Excessive torque steer - differential?
 

My car seems to have developed excessive torque steer. Moderately aggressive acceleration kicks the rear end to the left (car goes right). Letting off the gas during cruising causes the rear end to go right. Engine is stock. Car is lowered with TRD springs and sway bars and gets a lot of track time.


Could this be a differential issue? Going to change the diff oil to Motul 300LS to see if that helps. (Now using the regular Motul 300.)



:burnrubber:

What tires are you running? How much air in them? How is your suspension? What size tires? How is your alignment? Diff is probably the least suspicious thing until you've ruled out most everything else.

I get this issue with my winter tires every year

Have you driven it in the cooler weather before?

This is my first season dealing with the skating on the road feel. New rubber isn't as competent :(

I'm hoping they will feel better when temps drop below freezing.

Check tire pressures. All good, same problem? Swap rear tires left/right and see if the problem persists but in opposite directions. If so, bad tire....

Hankook RS4 225/45 17@ 36psi. No recent alignment. I have driven the car under most every condition but this problem only crept up recently. No relation to temperature, although (not surprisingly) wet roads exacerbate the condition. The tires are a coupe years old maybe not as soft as new. The funny thing is that I don't notice it on the track except for accelerating out of the pits.

Torque steer?
What do you mean? Torque steer is usually associated with front wheel drive.
Do you mean understeer?
Oversteer?

Are you sure your suspension is tight. I've had that happen before on another car and a control arm bolt was loose.

If it isn't the main culprit of tires / tire pressure start to look for marks in the suspension pieces. Then maybe progress to alignment.

Check to make sure your rear toe arms are tight. Mine were not torqued properly when I got my last alignment done and I was getting excessive toe changes on acceleration and decel.

A torsen binds under load, so tires or alignment are more suspect.

Rear Toe. I had this issue a couple times. Cruising steady, it would be straight, hands off the wheel. If I gave it gas, it would steer left, again, hands off the wheel. The steering wheel would be straight but the car would turn. The proper term is THRUST ANGLE when dealing with a RWD car. My best guess is my issue came from severe wheel hop leaving stop lights in the rain. Im looking forward to getting better toe arms and trailing arm bushings.

Dont use LS oil in the rear diff! Yes, the car has a LS. But there are NO friction clutches. Its just all gears.

Torque steer = thrust angle(?): Torque from the drive train (accel or decel) pushes the rear end according to right-hand rule - left on accel, right on decel.


Not over/understeer = occurs in straight line.



Western86, et al: Yes I read on line that it could be wear in suspension parts. I am going to have my mechanic check it out. Car has had a lot of track time so would make sense. And thanks for tip on LS oil.



I don't think it is the tires. They are evenly worn - no obvious defects. But I switched ties and haven't driven it since - so we will see.


Thanks to all.

Broken diff is not outside of the realm of possibility but that is the last tire I would want to run in your current conditions. Hankook doesn't even advise storing them at freezing temperatures let alone driving on them.

The Hankooks are off, Winter tires on.