Bushes on XJ8 3.2 Sport 2002

[suneernoronha]

Hi,
Just acquired a fabulous XJ8 3.2 Sport 2002 in excellent condition, done 68K Miles.
Drives well, would really appreciate assistance with 6 points:.

1. The suspension is good in general, but I feel it needs to be smoother. it tends to feel rough at times on small bumps. Would it help if all the suspension bushes are changed? If yes, would you recommend Powerflex or Superpro? If none of these two, then which brand? Also, best place online to buy these from?

2. How much should I pay for labour for changing all the bushes on the car suspension, front and rear, complete? I am based in Hendon, London. Any recommendations for a good garage for this?

3. The steering wheel tends to judder/shake when I apply the brake, particularly when brakes are applied at speeds 40 MPH and above. Would this mean new pads and disks?

4. The steering wheel feels a tad less easy to steer that it should. I would like it more free revolving than it currently is. Would this be a big job?

5. When the car comes to a complete stop, the car tends to give a slight onward shake/movement before it is 100% stationary. What is the most likely cause of this, and is it a big job to fix?

6. When the car is in D Mode/Drive, I would like the engine/acceleration to be a bit less eager than it is now, specially when it is at a very low speed/taking off from stationary. For example when I am in traffic, I tend to put in into Neutral as it feels more eager when in drive at very low speeds. Roughly what costs would I be looking at to get this rectified by you?

Cheers.

[GavinPearson]

suneernoronha said:

Hi,
Just acquired a fabulous XJ8 3.2 Sport 2002 in excellent condition, done 68K Miles.
Drives well, would really appreciate assistance with 6 points:.

1. The suspension is good in general, but I feel it needs to be smoother. it tends to feel rough at times on small bumps. Would it help if all the suspension bushes are changed? If yes, would you recommend Powerflex or Superpro? If none of these two, then which brand? Also, best place online to buy these from?

Your problem is most likely the use of non-OE tyres and excessively high tyre pressures. Running the comfort pressures of 28psi all round dramatically improves matters.

suneernoronha said:

2. How much should I pay for labour for changing all the bushes on the car suspension, front and rear, complete? I am based in Hendon, London. Any recommendations for a good garage for this?

I would have the dealer fix the ones that need fixing with OE parts.

suneernoronha said:

3. The steering wheel tends to judder/shake when I apply the brake, particularly when brakes are applied at speeds 40 MPH and above. Would this mean new pads and disks?

This is most likely down to wheel nut torques being uneven and causing flats to be worn on the discs.

suneernoronha said:

4. The steering wheel feels a tad less easy to steer that it should. I would like it more free revolving than it currently is. Would this be a big job?

Yes, it could be a big job with expense to match.

suneernoronha said:

5. When the car comes to a complete stop, the car tends to give a slight onward shake/movement before it is 100% stationary. What is the most likely cause of this, and is it a big job to fix?

Use of non-OE spec brake pads leading to inconsistent friction characteristics at light loads.

suneernoronha said:

6. When the car is in D Mode/Drive, I would like the engine/acceleration to be a bit less eager than it is now, specially when it is at a very low speed/taking off from stationary. For example when I am in traffic, I tend to put in into Neutral as it feels more eager when in drive at very low speeds. Roughly what costs would I be looking at to get this rectified by you?

Cheers.

It is designed to give rapid performance feel and you will not be able to fix it - it's designed in.

Using neutral is a mistake - it will wear out the forward clutch in the transmission. Leave the car in D unless you need to reverse it or your journey has ended.

[NormanD]

suneernoronha said:

2. How much should I pay for labour for changing all the bushes on the car suspension, front and rear, complete? I am based in Hendon, London. Any recommendations for a good garage for this?

Sorry I can't give prices but your best bet as you are in Hendon is to head out allong the M4 and see Tom Lenthall at T L Jaguar. PostCode RG40 4TS Phone [phone]

One of the best Jaguar Specialists in the country
He really knows his Jags and won't rip you off

You are welcombe to name drop if you wish

[Jaguar steve]

Vibration under braking would suggest a warped disc. Providing you can't see a problem and all the bolts are tight there's nothing you can do except replace them along with new pads.

Before you even consider replacing any suspension components I'd suggest you ensure what you have is in good order without any excess movement. Once you are sure of that then have a Hunter 4 wheel alignment done to make sure the geometry is in spec.

You can experiment with tyre pressures. On 16" wheels anything between 26 to 32 on the front and 28 to 34psi on the rear.

