Hi,

my cat vibrates at higher speeds.
I did some frequency recording, and found a frequency, that exacly matches the rate of the prop shaft.

There's a procedure of rebalancing the propshaft, which is about 3 hours of work on the jag mechs...but will this be successfull or just wasted money ?

Can I find out if rebalancing is the right thing to ?
Can I make sure somehow, that no bearing or other thing on the prop shaft is broken ?

 

Just fit an used prop shaft they are cheap and looks like you get the whole lot.

JAGUAR X350 3.0/3.5/4.2 PETROL PROPSHAFT | eBay

 

Generally speaking this propshaft thing is due to wear somewhere, bearing, or mounting. Great care is taken to balance these things where they are made, so I would think your problem is a wear problem. However, you've not said how many miles are on the car. This could alter my view.

 

I have 90000km on the clock.. not very much, I guess.
But I don't know everything about the previous life of my car..

I looked into the part catalog of jaguar, there these parts costs more than $3000.
So I try to have a deep look or balancing first, bevor I swap it.

Does anyone know that balancing procedure, the jag mechs use ? Do the balance on the car or do they remove the propshaft ?

 

I haven't seen all that many prop shafts in my life, but of those I have, the balance weights were always of steel welded to the prop shaft at manufacture. So it is not like tyres. Once a prop shaft is made, how can it get out of balance, there is nothing to wear ? On the other hand, bearings can wear out as can the mounts. The X350 shaft is a two-piecer with a UJ in the middle and a "rubber centre bearing", which will no doubt be a roller bearing mounted in rubber. Then at the front and rear, there are rubber couplings to the transmission and the diff. Plenty to wear out there, I would think !

90k kms = 56k miles, so plenty of distance for previous owners to use a lot of welly, and drive at max on the autobahns. Is this an XJR by the way ?

 

I have never heard of a balancing procedure for prop shafts. If it is out of balance, it's either a joint at the end that's bad, or the shaft is bent from somebody jacking on it. I know it sounds incredible that anyone would jack on the drive shaft, but I've had shops do it to me twice over the years.

Google for a gear and axle shop in your area. They will be able to straighten and/or rebalance your shaft pretty reasonably...at least compared to $3k!! It is a specialized service...well beyond the dealer's capabilities. There is a procedure of reinstalling the shaft at a different phase (angle) to try to help vibration. This will only help if somebody installed it out of phase during service. I would think you would know if you had work done on the shaft recently, though.

You can usually see bad joints by lifting the car's rear end and staring at the joints as you rock the rear wheels back and forth. The yokes on each side of the joints should have no play in relation to each other. Any play at all will account for your vibration.

 

I fixed my vibration the last days. I had to replace the propshaft.
It was not out of balance, it was not the bearing, not anything you could see from outside.
It was some kind of internal mounting that got loose... a very rare kind of defect, that hit me ..

 

Hi, I just bought an XJR x350 and it has 50.000KM on the clock. It has never been out of London, so I am assuming it has never driven at speeds over 140km/h. I just drove it to Hamburg, and noticed that between 140 km/h and 240km/h there is vibration , it vibrates in the whole car, and only when the accelerator is pressed down, when I let go of the pedal, vibration disappears. Is it similar to your problem? I am now thinking what to do.

many thanks in advance for any help

 

Does the vibration change while driving at all? I have a vibration around 60MPH when the tires are cold but as the tires warm up on the freeway the vibration seems to go away. I think it's due to the cheap Kumo tires I have on the 20" wheels.

 

Here's my experience on the subject....


https://www.jaguarforums.com/forum/x...ight=rear+diff


Muddy - re your vibration on 20"s


Are you sure its not that the wheels are out of round?? The 20"s are susceptible to bangs/ knocks etc, I had a few on mine that I had taken out.
Its better but not perfect, might be worth checking

 

Yea Jim I checked the wheels out and changed to some brand new wheels also, but kept the same tires since they were almost new. They have been road force balanced rotated, but the vibration is the same. It does go away after a mile or 2 down the freeway. So I believe it is due to the cheap tires when they are cold. My friend has the same issue on his S2000 running Sumitomos. Like the Kumos, they perform well when warmed up and have good traction and are cheap but I guess the tradeoff is some comfort. Next set of tires I will try a better quality tire.

 

Guys, I have brand NEW Kumhos summer tires on 19" original wheels. The vibrations i get are intermittent, it is like as if which gear I am in, and how hard I accelerated. I did 600 mile trip from London to Hamburg, and now the Jag is with my German mechanic. I don't think it is the wheels/tires. But I do think it is the stabilisers, bushes and swaybar. Because at high speeds, it felt unstable, and going from side to side . The vibration only when accelarating hard, as soon as I let go of the accelerator, it went away, and not every time

 

They do need to be balanced. In fact any part rotating at high speed needs to be ballanced!!

Ive had quite a few custom shafts made over the years for cars and 4x4's. The drive shaft makers spin them at speed on a rig that has accelerometers attached to locate the imbalance and will ad some weld or grind off weld to balance them up
This is the same thing a flywheel goes though or even your tyres the only difference is the rig used

The shaft can be balanced on the car using SDD but you need the full kit with the accelerometers not just the mongoose cable

While on the subject there is a rubber coupling at each one of the shaft that wears and cause an imbalance. the part is not listed for the XJ but is the same as the STR. the part number is C2C12747

Cheers
34by151

 

Hi, do You mean the HARDY rubber disk?I was not sure if there was one on this car

 

Yes on each end of the shaft is a rubber coupler

This wears and can cause an imbalance

Cheers 34by151

 

Have they done away with the Hardy Spicer universal joints then?

 

Prop shafts can also be balanced up on a hoist the old way.

Spin to speed, bring a piece of chalk up to just catch the heavy side when it dips towards the floor. Put two hose clamps on the driveshaft with the screws aligned to the opposite side. Spin it up again and find the heavy side. It will likely now to be the screw side. Rotate the screws of each clamp an equal distance away towards the original heavy spot. Repeat spinning and adjusting until the shaft is in balance.

 

No, the coupler is at each end.
IE one at the gearbox and another at the diff
The uni is in the middle

If you look at the JEPC you will see it in the pics but they dont list it as a part. For the XJ they just say replace the whole shaft assembly which comes with the 2 coupler

The Part is the same as the STR.
The STR has a different shaft but uses the same coupler
So just order it for an STR

I guess they think they can milk more money on the XJ owners!!!

Cheers
34by151

 

Thanks so much guys. I got it back from my mechanic, it was awful what he found. All the stabilisers, and rubber bushes were rotten, and he managed only to change the two rear stabilisers as I needed to leave back to UK. They made a world of a difference. The car was now like on rails. I did 160MPH all the way to Holland. But unfortunately when was entering the train through the tunnel at Calais, the cat overheated and burst the valve on the water tank. I hope I didn't cook the engine I will post in another thread. But the stabilisers did solve a lot of the vibration issues, but not perfect yet

 

So this is how the stabilisers look after the very expensive, thorough check at Belgravia Garage here in London