Hi,
My ride is too low. On the rebound down, over a dip, it is so bad that the car front belly rubs/hits the road. I have to change the front upper mounts that are like a dry sponge though still holding a decent thickness.
​​​​​​I have an 04 convertible xkr with R performance, so struts, springs, and others need to be labeled R performance. Problem is that they don't produce any adaptive +R performance springs for the convertible xkr anymore. I assume the R performance means shorter and stiffer springs, and I don't really care for it. Question is, can I use adaptive non R performance springs with adaptive +R performance struts or do I need to change these too? If it's just about the spring height non being R perf (shorter), should it matter for the car to handle well?

I'm really confused because I've read the xkr convertible (x100) need a longer spring than the coupe. Yet R performance has shorter springs. So what do I do with R performance + convertible then? I found springs rated for xkr convertible + adaptive dampers but non R performance. Would these fit with the struts being R performance + adaptive on the convertible?

​​​​​Pain in the butt!! With the discontinuations and all the combinations it gets confusing. I just want the car to not feel like it's driving on ice at this point..any suggestions? It would be nice to, at least, keep the electronic/adaptive feature. But I definitely need the front springs to be changed.
Giving up on the R performance, means changing a lot of other parts. Like hub, bearings (I think) and others I don't even have a list of, specific to R perf.
So I guess but an option, unless these parts are compatible with non R performance.
What's your advices on that xk friends?

Thanks in advance

 

Alexander, maybe you want to change the upper shock mounts first? That can make a big improvement. $140 per pair (polyurethane) from welsh as I recall.

I don't think you said how many miles are on your car, but then as I type I remember you may just want to soften the suspension (or was it cause of bottoming out?). Where I'm going with this is from my experience (changed mine at 80k - no difference) and what I've read, its pretty rare to wear out the spring.

Driving on ice, maybe check the tie rods (easy change). Ah I forget, there is a better first choice for that symptom, read about it here recently. Someone else can recall?

If you get a chance tell us # miles.

John

 

Oh yeah Forgot something obvious. Did you know we published a factory reference to measure both front and rear height. Measured from top of wheel well to center of wheel. Think it should be 15.5 inches front but check the spec to be sure with a search .

 

Yes John. It has 99k. But I have no idea if the previous owner changed anything on the suspension before.
The rebound going so low, the ride measuring at 14 1/2, this points to wrong springs or worn out ones no? Or worn out mounts too.. true..still doesn't explain the very low rebound. I was at 50mph, dip was medium. Happened more than once, car went up, felt like it was taking off, then down slamming on the road! Scary as @#$_&
I've actually changed one tie rod that was cracked. Kept the other one though.

 

A push test, when you push down the car and watch the way it settles back up, wasn't alarming.
It felt stiff. But when driving, it's like taking off and landing hard over dips and bumps. The bumper cover under the car behind the oil cooler, is pretty beat up from all the time it happened. I stopped driving the car on freeways. Frustrating and too scary.

 

Any springs and shocks for the convertible models should fit.Yes you can use Non-R performances springs with R-performance shocks. You will not need to change hub bearings or anything like that. Some people go the other way and install the R-performance shocks and springs on regular cars. They are cross compatible.

That being said, Rockauto sells two versions of the adaptive dampers, one labeled sport and one labeled regular or standard. I imagine sport coincides with R-performance, as the part number on those is different to my regular CATS shocks.

However, rather than investing on shocks and springs, you should measure ride height from the center of the wheel to the fender. On regular cars it should be about 15.8 inches, I imagine R-performance should be one inch less than that. If, you are only one inch lower than that, I would suspect shock mounts and no spring sagging. More than that and I would consider spring sagging.

You said you feel like you are riding on ice, I would first suspect:

• worn upper and lower ball joints
• worn upper and lower control arm bushes
• worn tie rod end
• worn lower shock bush
• worn sway bar links and bushes
• bump stop while you are in there as well

Raise the hood and look at the shock mounts from above. Is the shock not centered? Is the foam crumbling? If yes to either of those two questions, you need new shock mounts. Bad shock mounts alone, I have found, are enough to cause bottoming out, even if they seem to have decent thickness.

Are your front tires worn on the inner edge? If so, bad camber due to worn shock mounts and lowered ride height or improper toe alignment.

I wouldn’t worry about the shock absorbers unless they are leaking or they fail the bounce test. I wouldn’t worry about sagging springs unless your ride height is something like 13.8 inches.

Also, check your tires, they may be worn, or dry rotted, either of those situations would cause you to feel like you are driving on ice.

 

It is my understanding R perfomance handling package was not available on convertibles from factory. This package was a coupe only fitment.

