RT/10 shaky at 120+

[DLTARNU]

Hello,

I have a 1999 RT/10 that gets uncomfortably shaky when I go over 120 MPH. It seems to be a problem that came with age, as I had it over 150 a few years back and it was quite smooth.

I'm going to get the tires changed, as they are almost 5 years old now (but with plenty of tread) and get them high-speed balanced.

My car is often stored for long periods of time, and it generally is not on blocks but on the tires for months at a time. They don't seem to have flat spots, at least visually, and at speeds under 120 the ride is quite smooth.

Could the sensation simply be very low grade flat spots from sitting so long that don't appear until very high speeds? Or could it just be a balance issue?

Thanks in advance for your input!

 

[ViperGeorge]

After you change your tires you may want to inflate them to maximum air pressure while the car is parked. Try to roll the car a little every week too. I have an 07 Saleen that also does the same thing but the shake starts at about 80 or so. My Vipers seem fine. There was a TSB issued by Saleen on the issue of flat spotting. They recommend what I suggest above to prevent the problem. To fix the issue they say to drive the car 5 miles or so and then immediately put it on a lift and remove tires for rebalancing (using proper air pressure).

 

[dave6666]

Motor and tranny mounts? Was my problem.

 

[BOTTLEFED]

isn't it kind of ironic that your username is 'unrattled' and your car is having a problem with shaking lol!

 

[dave6666]

isn't it kind of ironic that your username is 'unrattled' and your car is having a problem with shaking lol!

 

[cayman]

Mine smoothes out after 180

 

[dave6666]

Mine smoothes out after 180

Isn't that called liftoff?