Hi all, I have a 2003 XKR. It's NZ new with 46,000km on it and has the CATs suspension. It is fitted with 20" wheels and currently has Nexen Nfera SU1 tyres - 255/35 on the front and 285/30 on the rear. I bought the car at 40,000km and it came with these tyres. I have noticed that doesn't feel that comfortable to drive at even the open road speed limit on our rougher roads. It moves around on the road. Hard to describe but lets just say it doesn't inspire confidence to press on.

Any ideas or advice as to what could be causing this less than sure footed feeling. The car is 17 years old, could it be the shocks needing a rebuild? I have replaced all the bushes in the front with Powerflex ones and this has improved the feeling slightly (a clunk sound has gone now). Or is it the tyres. Nexen SU1 tyres are OK but certainly not what I would call high performance tyres. I have run them on my business car, a Mazda 6 wagon and they worked ok on this car. Certainly alot quieter on our disgusting coarse chip tarseal. Any other ideas as to where to look? The tyres have plenty of tread left so don't want to buy new ones on a hunch. Unfortunately the city I live in does not have a suspension specialist with a shock tester so testing the shocks is problematic.

Than ks in advance
Mike.

 

Check the upper shock mount. The Jaguar part is junk, the foam crumbles over time, collapses and creates a lot of negative camber. Look into the upper mount from Welsh Ent in Ohio, best part for the job.

Separately, scary behavior is usually associated with failed rear sub-frame mounts. I am less familiar with the problem, but these mounts seem to deteriorate for some and let the rear sub-frame move around and "help" steer the car. Not a good feel.

For peace of mind, if you disconnect the CATS module in the trunk, all shocks default to stiff. Might be a good way to confirm the system is actually working as it should when plugged in. To my knowledge, only the shock rebound is adjusted with this system. Compression remains constant.

Last would be to reconsider these large 20" wheels, in spite of their incredible look, and move to 18" wheels for more sidewall. The 18" Hydras are known to accommodate the bigger Brembo brakes but beware that not all Jaguar wheels do, e.g. 19" Apollos do not.

Best of luck, keep us posted.

 

Hi, thanks for the reply. A few things for me to check while I've got her up on axle stands.
The upper shock mounts - are these for the front shocks only? I have a full parts list brochure from SNG Barratt and XK's unlimited and they list the foam rubber part. I would buy an upgraded part that doesn't deteriorate.
For the rear subframe I have Powerflex bushes for the Beam Mounting (big bushes mounted horizontally) and the axle brace mounting (mounts the diff to the body). Are these all the bushes I need (have already done the anti roll bar bushes).

Whiles I've got the car on axle stands I'll be doing the following work
Skim all the disks and fit new brake pads
Replace the rear suspension bushes
Replace the brake pedal switch (getting the standard error codes for this)
Remove the drivers seat to allow more room to work under the dash to replace the brake pedal switch. While I have the seat out I'll check all the connections for the seat adjustment as the seat memory is inconsistent.
With access to under the dash I'll wire in my radar detector rather than using the cigarette lighter plug.
With the rear suspension out look at replacing the exhaust from the front muffler back with a less restrictive over axle segment.

Quite alot to do but it doesn't matter how long it takes.

Thanks
Mike.

 

Mike,

That’s quite some “To Do List”

+1 to Fmertz

I’m in construction and I often visit work sites which can be on rough roads. My driving experience of my 99 XK8 is that it’s susceptible to “bump steer” ie when the two front tyres are not on the same level it naturally steers towards the lower side. The X100 was never suppose to be an off road car so suspension set up isn’t made to be an off roader.

If you are regularly on rough roads at speed, your 20” rims are not the right choice.

Cheap test is to deflate them ( Jags typically have two tyre pressure settings - 1 for comfort and 2 a higher pressure for performance). Go for the lower setting to see if this improves your ride. If it’s too “low profile” ie rims hit the ground, then it’s time to think about smaller rims.

For my L322 Range Rover, I ditched the stock 20” rims for 17”. People thought I was nuts to do this on a supercharged Range Rover. But I wanted to tow my dual horse box off road at a decent clip. Needs must. To be fair, on the road you’ll never need a 500bhp big SUV so no loss.

