I'm gonna try to make this as understandable as possible.

I had Tein S-Tech springs on my 04 coupe and after some time, I noticed that while accelerating anywhere between mid throttle to WOT, the car would pull to the left.

But while in cruise control, coasting or braking, the car is straight as an arrow. Also I had noticed that if I rolled over dips at highway speeds, it felt like the car would feel as if the rear end would try to roll out to the right...Almost like I turned the wheel slightly to the left when I hit the dip.

Also at highway speeds, turning on long right turns, I feel a vibration in the car and it seems harder to turn right than left. Turning left at highway speeds feels normal or even a little loose.

I changed out the suspension and installed SPC rear camber kit. I was able to get everything in spec except for the front camber being -2.25 on both sides. I assumed that would fix the problem...

NOPE! Still not tracking straight, and the car also feels really squirrley if I'm turning left from a stop light. It always tries to break loose, even at 1/3-1/2 throttle.

I'm baffled at this point and so is everyone I've talked to. Two dealers and numerous mechanics.

I did notice that my rear brake pads on the left side wore down to nothing in roughly 15k miles while the right side still had plenty of meat.

Sorry for the long post guys but I needed to get as much info out as possible.

If there is anything else you need to ask to help diagnose my problem, by all means.

I'm thinking I might need to change the rear diff bushing that mounts to the subframe...since everything else doesn't do the trick.

Two different types and widths of tires have been on the car since the problem started so I know thats not the case.

 

Bump for cliffs

Car not straight

Alignment good

tires good

no damage

 

Check your wheel bearings...replaced both of mine in the rear. Jack each side up and see if you can wiggle your wheel. There's been a few threads about wheel bearings, one created by me (but i never completed the DIY i promised...heh)

I think drsifu and joaquin had a few threads as well about them.

 

From some website

 

Is your car LSD or open diff?

 

I would suggest checking the wheel bearings as well. I have an 04 coupe too and both my rear wheel bearings failed after 70K miles on the car. Dealer replaced mine under my extended warranty.

Another thing i would check is the either the front-left strut or right-rear shock. One of them could be bad throwing off your balance when accelerating and especially hitting bumps at freeway speeds. I had that happen on my old cavalier and hitting bumps on the freeway threw my car into a wavy-crazy movement.

Have you tried checking your swaybar endlinks as well. Just a suggestion since i dont think you mentioned you checked those. I lowered my car and that almost immediately killed my endlinks, but of course you should hear popping sounds if they are broken, which i dont think you are experiencing.

Other things to check:
Bad Lower control arm bushing (probably might actually be this, check front and rears)
Make sure all tires are the exact same front and rear
Tire pressure?

I have Tein H-Techs and it drives straight when accelerating and freeway speeds. It just kind of pulls to the right at freeway speeds but i think its my tire pressure since its only a slight pull.

 

LSD

I checked with the wiggle method before and didnt notice anything. I will look again.

Brand new coilovers are on the car and still have the problem and both front lower control arms are new.

It can't be tires because I had the same problem with my 20s, my oem 18s and still now with my OEM 19s.

All have same tires mounted with even wear.

I'll check the bushings but I'm not sure as to how efficient my inspection could be without the car actually being under load.

 

I would say that the fact that your left rear brake pads are worn is a pretty important place to start. There's a chance that your caliper may be locking up so I would start there.

 

I checked the caliper and cleaned everything. I did a temperature check between that caliper and the other side after some normal driving and both were right around 145-150 degrees.

I'm baffled. I do hear some "loose change" when I go over cracks or road reflectors. I'm leaning toward wheel bearings.

 

im almost convinced its the compression rods or control arm bushings. The compression rods will make a creaking/rattling noise hitting bumps or going over uneven pavement. I'm not sure if a bad one will cause your call to pull but it is definitely worth the check. Check these threads out.

https://g35driver.com/forums/brakes-...oise-help.html

https://g35driver.com/forums/brakes-...otal-crap.html

 

Well I guess your car is actually FWD and you have torque steer! lol

any how jokes aside, good luck on getting it fixed.

 

Update:

Yesterday I had the car up on a lift and saw that the rear diff bushing had absolutley no fluid in it. I even asked Grubbs to take a look at it when it was there the last time and they said it was fine. stupid grubbs...so I'm setting up and appointment today to get it replaced under warranty along with both compression rods and they're also gonna look at wheel bearings.

Funny thing is, everytime I bring the car in, they try to up-sell so much crap thinking im gonna take the bait. It never works each time and they try, everytime