I have noticed my MCS has stated pulling to the left slightly when accelerating hard and shifting. When down shifting, it pulls the right. Has anyone else had this problem? If so what is causing it.

 

i'd start w/ the cheap things.

check your tire pressure, then tire condition, then alignment.

 

My 04 MCS does this every once in a while - I attribute it to the FWD ( torque steer ). I also have the run flat tires that grab the ruts in the road -- so it could be either one:impatient

 

I noticed it after hitting some road debris. I have since replaced the front left wheel and tire, repaired the left rear rim, rotated and balanced all 4 wheels, and had a 4 wheel alignment. My dealer did a visual inspection of the suspension and did not notice any damage. I guess my concern is whether the differential could have been damaged or not.

 

what size wheels and tires are you running??

did you check the tire wear and pressure yet??
my local garage is notorious for pumping up the tires to
the limit marked on the sidewall.

 

Have the front suspension bushings as well as the upper strut mount checked. Both of these areas have rubber that can crack and become 'sloppy' under stress (acceleration and braking). Also check for play or looseness in the steering rack and it's mountings.

A pull under accel and braking after having damage is often caused by a still bent part remaining in use but having the alignment brought back by an adjustment. If a lot of adjustment was needed to bring things back in spec compared with the opposite side, the geometry of the suspension/steering becomes asymmetrical and will suffer as a result.

 

Thanks, I will do that.

 

I had the same problem and was told it was normal, but I insisted that it was not the way it drove when i bought the car. I was lucky that a factory rep was at the dealership that day and he found a loose balljoint. The problem went away immediatly. I would have your dealership check that as well.

 

well, if it was your differential, it would make a good excuse to get a quaife...