 

Actually I think I know exactly what you mean. Feels like your driving on ice? I changed the bushes, shocks etc and it still felt the same. I thought it was me. I got the garage to change these upper mounts and the problem went away, brb got to find some photos for you.

If you look at the state of these its no wonder it felt like I was driving on ice.

 

David, when I said rough roads I'm not talking unsealed gravel roads. The standard of the roads here in NZ can be lacking. Our state highways outside of the major cities would be, at best, the quality of an English "B" road. The 20" wheels are OK on the roads I drive on but I really notice the difference when I head south to Auckland and drive on the motorway network - soooo smooth..

I want to check and maybe replace the front shock upper bushes. Any recommendations for after market ones that are better than standard?

Also exhausts. I know this subject has been done to death but exhausts like adamesh and xk-parts are from the front muffler back and delete all the mufflers. Would this be too noisy? Anyone fitted the supersprint exhaust - stainless steel with high flow mufflers centre and rear?

Thanks
Mike

 

tifoso, nice to see the work you're doing on your Jag, Love to see photos with the progress as you go. Thanks for posting too.
Cheers
Geoff

 

If you like that sort of thing have you seen FrankC's thread? https://www.jaguarforum.com/showthre...l=1#post697823 plenty of photos on there!!

 

I just bought a set of F Type staggered wheels 19x9.5 and 19x8.5 with 245/40s on the front and 275/35s on the rear then put them on my XF . At lower tyre pressure around 33 psi they ride so nice and as I knew by running them around the 37 psi they do ride firm but not what I would call rough.

 

tifoso,

Going a bit off topic but you did ask about stainless steel exhausts. Here's a link to what I did for my exhaust mod. My supplier DCR's website is listed in my thread and he has numerous options including sound clips.

https://www.jaguarforums.com/forum/x...xhaust-222769/

Check out deuce2000's wonderful work in 2015 in his post #13 using Magnaflow mufflers. His is just plain WOW!.

 

Hi all, I've managed to get a few things done on my todo list. Had the disks skimmed, new pads. I ordered the performance exhaust from Moss Motors in the US and its arrived. Only one part on back order - an exhaust clamp/hanger. With the world (including NZ) pretty much in lockdown I have no idea when it will arrive here. Next job is to replace the brake light switch. I've taken the drivers seat out and given it a good clean with Duraseal products. What a difference, I thought the leather was clean before, now it looks like new - has the nice satin look of new leather.

NZ is in shutdown mode for 4 weeks now so can't work (not much from home anyway) so good chance to work on the Jag. After the brake light switch I'll do the rear suspension bushes. Has anyone else done this? Looks like I'll pretty much have to drop the rear suspension to get at the bushes. This will also give me the opportunity to fit the new exhaust over axle sections. So much to do.

Has anyone else fitted the Moss Motors exhaust? Just the one centre muffler and some tiny resonators built into the exhaust tips. I would have bought from DCR but he never got back to me with a price. I've also got the front shock top bushes (upgraded) on back order but once again, have no idea when they will arrive. Still, its a relatively easy job to replace these.

Cheers
Mike

 

Hi Mike,
Good luck just buying the bushes, I had to buy the complete wishbone and control arms due to not being able to get just the bushes of anyone willing to press new bushed in.See the quote below.Check integrity of rear suspension.
Found control arm bushes worn and rear sway bar links worn.

Work to be carried out.
Supply and fit new upper genuine type control arms. Supply and fit new genuine type lower control arms. Supply and fit new genuine type sway bar links. Road test vehicle.
Sublet rear wheel alignment.

Stabiliser link
R/H upper control arm (Rear) L/H upper control arm (Rear) R/H lower control arm (Rear) L/H lower control arm (Rear) L/H rear sway bar link
R/H rear sway bar link
Rear wheel alignment Labour

Just over $4,000.00 plus between enquiring about the parts and all were in stock withing a week before I had them ordered one part was sold, due to the shut down of our borders I am not sure when that part might be in the country.

 

Sorry but there are a lot of bushes out there for our Jags. Better than the original one too. Look up powerflex. Those are poly bushes that should out live the car. I bought a complete set for my Jag.

Just done an UK ebay search. That resulted in 231 hits!

 

Hi frankc,

Yes, I've bought a complete set of Powerflex bushes for the front and rear suspension. I've replaced all the front bushes and the rear sway bar bushes (the easy ones). Just need to do the other six bushes. My question was how easy (or hard) is it to replace these bushes. Do I have to drop the rear suspension and diff to do this?

