Just had new tires put on her this evening, however I still have a vibration around 50-55 mph. Not bad, but noticeable. Any idea what to check?

Thanks!

 

Okay, I'll say it:


Tire out of balance and/or irregularly shaped.


But what you were trying to say was that you had a vibration and putting on new tires didn't fix the problem, right?


I'd still take a closer look at the balance of the new tires, and move on to take a closer look at wheel bearings. You might have a bent rim or hub, but the tire shop should have noticed that when they did the recent work.

 

Thanks. The vibration has a different feel than before the new tires. I could check the bearings. I'm guessing it would be rear bearings since I do not feel it in the steering wheel.

70 and up it lessens...

 

Ok, going down a hill at 50, I put it in neutral and it is still there. Soooo, I'm thinking(hoping)that rules out the drivetrain. I'll get the wheels Road Force balanced this weekend.

 

+1 on a wheel being out of balance - could be a suspension alignment issue as well, whether front or rear.

 

Yes, Road Force balance first. Then, if the vibration is still present, check your control arm bushings, a notorious weak spot for these cars.

 

Well, you've determined the the vibration is road speed sensitive and not engine RPM sensitive. So you can probably rule out a vibration from the engine itself, motor/trans mounts, torque converter, etc. Anything forward of the output end of the tranmssion.

At any given road speed the wheels, axles, u-joints, driveshaft, differential, and the output end of the transmission are spinning at the same speed with the transmission in neutral as they are with with the transmission gear.....so they're still in question, among other things.

I agree on the road force balancing as wheel/tire vibrations can sometimes manifest themselves in weird ways. With any luck you'll be able to positively identify a wheel/tire problem....which is much easier to deal with than isolating a axle, driveshaft, etc type problem.

Cheers and good luck

DD

 

I've run into a couple different reasons that a vibration won't balance out.

First is a tire with internal delamination. You can likely rule that out, since it happened on 2 sets of tires.

Second is a bent wheel. They can check that as it is spinning when re-balancing...but be sure to tell them to check. Or better yet, stand there and watch yourself. You are looking for a wobble along the edge of the wheel as it spins.

 

I thought this too but wouldn't the vibration change under load as opposed to just cruising in neutral?

 

Yes, sometimes, depends.

For example and u-joint can behave differently under load vs. no load....or depending on the angle of the shaft it is attached to. For example a vibration occuring only as the suspension moves might well be a faulty u-joint responding to the angle of the axle shaft as it moves up/down with the suspension

But something that is bent/damaged or has had a balance weight thrown off ... wheel, driveshaft, axle shaft, whatever....isn't likely to load sensitive.

Cheers
DD

 

Thanks Doug. I am taking her to a Firestone Auto Care center that has a Road Force machine. IF all wheels come out in spec, I'll get them to check out the other components.

 

When I had vibrations from a bad Jurid flexible coupling (the rubber disc between the driveshaft/propshaft and the differential), the vibration was primarily road-speed dependent. I don't remember how much it was affected by load, if at all. The vibration was low-frequency rumble that could have felt like rear wheel imbalance.

Doug has been through his entire driveline recently, so he can offer us a thorough education!

Cheers,

Don

 

Thanks. I will take a look at that when she's up on the lift.

 

Had a similar issue, but with my F250 work truck. Its a 4dr 4X4 with 33 12.50 16 tires on factory rims, What we found was that the shop did not align/check the "run out" when mounting the tires to the rim. This caused the tech to install LOTS more weight to get the tires/wheels to balance. By adjusting the run out they were able to balance with very little wheel weight.
So, check the wheels and see if you have a lot of lead/taped weights on one as opposed to the others.

 

Thanks. Yeah, I'll be at the Firestone Auto center tomorrow and will give them all the details. If they find the wheels are within tolerance, I'll check out the driveshaft & suspension while it's up in the air.

 

What kind of tires did you put on? I've know that cheaper tires like Kumo will make a vibration feel more pronounced when cold. Does the vibration get less as the tires warm up? I'm guessing that you most likely have a bent wheel. A road force balance may help and be able to correct for the bent wheel, but it will likely come back as the tire ages. You may need to try and have the wheel straitened if its bent.

 

Road Force balance did not fix it. Took it to a Jaguar service dealer and rode with the manager. He said it wasn't bad as if I were crazy. Dunno. The vibration is there and he appeared to be hungover. At a loss now.....

 

Been there! When you drive a car regularly you 'tune in' to how it feels. Others don't feel it. In battling vibration issues I've asked passengers "Do ya feel that? Do ya FEEL that?".... and they look at me like I was from a different planet.

It is also possible to become so sensitized that any disturbance feels like a problem...and road surface issues can be mistaken for a fault with the car.

Still, as far as I'm concerned, a Jaguar should be vibration free.

Mere visual inspection of suspect parts (u-joints, bushings, mounts, axles, etc) often does not reveal any fault....especially if the symptom is subtle. Sometimes you have to take things apart to check/measure/test them. This can get get expensive.


You might ask the dealer or other repair shop if they have an electric vibration analysis kit. These are made by Kent Moore and other equipment suppliers. Using clip-on and/or magnetic sensors the vibration frequency and amplitude are measures. This, together with info like tire diameter and axle ratio, is used to determine if the vibration is driveshaft, wheel tire, engine, etc. Very useful BUT the vibration must be significant enough to a significant, reliable reading.

Cheers and good luck

DD

 

You don't say what mileage you're at?

I'm at 63k and had a pretty bad vibration ( noticeable through the steering wheel ).....
I've just replaced front suspension bushes and shocker bushes as well as rear wishbone bushes and shocker bushes too......Its all but gone now!

Have you had the suspension checked??

I still have a little here n there, but having the car up on the ramp and in drive, it looks like a few of the alloys are every so slightly buckled ( not much, but probably at speed enough to make the difference ).....I'll be geting to them shortly.

Good luck in chasing down your issues..

 

Thanks Doug. The Firestone manager, Jamey(Top-notch guy)told me on the road test it was not the wheels. The vibration was too 'fast' as he put it. I still went for the balancing anyway. When he had it on the lift he had someone run it at 50 and he was holding each of the control arms. He said he felt that the bearings were fine but detected a vibration in the differential. He visually saw the driveshaft in motion and said that was fine. All this for $46.00. Again kudos to them!

Now, I noticed on my Carfax, a differential service and flush was performed when the car had 66K miles. That being said, I didn't think it would be that.

The Jaguar service tech thought I was crazy. He thought it ran great. ??

So, I am at square-one.