I want some help from tire experts. I had a pair of Pirelli P-Zero Nero in 235/40/18 sitting in the garage for a while. So when the rear passenger tire went bald from camber I decided to place the pair of p zeros on my rear wheels the p zeros have about 60% tread. My two front tires are Zexius xi326(came with car) with 75% tread in 235/40/18. Only thing different is tread pattern. All tires were mounted and balanced. Before I got the pirellis rear pair on the steering shaking was minimal. Now it shakes worse. My rotors are not warped. Would getting a new pair of pirellis solve this issue?

 

maybe. but it could be a few things. tires out of balance could be one since that is what has changed. also, are the diameters the exact same between the two?

a likely cause could be a bad CV joint too

 

You should get your tire rebalance.

 

Questions: does it happen while cruising? While braking? At what speed is it experienced? Is it more pronounced while turning? Answers to these will help answer your question.

 

I doubt that its the balance. They were done proffesionally but ill get that checked.
This shaking happens ONLY when I engage clutch to slow down and brake. The faster the speed the more it shakes when I slow down.

 

sounds like warped rotors if it happens while your braking. Why not have it checked out at a shop?

 

Uneven brake pad deposit is your culprit. Go to stoptechs website and read the section on proper bed in procedure. Most people will never put a rotor through enough abuse to warp it. Those that do wouldn't be asking this question. Not that it's a bad question, just that by the time your warping rotors you've already experienced uneven pad transfer.

 

Appreciate it guys...But my rotors are not warped I have already done stoptechs method for uneven brake deposits a while back...The shaking now is most probably from the tires I got pirellis 235 40 18 in back and zexius 235 40 18 in front. Is it because i have different sets of tires front and back?? I dont think that would result in shaking when slowing down..Any input guys

 

no you wont have a vibration in the steering wheel with your tires, so long as your tires are the same brand n model on each axle....now someone did mention balance on the tires, id look into either front end issue, or your alignment if its really wacky which judgin by you saying your tires wore uneven...get an alignment redone, make sure they put the right pressure in your tires too....

 

This isn't necessarily true. You can actually warp your rotors form improperly torqued lug nuts. If the shop that put your tires on didn't torque them evenly then they can warp the rotors after a few heat cycles.

 

have you tried putting the rears on the front? What happens then?

 

Maybe your rims are warped/bent as that is usually the main cause of steering wheel shake. I'd try putting the rears on the front and see how that works as mentioned above.