Thanks
Mike

 

You will need to dismantle the rear suspension, but the diff doesn't have to be moved.

Member rothwell has done a great writeup (lots of pictures) in his working thread:
https://www.jaguarforums.com/forum/x...9/#post1928458

 

I just redid my front end with power flex but got polyurethane front strut mounts from Welsh. They are awesome.

 

Hi Mike, have to confess I let the garage do mine. Part of a lot of jobs I needed doing. One of the first things I do is change all my bushes over to Powerflex. It was, if I remember right, November time. Too cold etc to do them myself!

Have a look, lots of pretty pictures. Click me to see.

 

Bit of an update on the work I'm doing to my XKR. All the stuff in the interior is finished now.
My son and I set out to change the brake pedal switch expecting it to take a few hours of fiddling around but no - it took about 10 minutes. Because I had skimmed the brake disks and replaced the pads all the caliper pistons were right back in the calipers. To prepare for changing the brake pedal switch I wedged a length of dowel in behind the accelerator pedal and foot rest then pushed the brake pedal all the way to the floor and cable tied it to the dowel. one thing out of the way. After that it was relatively easy but definitely need a person shining a light down from the top and guiding me as I positioned the new switch from below.
As part of the interior work I removed both front seats and gave them a good clean and condition plus the centre console. Also fitted a remote switch and wiring for my radar detector that sits low on the windscreen in the centre.
Next job was going to be replacing the bushes in the rear suspension and this involves dropping the rear suspension so I can also swap the over axle exhaust pipes with the new ones from Moss Motors. Unfortunately due to Covid-19 we're in lockdown in NZ and you can get anything delivered unless it is "essential". Exhaust clamps aren't essential but high end fashion garments are. Plus I have one rear exhaust clamp on back order from Moss Motors but they have closed operations in the US so can't get the part anytime soon. So I'll put off the rear suspension and exhaust work until I have all the parts. Doesn't matter if the car is back on the road I'm not allowed to drive it anyway - only permitted to drive for essential travel like to the supermarket or petrol station. So give it a clean and put it under its car cover for the next few months.

 

Managed to drop the rear suspension (not as hard as I thought it would be) and replaced the bushes. All I used was a large vice, some blocks of wood and a suitably sized socket and all the old bushes pressed out OK. The new Powerflex bushes are in place and the rear suspension is all assembled ready to go back in.

I have a major problem with the exhaust system from Moss Motors. The over axle pipes and rear pipes are all OK and appear to fit but I made the mistake of also buying their front muffler. This part does not appear to have been made to fit a Jaguar XKR. The pipes in and out are larger diameter than standard and don't match up to the new over axle pipes or the front pipes from the flanges. Relatively easy to make this work by expanding the relevant pipes but the major problem is the pipes from the front of the muffler. They splay outward towards the front just like the standard pipes but at the point where they bolt onto the flanges are 45mm narrower than the standard pipes. Very poor quality control on the manufacturers part. Unfortunately I can't go back to the standard front muffler as I have cut some of the pipes off and modified to fit the new muffler. I really need to have the car up on a hoist to give enough room to cut and re-weld the pipes so they fit exactly but I'm doing this in my garage with the car on axle stands. Might be awhile before this job is finished. And still waiting on the new front shock upper bushes. Might see if I can source some from another supplier.

 

Update on the exhaust system from Moss Motors (xks.com). Basically every part they sent me is incorrect. The new performance centre muffler is an old part even though invoiced as the new part. The tail pipes as delivered are two for the LH side (verified by Double S exhausts who manufacture the exhausts for Moss Motors) and now the over axle pipes do not line up with the tail pipes (wrong angle on the final bend dropping the pipe down behind the rear suspension. So here's hoping that Moss Motors will put it right (I want a full refund and will ship the parts back to them). In the meantime my XKR is off the road without an exhaust system and I'm looking for recommendations for an exhaust system that actually fits an XKR and takes out the restrictions in the standard over axle pipes. I'm thinking Adamesh. Has anyone bought one of their systems (over axle and tail section) and fitted it themselves. Do you have to make any modifications to the supplied pipes to make it fit? Thanks