Friday afternoon, all hell broke loose in the driver's front of the suspension. It seems that my initial hunch was correct and that the noise I was hearing was structural after all and not a loose fender liner or somesuch.

Of a sudden, the car started wandering and drifting all over the place, the suspension makes a loud knocking noise when even slight bumps are traveled over and the steering wheel pulls hard left and is off-center to the left.

The air suspension functions as normal with no "too low" messages. The car's ride height is normal front to back and side to side.

I would highly appreciate suggestions on where to look first. I went under the car after this happened, with the driver's side supported by a jack stand. I grabbed and shook all of the components of the suspension and they all seemed solidly connected. My guesses as to possible areas of trouble are: ball joint, bad shock. But then I say maybe not to both because it seemed that something was loose for quite awhile and then finally gave out.

 

You need to get the car up on a ramp urgently so a full inspection can be done. Did you check the top wishbones ? It has been known for the inner bushes to seize and the arm snap in two. If this happens, the hub carrier can wander about as it is no longer constrained at the top.

 

+1

That sounds a lot more serious than a suspension bush failing. Ball joint is one possibility. A diagram makes it easier to see the full setup:



In particular check items 1, 2, 5 and 6 for any cracks.

It's often difficult to see structural damage with the suspension under load. The vehicle needs to be supported and the the load taken off the wheel with a second jack.

Graham

 

Get it on a lift ASAP and I can guarantee the issue will be apparent to anyone with eyes.

 

The car is up on a jack stand now. I have thoroughly inspected all components visually and by tugging/pulling on components. Everything seems fine. I am well read and have been reviewing the suspension diagram from the shop manual, and all of the symptoms described there. The symptoms I have been noticing is best described by this, found in the manual:

"Clonk is a structure-borne noise heard as a loose-sounding rattle or vibration coming from the
steering column. Clonk can be identified by driving and turning over cobblestones, rough roads, or
high frequency bumps such as 25-50 mm tall tar strips. Clonk requires a tie-rod load impact".

So, I went to the tie rod ends. They seem to have the normal travel they are supposed to have when I swivel them back and forth. But, the boot on the outer end is ruptured. I understand this doesn't mean necessarily that the end is bad, and I don't believe this is the problem, but it could be. Here is an image of the outer tie rod end boot showing the cracking.

I also performed the test as outlined in the manual for ball joints:

Position a safety stand beneath the front suspension lower arm or rear suspension lower arm to be
tested.

4 . While an assistant pulls and pushes the top and bottom of the tire, observe the relative
movement between the ball joint and the front suspension lower arm. Any movement at or
exceeding the specification indicates a worn or damaged ball joint. Install a new wheel knuckle as
necessary.
Wheel Knuckle (60.25.23)
5 . While an assistant pulls and pushes the top and bottom of the tire, observe the relative
movement between the ball joint and the front suspension upper arm or rear suspension upper arm.
Any movement at or exceeding the specification indicates a worn or damaged ball joint. Install a new
upper arm as necessary. Refer to
Upper Arm LH (60.35.41)
Upper Arm RH (60.35.42) or
Upper Arm (64.25.31) .
6 . Remove the safety stand.

The wheel exhibits no wobbling or play.

I'm becoming increasingly suspicious of the shock itself, or the upper shock mount. I may take it to a local indy for diagnosis tomorrow morning. I'll keep you posted. Additional thoughts welcome.

 

for the swaying and knocking to take place it sounds like the wheel bearing to me. do you have any play when you wiggle the tire while the car on the jack stand?

 

I have checked for play numerous times, Josh, but I did it again on both sides just now because of your suggestion. Put both sides on jack stands, use one hand to lift under tire to take weight off bearings while trying to wiggle with hands under bottom and top of tire/wheel. No play whatsoever on either side.

I pretty much give up. I'm calling Autoscope European Car Care - Dallas, Plano & Park Cities to schedule an appt. right now.

 

Sounds like you need an inspection by a competent professional. A man has to know his limitations.

 

Right Jag XJ8. The appointment's been scheduled. Thanks.

 

Keep us posted

 

Just to share my experience in case it could be helpful to anyone: my knocking noise has been caused by the shock absorber itself, all the wishbones, arms, joints, etc. have been good and firm, but the absorber itself became loose inside. So, after taking it out I was able to move its arm to the sides to some extent.

 

If the car pulls, the wheels aren't pointed straight. Now, any of the anchor points could be at fault, but are your tie rods intact? Have you tried wiggling the steering wheel with the steering unlocked, engine off?

Or wiggling the tires at 3 and 9 o'clock while off the ground?

 

Sometimes the "shake the tire at 9 and 3 o'clock, then at 12 and 6 o'clock" won't detect a bad balljoint, particuarly with the suspension unloaded.

While its up on stands, carefully put a prybar between the control arm and the spindle, near the ballhjoint, and pry up. Do not rip the boot on the balljoint. You should not be able to see movement between the spindle and arm while applying reasonable force.

 

the knocking sound to me could be many things, but the swaying back and fourth can be only certain things. not to disregard the knocking of course but to sway in the matter how you describe to be all over the place I would think would be more serious than some tired ball joints. since its not a wheel barring, maybe your camber got horrible misaligned some how or perhaps the stabilizer bar has some issues. have you inspected it? on my 98 vdp I changed my leaf springs and didn't properly rebolt the stabilizer bar down. my car road walked like crazy. just another idea.

 

Good afternoon. The diagnosis is in, and there are surprising developments.

Full disclosure: my wife drove the Jag last Friday afternoon and came home saying "something's not right with your car, it's wandering all over the place". When I drove it around the block, the steering wheel was off center and all the wandering and pulling and whatnot and I assumed that whatever had been causing the "clonking" up front all this time had finally let go completely. Keep in mind also that I didn't drive it very far for fear that driving it could make matters much worse in that state. SO, I kept searching the front suspension. However when I drove it 20mph and slower the 1.5 miles to the shop, I started to suspect something wrong in the rear due to the ride and handling freakiness seeming to be coming from the rear of the car.

Lo and behold, a rear tie rod assembly is bent! After speaking to my wife after the diagnosis, she said, "well, I did hit a curb at the bank with the rear, but I hardly touched the curb. Your car is that fragile?" So there you have it. I am curious to hear from the mechanic and you guys what you think. Assuming my wife didn't hit the curb "hard", are the rear tie rod in fact highly fragile and under certain load situations prone to bending, or is it also possible that a worn ball joint on the tie rod assy. was shot and made the tie rod unusually fragile?

The mechanic also looked closely at the front and noticed various bushings are worn. He's working up an estimate is supposed to call me back shortly.

 

Hmm. And no rear wheel or tyre damage ?
Anyway the good news is tie rods are much cheaper than alloy wheels !

 

Yes, Fraser, that's my question. How could a tie rod get bent without other components (wheel, tire, control arm(s), etc., not also suffer some kind of damage?

 

its doesnt take much to tweek a tie rod in the rear when YOU HIT THE TIRE THE RIGHT WAY. Take a 4500# car and a curb and what seems like a little bump to a woman in car is actually alot. That being said Ive straightened them with a pry bar and realigned. I know youre on a limited budget and thats what I would do, and recommend If you where here Ide do it for you for $60

 

I plan on running to the mechanic tomorrow morning. I'll keep you guys posted. Thanks all. Brutal, if we were any closer together, I'd make the trip to you for all my repair needs.

 

Jaguar S-Type, X150, X350 Stabilising Link - Rear (C2D5993*) | JustJagsUK.com=

However, I'd think straightening out and retracking would be OK, but it depends on how much it is bent.