Hello. I have a question I hope someone can answer. I have a '10 GT with about 130k miles on it. I think a lot of cars might do this but I am wondering if maybe something is worn or if there is an aftermarket part I can install in order to prevent this.

It rocks back and forth when accelerating. By that I mean it feels like the clutch is slipping, catching, slipping catching, and repeats a few times getting better and better until finally I have regular pull. I mean pull like the car is pulling and you are being pushed into the seat. This can be repeated by starting from a roll of 5-10mph for example, in first gear, letting off the gas, then suddenly depress the accelerator a good amount, if not all of the way down.

The tires are not spinning because I had someone watch. They just said the car looks like its rocking up and down as if the dampers were bad. Is that what this is? Is it just too much weight from the car being thrown back and causing something to slip (like a stock clutch versus a racing clutch). Or do I have something like a bad/worn thrust bearing? Does the suspension need tightened so that there is no sway back and forth from front to back?

I really don't know much about cars but that is all I can think to say. If you need me to record a video of it I will be happy to do so although I feel like this is a common enough thing that you guys will know what I am talking about.

Thanks.

Oh and one more thing. If I launch the car, this does not happen. The wheels will spin and then get grip and take off with no rocking. It only happens when the wheels do not spin out.
And I don't think this happens at high rpm.

 

Bump......

 

Don't rock your foot forwards and backwards abruptly while driving.

 

I'm not. For example, if I put my foot to the floor and keep it firmly there, it still does it.

 

Wouldn't be surprised if the clutch was giving out at 130k. That would show up at high load like that. Revs rising and falling while this is happening?

This many miles it could be as simple as needing a full tune up with new plugs, clean the MAF sensor, new air filter, etc.

 

rocking back and forth could easily be one side spinning until it catches traction again. Yeah, you said someone watched you. But that doesn't mean jack sh-it when it comes to a little slippage. If it were the clutch it shouldn't feel like a side to side motion. When the clutch starts to slip, less power is making it to both wheels, and the rpm's will rise and fall slowly depending on the clutches grip.

If it does it on different types of pavement, then you may need to look elsewhere for the problem.

*edit*
Is your traction control turned on or off? If it is on, then that would be your culprit.