2000 GTP Bizarre Shudder?

[bangbg]

I have an unusual symptom that is occurring in my 2000 GTP 2-door coupe and would like input if anyone can make sense of the problem.

The car has 135,000 miles on it and runs smooth at idle, accelerates without hesitation and gets an average of 23 MPG day in and day out. I put about 400-500 miles per week on the car as a daily driver. The struts were all been replaced with KYB lifetime units about 10,000 miles ago. The tires are BFG Traction T/A and have about 10,000 miles on them, are balanced and in good condition and are inflated to the correct pressures and checked weekly.

I recently noticed that when accelerating while making right hand turns, on freeway onramps for instance, the car shudders as it is accelerating. If I do not apply the throttle but make the same corners without applying the throttle the car is fine and smooth. It does not do this on left turns or curves if you will, nor does it exhibit the shudder when applying even full throttle when going straight. Another aspect of this seems to be that the shudder can be induced in straight line acceleration when the suspension is compressed, like when the weight of the car is pushing down going over a road that is smooth but has high/low spots in the pavement.

I typically travel alone in the vehicle when it exhibits this symptom. I recently realized that there is a second part to this problem. When the load in the car is increased, ie. 2 or more occupants, it exhibits the shudder when accelerating even in a straight line, but is smooth at constant speeds after reaching cruising speed.

I have racked my brain trying to evaluate what could be causing this. The upper dog-leg motor mounts are new and one lower motor mount has recently been replaced, I think there are still 2 more lower mounts that are original. I was thinking they could be the problem.

Any constructive thoughts on this would be appreciated. I have been amazed in the past at the evaluations of some of you forum members and hope you can help me.

-Dan

[Niq]

When I say this, I’m asking the experts here in the forum…. Is it the wheel bearings? I hear alot about the wheel bearings being a weak spot....

[richtazz]

I would suspect the drivers side hub bearing or axle shaft. Both would cause a shudder under acceleration and/or lateral forces. If the ABS/Trac off lights are on, it's definitely the hub bearing.