Help with suspension diagnosis
Thread Starter
Drifting
Joined: Sep 2002
Posts: 1,614
Likes: 7
From: South Florida
Help with suspension diagnosis
My car feels loose when the rear suspension unloads following a WOT run. It feels like something heavy is shifting left and right. I noticed the problem a few year ago when I changed from runflats to the nitto tires. I had the alignment set to z06 specs, and it was marginally better. I recently replaced the swaybars and shocks. Though the ride quality is a little better at normal speeds, and the cornering feels more solid, the loose feel did not change at all.
I checked the bearings for play, and there isn't any.
I pryed on the transmission mount and there is about 1/4" movement when using a large pry bar.
I pryed on the A-arm bushings and there is maybe 1/8" play when using a large pry bar.
I checked the ball joints by moving the wheel up and down, but they seemed fine. (I didn't pry on the ball joints to look for movement though.)
I moved the wheel left and right to see if there was unusual movement in the tie rod ends. I didn't see any.
So...any suggestions?
Tires are Nitto's in stock size with proper air pressure. Z06 spec alignment.
btw I have new sway's, bushings and shocks.
I checked the bearings for play, and there isn't any.
I pryed on the transmission mount and there is about 1/4" movement when using a large pry bar.
I pryed on the A-arm bushings and there is maybe 1/8" play when using a large pry bar.
I checked the ball joints by moving the wheel up and down, but they seemed fine. (I didn't pry on the ball joints to look for movement though.)
I moved the wheel left and right to see if there was unusual movement in the tie rod ends. I didn't see any.
So...any suggestions?
Tires are Nitto's in stock size with proper air pressure. Z06 spec alignment.
btw I have new sway's, bushings and shocks.
Thread Starter
Drifting
Joined: Sep 2002
Posts: 1,614
Likes: 7
From: South Florida
Indicators are pointing at the tires, the rears specifically. I swapped a set of rear tires and it seemed to stop. I am running Nitto 555s.
I'll check the balance and the rims tomorrow.
I'll check the balance and the rims tomorrow.
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
how much toe in do you have out back?
tires are a biggie but you need to have toe in out back for stability. 1/16th in to 1/8th combined is common.
that's .03 to .06 in each side
i favor the .06
if you're near zero or have any toe out the rear will be very twitchy and unstable feeling.
tires are a biggie but you need to have toe in out back for stability. 1/16th in to 1/8th combined is common.
that's .03 to .06 in each side
i favor the .06
if you're near zero or have any toe out the rear will be very twitchy and unstable feeling.
