Wheel shudder

[DougX]

Has anyone got any suggestions regarding a wheel shudder I am experiencing at the moment. I have had the wheels balance within the past few days but I am still getting a shuddering through the steering wheel. At times it vibrates the whole car. This occurs at 50 to 60 mph. Road surfaces seem to make a big difference. Smooth surfaces tend to be fine, but rough surfaces makes it worse. I have replaced both upper wishbones in the past few weeks, so I know the rubbers are fine. All other rubbers look ok and had an MOT in November with no advisories. So I’m scratching my head to understand what is going on. Any suggestions?

[andypryce]

Have you swapped rears to the front? At least that way you will know if the wheels or tyres are the cause.

[DougX]

I will try that and see what happens.

[davidr]

Maybe a sticky brake caliper causing the brake pads not to withdraw properly and so, as the brake disc always runs slightly out of true, it grabs the disc on the high points so giving a juddering effect.

[DougX]

If I raise the wheel off the ground and spin it, will I be able to tell whether this is the issue?

[DougX]

I have now had all wheels aligned and balanced but the vibration is still there. I have swopped the front to the back and visa versa. Still no joy. I am really at a lost to know what else it could be. Anymore suggestions?

[andypryce]

What a pain. I used to get brake judder on every XJ I owned and eventually decided it was a design issue, rightly or wrongly. However this doesn’t sound like brake judder as presumably it is speed related? You have eliminated an issue with a wheel by swapping them round, so couple of options, firstly swap wheels with someone else if you happen to know anyone nearby, maybe via the club? Secondly get a good independent to go through braking and suspension thoroughly and methodically, the answer must lie there if it’s not with the wheels.

[JimMann]

Hi Doug, I had a very similar sounding vibration on my XKR a couple of years back. Transpired to be an out of true disc on the front axle. This was caused, not by the disc warping or such, but by a build up of corrosion (rust) inside the ventilated part of the discs, so not easy to see and do something about it. Changing the discs cured the vibration, although you will subconsciously think it is still there for a while as "you are looking for it.
Jim

[Andy P]

Hi Doug,
The symptoms you describe could point to worn front subframe bushes.
Part No 2 in the diagram:
https://parts.jaguarlandroverclassic.co ... nd/jaguar/
Also check the rear subframe mounting bushes and engine mounts
Good luck.
Andy

[ptjs1]

Doug,

Those types of vibration can be quite elusive to track down. Some of them you seem to have considered, but suspension bushes can be fine at MoT examination level yet still have enough combined play to set up those types of vibrations.

My suggested list is:

Wheel & Tyre imbalance (I know you've checked, but try over-inflating tyres by 5psi and see if it makes a difference)
Wheel bearing play
Tracking alignment
Track rod end wear
All suspension arm bushes and subframe bushes
Propshaft imbalance
Diff wear and diff mount wear
Brake disc distortion
Gearbox mount wear
Torque converter imbalance (just over 50, is where it will go into top and can strain the torque converter)

There are some things you can do to help eliminate some of the potential items. For example, if it happens between 50-60, try braking at that point whilst continuing to keep on sufficient power. This may eliminate brake disc distortion or front wheel bearings. Also, try going downhill at that speed and putting the car into neutral and see if the vibration continues. This can eleiminate torque converter / gearbox mount issues.


Good luck

Paul

[DougX]

Hi Paul, you have given me a lot of items to check! Some, obviously I have done, others should have been identified at the MOT if there were issues in mid November (I went around with the MOT inspector as he was undertaking the checks). I am going to visit my local independent Jaguar specialist next week and get him to have a look. I will update this forum when hopefully he identify's the issue.

[DougX]

Fault found. The inside front wheel caliper has seized. New discs, pads and refurb caliper needed.

[Andy P]

Glad they found the problem,Doug.
Happy times
Take care.
Andy

[DougX]

Obviously, the offending brake caliper has to be changed, but when I checked my folder of works carried out I discovered that I fitted both front calipers four years ago. I just wondered whether I should change both front calipers, although the offside caliper appears to working fine. I was just thinking that as the garage is going to replace the disc and pads both sides, is it worth changing the caliper?

[Andy P]

Although you don't really need to change the other one it might be a good idea to change it anyway.
I always like to keep everything the same both sides of the car.
But that's just me,annoys the wife no end .
With the old ones,if the garage gives them back to you,you could put them up on eBay or refurbish them and keep them as spares.
Good luck.
Andy