Hey all guide me to finding this problem. At certain times my front wheels will shake like crazy moving the steering wheel left and right pretty hard. This comes and goes. It will happen for 3 to 4 miles then it will be gone for the complete 100 mile trip.

I have had the wheels balanced......The brake rotors are in spec. However when it is shaking and you hit the brakes it shakes even worse. Seems that if you hit a rumble strip or pot hole it seems to go away.

The catch is there is no play in the steering......it is solid as a rock and turnes/handles perfectly.


Could it be a tie rod or ball joint?


Thanks
Brian Felts

 

Hey Brian,

How's the good life?

I guess the first question about your symptom is whether it appeared since the new wheels and tires went on (how about a pic?). I would doubt it has anything to do with your problem as it is intermittant.

Do you have an infrared thermometer to flash temperatures with? I would drive the car until the symptoms appear, and flash the front rotors to see if there is a significant difference in temps. Several XJ8's I have repaired were having intermittant, but very severe front end vibration. Most of the time everything felt perfect, but driving the car for awhile would lead to the onset of the problem: one of the front brake calipers was dragging badly, the rotor warped from excessive heat, and there began the shake. The rotor did not permanently warp, so the symptom was inconsistant.

The XJ6 uses the same caliper, although the front wheel bearing setup is different from XJ8. Still, that's where I would continue the search if all other steering and suspension components feel tight.

The other way you can check for this fault is to drive the car until the symptoms appear, stop and jack the car up before the brakes cool and spin each wheel to see if one is dragging. That may give you an answer.

Restricted flexible brake hoses can cause trapped line pressure and cause a caliper to hang up: opening the bleed screw in this instance will release the pressure, and release the pads. I have never seen this happen on an XJ6 or XJ8 though... it's always a caliper with a damaged dust boot that has rusted from water ingress.

If that's the case on your car, rebuilt calipers are easy to source and not too expensive. Let me know if you find anything else out and I'll help if I can. Best wishes,

Andy

 

I will check the brakes, I was not thinking it could be a caliper. Do you think the bumps are knocking it loose and letting it pull back. The steering is awesome....this just comes and goes on certain roads but pushing the brake does not bring it on.....


Yeah it did it before the new wheels, I thought it was the P4000 tires but with the new ones it is the same. I will get you out some pics......I am sad to say I still have not got to the paint I just sent this 1964 Chevelle SS Convert. home yesterday.



Thanks
Brian

 

Have a look, what I was describing fit the description of most of your first post...except the bumps that is. That wouldn't make much differesnce to the fault I am describing. If something's getting lost in translation, you can always give me a call anytime.

Keep in mind that when you check the front suspnsion on XJ6, you have to jack under the coil spring pan to unload the ball joints and upper wishbone bushings. If you just jack up the front end of the car and not unload the suspension, you won't be able to feel most of the play that might exist at these points.

Nothing wrong with making money, the Chevelle is looking good and the paycheck hopefully looks better.

 

One of my old MGs would be smooth as glass at highway speeds until you hit a bump. Then the steeering would vibrate like crazy, requiring that I slow to 40 mph, where it would smooth out. Back up to 70 mph, all was well....until the next time I hit a bump!

In that case it was worn tie rods, as I recall (it was eons ago).

Just two weeks ago I hit a grapefruit-sized rock while barrelling along a curvy road in my XJR. Long story short, I bent a wheel and injured a tire. You'd think it would vibrate like crazy at all times. It did vibrate, yes, but ONLY at certain speeds.

I don't have any advice over and above Andrew's but thought I'd mention these episodes as additional proof that vibration problems can be a little weird.

Good luck
DD

 

Hey its a good tip........I will look in to what Andrew said and then move to the tie rods. They are really cheap for the car. I am changing oil and plugs as we speak.



Brian

 

On your car specifically, I can tell you that one of the tie rods was replaced and at the time, the other one was in good condition. I think the service records went with the car, you won't have to look too far back to find it.

Worn upper wishbone bushings on earlier XJ6 (XJ40) can produce the same symptoms, although the vibration is usually started by warped brake discs and is then magnified. The severe shake can be intermittant. The later XJ40 and all X300 use a revised bushing that makes this highly unlikely. If they are contributing to the problem, you'll feel the slop when you inspect the suspension.

 

Thank you so much for the help! I am going to get it up on the jacks this evening and I will let you know what I find.

The car has been awesome....Not one single problem. Started every time and kept me cool and warm I still appreciate it! I need to run up some time and look at your toys, its like a playground for me.


Brian

 

Jaguar deserves all of the credit for those cars...except for the clearcoat, that is. Fortunately we both know a guy who can sort that out.

 

Assuming your wheels are aluminum. I would start at the easiest point which would be to make sure your wheels are torqued to the correct specs. Because you're getting the shake happening without brakes applied and it's worse when they're applied would lead me to suspect there's pressure bending the rotor(s). When they heat up it's worse.