One cheap option to soften the ride would be to replace the front anti roll bar with the touring version and remove the rear one altogether. Wheel balance and tyre quality and condition is absolutely critical on the XJ and can affect ride quality if not spot on.

The X308 ride quality on sport suspension is not great anyway IMO, especially if you have larger than 16" wheels on lower than 60 profile tyres. On my previous sport suspension X308 with 17" Celtics it was terrible on anything except billiard table smooth roads.

[Nick M]

Jaguar steve said:

Vibration under braking would suggest a warped disc. Providing you can't see a problem and all the bolts are tight there's nothing you can do except replace them along with new pads.

I see this comment on a lot of forums - brake judder = warped disc. Whle I don't disagree with your comment that brake judder suggests a warped disc, it can also be down to an uneven build up of pad material on the disc, or a bit of corrosion on them, or a pad not moving quite properly in the caliper... Or yes, maybe even a warped disc. But that's pretty hard to do IME.

I had a BMW which had sat for some time not being used nearly enough, and that had terrible judder through the steering. An hour on each of the front corners cleaning up the discs with emery paper, cleaning the calipers and making sure there were no lips on the discs or hard edges on the pads eliminated the problem without needing to replace a single component.

So, before shelling out on new discs and pads it's worth a bit of time to do a proper inspection and clean up to see if that solves the issue or if there really is a warped disc.

[Jaguar steve]

Nick M said:

Jaguar steve said:

Vibration under braking would suggest a warped disc. Providing you can't see a problem and all the bolts are tight there's nothing you can do except replace them along with new pads.

I see this comment on a lot of forums - brake judder = warped disc. Whle I don't disagree with your comment that brake judder suggests a warped disc, it can also be down to an uneven build up of pad material on the disc, or a bit of corrosion on them, or a pad not moving quite properly in the caliper... Or yes, maybe even a warped disc. But that's pretty hard to do IME.

I had a BMW which had sat for some time not being used nearly enough, and that had terrible judder through the steering. An hour on each of the front corners cleaning up the discs with emery paper, cleaning the calipers and making sure there were no lips on the discs or hard edges on the pads eliminated the problem without needing to replace a single component.

So, before shelling out on new discs and pads it's worth a bit of time to do a proper inspection and clean up to see if that solves the issue or if there really is a warped disc.

Unless the OP has a dial gauge and perfect wheel bearings it's impossible to be sure exactly what the diagnosis is.

However discs are effectively self cleaning. Unless they and the pads are so badly worn, contaminated or corroded they are unable to maintain this function any contamination will soon polish off. Until it does the effect will be brake snatch not judder.

Warped discs resulting from uneven cooling after a few hard stops and holding the car stationary on the brakes straight after are a particular XJ problem. That will produce the classic judder felt through the steering or body usually worse under light braking. Back in the day when I was a spanner monkey it was almost unheard of to replace discs even on very hard driven performance cars but new pads went in almost every other service. Now pads and discs are designed to wear evenly together which improves both the self cleaning function and the parts manufacturers bottom line as well as significantly
reducing brake dust pollution in the atmosphere.

Yes it's always worth a clean and a thorough inspection of all the brake components and mounts before parting with any beer tokens but I'll bet a internet pint in the case of a juddering XJ the discs - even if they are OE quality ones - are bowed like bananas.

[Nick M]

While discs are self-cleaning to a degree, they do rely on an even transfer of pad material onto the discs to work properly. If that doesn't happen then you can get the juddering through the steering because it's massively unlikely that it will be equally uneven on both sides (of each disc, and on each side of the car). I know, because I've had this happen on road as well as track cars, where I checked disc run out and found there was no warping. So don't be drinking your internet pint just yet

So. I'm not ruling out heat-soak after repeated heavy braking as a possible cause, and I'm not trying to disagree with your experience or turn this into a pissing contest, but just trying to suggest alternative reasons for a common problem, and perhaps also a cheaper solution than having to replace discs and pads

[Dodsy]

Juddering most often is caused by localised hardening of the disk caused by coming to a fast stop then sitting with the brakes on. The pads heat up the disk and either deposit an uneven amount of pad material or in the worst case cause that piece of the disk to harden. In either case the result is that as you brake every time that part of the disk goes under the pad it grabs more than the rest of the disk and you get judder.

I have had some success in the past with using hard braking to clean up the disk. So get up to a good lick of speed then brake hard down to crawling speed, then speed up and do it again a few times. Its worth a try but you have to brake hard. Sometimes the bad part of the disk will wear away but that will take many 000's of miles and rely on you not cooking the disk again. SO when you pull up from a reasonable speed use the handbrake.

http://www.stoptech.com/technical-support/technica...