XKR 4.2 - Vibration at speed

XKR 4.2 - Vibration at speed

Author
Discussion

KGL

Original Poster:

5 posts

252 months

Wednesday 12th November 2003
quotequote all
My 2002 convertible has aways suffered an annoying vibration through the steering wheel at speeds in excess of 70/80 mph.The car is fitted with 20" Detroits and, amongst other modifications, was lowered by Racing Green Cars ( fantastic company by the way). It's been checked out countless times by the supplying UK Jaguar along with stories about XKR steering being very sensitive,low profile tyres, car being lowered etc (which I'm told doesn't affect the car) - but all to no avail.
Does anyone have any similar experiences and hopefully some useful advice.

FourWheelDrift

89,634 posts

291 months

Wednesday 12th November 2003
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This is often traced to a wheel balance problem. You can get them checked at any Kwik Fit type tyre outlet.

PlenumPete

96 posts

271 months

Wednesday 12th November 2003
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KGL,

If the dealer cannot solve the problem get it sent back to the manufacturer! A subscriber on Jag-Lovers had similar problems on a brand new XJ, eventually the car went back into the factory's engineering department, where balancing problems were found in the drive train (diff or drive shaft I think), also the wheels and tyres where changed.

Good luck.

avos

115 posts

252 months

Saturday 15th November 2003
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Never ever try Kwikfit, only go to specialized companys for wheel balancing. There is a special procedure to get the balance right, and if not fully respected, it will never go away. There is also a TSB on this issue TSB 204-17. Below is some text regarding this issue:

Workshop Procedure
Note: Obtain the S96 Tire Optimization Form and first fill out the "original tire information" section.

1. Bring tires to proper cold air pressures and take the car on a 15-20 mile (highway) road test to ensure that all flat spots are removed and sufficient tire heating has taken place. Tire heating is extremely vital to the process, it must not be overlooked.

2. Ensure the vehicle is lifted off the ground as soon it returns, to minimize temporary flat spots.

3. A) For vehicles with original factory balance intact - while still warm, remove each wheel. Measure Radial Force variation, do not disturb factory wheel weights. Proceed to step 4.

B) For vehicles with non-factory balance or with a new tire being mounted - while still warm, remove each wheel. Balance the wheel on the Hunter 9700/9712 and measure the Radial Force variation. Perform wheel to tire match mounting here if balancing machine indicates necessity.

4. Record the value of the Radial Force variation (lbs.) on the inside of each tire with crayon, and mark "high point" spot (as indicated by Hunter 9700/9712) on the tire with a hash mark on the sidewall. It is recommended that a permanent paint mark be applied on the inside sidewall as well. This will eliminate the need to identify the "high" spot again if a future repair requires removing the wheel.

The Tire Optimization Form (S96) must be completed and attached to the hard copy of the repair order along with the Radial Force Variation print outs from the tire balancer.

Note: On vehicles with directional tires or different size front and rear tires, the wheel and tire assemblies can only be optimized at their original location on the vehicle. Proceed to step 6.

5. Reinstall wheels as follows:

- lowest value of Radial Force variation on left front of vehicle,

- second lowest value of Radial Force variation on right front of vehicle, third lowest value of Radial Force variation on left rear of vehicle, and greatest value of Radial Force variation on right rear of vehicle.
- However, do not fully tighten wheel nuts. Snug them in by hand to the point where there is no play or wobble between the road wheel and mounting surface.

6. Rotate each wheel so that the previously marked high point is at the bottom (6 o'clock position) and will contact the floor when the vehicle is lowered (for rear wheels, have transmission in neutral and have an assistant hold one wheel stationary while the other is rotated to bring the high point to the 6 o'clock position).

7. Lower the car partially to the floor, so that light to moderate load is placed on each of the wheels.

8. Torque the lug nuts of each wheel to 95 Nm (70 lb. ft.).

9. Road test the vehicle

pddmac

142 posts

268 months

Tuesday 18th November 2003
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Sorry, but you have, by your desire to have that 'racy' appearance, between Jaguar and unfortuantely you, basically it's f***ked up the ride and harshness attributes designed in the car.
As i recall, but stand to be corrected that vehicle was originally launched with 17" wheels (maybe 18's) and we did a study to package 20's, purely on fashion. hey presto now your car vibrates, feels unstable and undamped.
Secondly it's been lowered- well need i say nore
And finally, there is a fundamental design problem with the rag top, inheritted from the XJS, (XK and old XJS share the same platform by the way). Jaguar looked at engineering the problem out, their term 'scuttle shake'i believe but decided not to on cost.

GavinPearson

5,715 posts

258 months

Thursday 27th November 2003
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I'd follow avos' advice. It is absolutely spot on.

If your dealer can't manage to get it right have them call Jaguar Technical Service and see if a Regional Service Manager can help them. Those guys are first class, and get the technical back up from the Engineers and designers of the vehicle.

p_green

291 posts

282 months

Friday 5th December 2003
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pddmac said:
Sorry, but you have, by your desire to have that 'racy' appearance, between Jaguar and unfortuantely you, basically it's f***ked up the ride and harshness attributes designed in the car.
As i recall, but stand to be corrected that vehicle was originally launched with 17" wheels (maybe 18's) and we did a study to package 20's, purely on fashion. hey presto now your car vibrates, feels unstable and undamped.
Secondly it's been lowered- well need i say nore
And finally, there is a fundamental design problem with the rag top, inheritted from the XJS, (XK and old XJS share the same platform by the way). Jaguar looked at engineering the problem out, their term 'scuttle shake'i believe but decided not to on cost.



sorry mate that is a load of arse - the 20" wheel option from Jaguar was fully developed and has been proved through numerous tests to have only very minor effects on the ride quality. there are certainly no "vibrations" or feelings of instability due to the larger wheel option. As for the scuttle shake you mention this is a phenomenon experienced during cornering or over particulerly bumby roads and is in no way speed related.

As some of the others here rightly point out it is more than likely a balancing (have you had new tyres fitted recently?) or and alignment problem. it could *possibly* even be a loose steering column mount but i'd get the other two tested first.

hope this helps.
Piers.

kamal_raza

4,234 posts

251 months

Thursday 18th December 2003
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KGL said:
My 2002 convertible has aways suffered an annoying vibration through the steering wheel at speeds in excess of 70/80 mph.The car is fitted with 20" Detroits and, amongst other modifications, was lowered by Racing Green Cars ( fantastic company by the way). It's been checked out countless times by the supplying UK Jaguar along with stories about XKR steering being very sensitive,low profile tyres, car being lowered etc (which I'm told doesn't affect the car) - but all to no avail.
Does anyone have any similar experiences and hopefully some useful advice.


Racing Green should be able to help as they are one of the very few people who have a Hunter Balancer. This measures radial forces etc...

spice

632 posts

277 months

Wednesday 31st December 2003
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i run a 4 litre xkr on 20 inch detroits with the R handaling pack (2001 car)superb at all speeds.The only car that has the old xjs platform is the DB7 ,xk all new.try putting R springs and dampers on.