The previous owner of this car put 225/60 x 16" Goodyear Alliance tires on 16" Vanden Plas rims. These tires/rims look great on the car but it has a very stiff ride and there is a vibration around 70 mph that I can't seem to find. At 75 and above things seem to run smooth. I have been told it could be tires, rims, rotors, drive shaft or just about anything that rotates. I have had the tires/rims balance and checked for truing, twice. I am still suspecting the tires but I don't want to do a wholesale swap of the tires if I can track it to a specific rim or tire. An alignment guy told me the typical tire shop may balance the tire but it could still be out of shape or have tread seperation that could cause the vibration. Is there any way to test for these issues, or a specific test a tire shop can do? Or, should I look for some other source

Bill & Gloria Bevan
1994 XJS Convertable, 4.0L

Submitted by bgbevan@earthl… on Thu, 11/02/2006 - 13:07

Bill & Gloria Bevan
1994 XJS Convertable, 4.0L

Thanks for the recommendation. After taking the car to two different tire shops and getting the standard balance, I found a shop that had a "road force" balancer. It costs a little more to balance the tires/wheels but it solved the problem. The vibration is gone.

They actually spin the tire against a roller which creates the same conditions as if it were on the car, and a sophisticated computer system detects balance issues while the tire is under load. On one of the tires, they actually unmounted the tire, rotated it on the rim. then remounted and balanced it.

Submitted by jmcwells@hotmail.com on Fri, 10/06/2006 - 11:38

Bill,

I put yokahoma DB's on my XJS and they are very noisy. I had the alinment checked and that was ut and helped a bit. Now it may take a few thousand miles to eliminate the noise completly but I'm not overly happy with the tire.

Jim

Submitted by bgbevan@earthl… on Fri, 10/06/2006 - 08:23

Follow-up

I have 35 lbs pressure in the Goodyear tires. I took the car to another shop and they re-balanced the tires and told me they were out by 1.5 oz. They did the front pair first and it seemed to eliminate the vibration that started around 68 mph, but still had it at 70 mph. When the rears were done, no improvement. They also told me some combinations of tires and vehicles have vibrations that can only be eliminated by changing tires. In anticipation of this solution I have shopped around for new tires. While I know Pirelli's would keep me in good graces with the "Jaguar Gods", the Yokohama AVS seems to have a lot better overall performance for a lot less $$.

Bill & Gloria Bevan
1994 XJS Convertable, 4.0L

Submitted by bonnettoboot@e… on Sat, 09/23/2006 - 15:39

First the stiff ride, what tyre pressures have you set? Vibrations like this can be difficult to trace, we have a set of "free" rollers which when used with a vibration meter enable us to drive the vehicle in the shop and pinpoint this type of thing. You have to search around for someone who has this capability. Jaguar affectionado and etc.

Submitted by dougdwyer@adel… on Sat, 09/23/2006 - 10:48

Ask if the tires have been checked using a "road force variation" balancer. This would identify a bad tire, but not all shop have that type of equipment.

Doug Dwyer
Longview Washington USA
1995 XJR
1988 XJS