, and it doesn't sound like the car as a whole has a problem, just the diff. If this is anything like some of my past experiences, there will be a field engineer involved, shortly....

[bobby35ny]

Originally Posted by Mr. Wyndham

Not a high volume car, and it doesn't sound like the car as a whole has a problem, just the diff. If this is anything like some of my past experiences, there will be a field engineer involved, shortly....

Exactly! Not a high volume car. all the more reason to park it and tear it apart to find out what's going on. Hey I know that wont happen, just surprised that's all.

[waterman]

Originally Posted by JANNETTYRACING

Just dropped it off the Lead World class Tech is working on it.

Ted.

Continuing to follow with great interest.

Thanks for keeping us updated Ted.

[Ecchi667]

Tramlining (Tram-Lining - taken from Wikipedia because I got lazy): "Tramlining is the tendency of a vehicle's wheels to follow the contours in the surface upon which it runs. The term comes from the tendency of a car's wheels to follow the normally recessed rails of street trams, without driver input in the same way that the train does. The same effect is sometimes called Nibbling."

I get some tramlining in the Camaro. I believe it's due to having noticeably wider rear tyres. The 30mm difference between front and rear is a little over an inch, so noticeable.

Mentioning torque steer - that's more an issue for FWD cars. My Clio 172 Cup had it a little bit. It could technically happen in AWD and RWD cars, but not to the same extent. Best way I can describe that feeling is when you are accelerating a rear wheel drive car and you let go of the steering wheel, it pulls to the angle of the front wheels as they sit and drives straight from there. If you let go of the wheel in a front wheel drive car under those same conditions, it'll yank the front wheels to the angle of the rear wheels - straight ahead. Similar to coming into a corner too hard and locking the brakes up.

Question - when this lane switching happens, does the car actually accelerate, maintain a steady pace, or slow down? Rather than a slip, it sounds more like a lock to me - and I'd expect to see a sudden but slight drop in speed. The left of the car is locking up and that drag on the tyres is tugging the car to the left. The right is still moving freely, as it has no such resistance.

I'm assuming you've tried comp mode and completely disabled traction control to see if you have the same issue there? If the rear left brake was locking (or front left brake I guess) then it'd pull like that.

Just some thoughts. Good luck!

[JANNETTYRACING]

Originally Posted by Ecchi667

Tramlining (Tram-Lining - taken from Wikipedia because I got lazy): "Tramlining is the tendency of a vehicle's wheels to follow the contours in the surface upon which it runs. The term comes from the tendency of a car's wheels to follow the normally recessed rails of street trams, without driver input in the same way that the train does. The same effect is sometimes called Nibbling."

I get some tramlining in the Camaro. I believe it's due to having noticeably wider rear tyres. The 30mm difference between front and rear is a little over an inch, so noticeable.

Mentioning torque steer - that's more an issue for FWD cars. My Clio 172 Cup had it a little bit. It could technically happen in AWD and RWD cars, but not to the same extent. Best way I can describe that feeling is when you are accelerating a rear wheel drive car and you let go of the steering wheel, it pulls to the angle of the front wheels as they sit and drives straight from there. If you let go of the wheel in a front wheel drive car under those same conditions, it'll yank the front wheels to the angle of the rear wheels - straight ahead. Similar to coming into a corner too hard and locking the brakes up.

Question - when this lane switching happens, does the car actually accelerate, maintain a steady pace, or slow down? Rather than a slip, it sounds more like a lock to me - and I'd expect to see a sudden but slight drop in speed. The left of the car is locking up and that drag on the tyres is tugging the car to the left. The right is still moving freely, as it has no such resistance.

I'm assuming you've tried comp mode and completely disabled traction control to see if you have the same issue there? If the rear left brake was locking (or front left brake I guess) then it'd pull like that.

Just some thoughts. Good luck!

It is simply all the power is being applied to the right rear wheel under moderate acceleration pushing the car in the left lane.

Very light throttle cruise you can let go of the wheel.

Hard acceleration it spins the tires and goes straight.

Nothing is dragging or locking up car accelerates normally in all conditions.

Ted.

[Nick S]

Originally Posted by JANNETTYRACING

It is simply all the power is being applied to the right rear wheel under moderate acceleration pushing the car in the left lane.

Very light throttle cruise you can let go of the wheel.

Hard acceleration it spins the tires and goes straight.

Nothing is dragging or locking up car accelerates normally in all conditions.

Ted.

Hey Ted,
I was thinking about this the other night and was thinking about what you are guessing the problem is (only one wheel getting power). Wouldn’t rear wheel drive vehicles with an open diff (i.e. no form of locking differential) experience this problem all the time since they are always only getting power to one wheel? It just seems to me that if the root cause is all power going to only one wheel then open diff cars/trucks would have the same issue all the time. Am I not fully understanding an open diff?

Good luck getting your car issues resolved ASAP. Really sucks to get a new car and have issues like this already.

[*007]

Originally Posted by Can'tHave2MuchHP

Ted's issue is separate from the "Floating" feeling that some/all? ZL1 owners experience. Thankfully GM has gotten the issue, but hopefully it gets resolved in some sort of a timely manner. I'd be pushing for a buy-back myself.

I haven't driven my ZL1 yet but I'm guessing it's guaranteed that I'll feel the rear end float.

Possible that both Ted's problem and the "floating" feeling are both related to a new fangled ELSD that maybe wasn't quite ready for production?

Actually, this “floating” is likely designed in to allow the ZLE drive experience to parallel that found in the W Body HC and attract those possible purchasers.

[JANNETTYRACING]

Originally Posted by Nick S

Hey Ted,
I was thinking about this the other night and was thinking about what you are guessing the problem is (only one wheel getting power). Wouldn’t rear wheel drive vehicles with an open diff (i.e. no form of locking differential) experience this problem all the time since they are always only getting power to one wheel? It just seems to me that if the root cause is all power going to only one wheel then open diff cars/trucks would have the same issue all the time. Am I not fully understanding an open diff?

Good luck getting your car issues resolved ASAP. Really sucks to get a new car and have issues like this already.

Even though an open diff will spin 1 tire it does not have the ability to apply power to 1 wheel.

This diff has the ability to apply power to one or the other axle through the ELSD.

Ted.