 

Yes the upper mounts are like a hard sponge and crumbling. But there's still thickness. They are however not centered. The lower and arm bushings are ok. The height is at 14.5" for the front.
The car is supposed to have adaptive + R performance, on top being a convertible. I was told convertibles need longer springs.
The main alarming thing is the rebounding so low that it hits the road. Setting new upper mounts will definitely help with height I agree. The new stoppers too will help. But I still wonder if worn out stoppers and upper mounts are enough to let the car touch the floor on rebound. In this case maybe the struts are beat up, or so I thought for a while. Then I've been told it could be the springs.
I don't mind changing mounts and bushings but since being a lot of work I want to make sure I don't need to go back to disassembling everything to change the struts.
Tires are in good shape. I changed the left tie rod since it had a torn bushing. But that didn't change anything.
I guess that my next step is replacing the upper mounts and stoppers like you said.
Thanks a lot. Much appreciated.

 

14.5 inches = worn upper shock mount for sure IME. I've had the same measure 2x. I mentioned it above, better explanation. The factory used foam mounts, most aftermarket replacements are same. Many of us, self included, purchased the poly mounts from Welsh.

its certainly a DIY job. If you go for it and its 1st time, just ask for pointers. We can save you a lot of time.

John

 

I had 2 different Jag dealers look into their system and they told me it was R performance. But go figure they might have meant the R as in xkr..lol..

 

Thanks John. I was told 15.5 for normal height, but 14.5 for R performance. In any case I can't keep on having the bottom touching the road so I'll lift it with spacers if changing upper mounts isn't enough.
BTW yes there's a video from Sam, I think, a tutorial showing how to replace those. Always been nervous having to compress springs... That'll be my next step.
Is Welsh in England? I'm wondering if I'd be better off getting it from a store in the US as everything is disrupted right now. From England, that could take a while to ship huh?

Thanks for your help. Great advices.
Thanks everybody. Be safe.

 

Welsh Enterprises is in Ohio. The owner’s last name is Welsh. If you don’t want to have to go in later, just change everything the first time around. For an extra hard hit on your wallet, consider Powerflex polyurethane bushings. Expensive compared to rubber, but they are more durable. However, the ride may be a smidge more “sporty”. To me, ride quality was not affected, but then again, I am too young for back problems that would make such things more noticeable. Handling does feel a bit sharper.

 

Works for me. As long the ride gets higher and stop hitting the road, I'm ok with anything!!
Besides Welsh, are these ok, they also have the uro and eurospare brands and the stoppers too in the same brands:
https://shop.advanceautoparts.com/p/eurospares-eurospare-shock-mount-l4010144915esp/10758173-P
Will need an alignment after the upper mounts get changed, right?

 

I agree with Baxtor,,,,"R" Performance only came on the XKR Coupe!

Billy Clyde

 

No, only shock mounts worth their weight in gold are the urethane ones sold by Welsh Ent. Even the OE Jaguar mounts are bad. It is just a poorly designed part. I would not buy a Eurospare ones, They may last you a year and a half. The uro would be lucky to make it past a year.

Here's the link to Welsh's shock mounts, just add to cart and have them mailed to you. For a difference in. $5, I wouldn't go buy the foam mounts.
https://www.welshent.com/Jaguar-Uppe...ir-P26376.aspx

It would be advisable to do the alignment after changing the shock mounts. Even more so if changing tie rods, ball joints, and control arm bushings. That being said, new mounts raise the ride height and correct the camber. If the only thing you change is the shock mounts, you can postpone the alignment and survive social distancing without shredding your tires

 

Alexander, that ride height spec might not be right. I never heard of anything below 15 inches in front so I looked this up. See page 44: https://www.jaguarforums.com/forum/a...ok_09_2009.pdf

BTW- be careful with your tires. Last time my mount deteriorated I ran through a pair of tires (inner edge wear) in no time!

John

 

Upper mounts are probably most of it. Replaced mine not long ago with poly from welsh even though the OEM looked fine, not crumbly, everything was centered and only a few years old.

Got the shock assembly out, sitting on the bench next to the new mount and it was half the thickness! What’s worse is once disassembled and with no pressure on them from the spring they expanded back to almost normal within an hour. Dirty trick them looking “fine” on a table and collapsing to nothing when in use.

As for shocks and springs, reality is they can all be used in any car. Yes convertibles had a little different spring rates from the factory but you can put coupe spring in a convertible or other way round. Just don’t mix and match left to right. This is why the aftermarket (Adamesh, Mina) never had coupe and convertible versions.

If your goal is a comfortable cruiser then you might consider regular non-adaptive shocks. You can get 4 for the price of one and the adaptive bit is only on the rebound anyway. Hitch is you would need to convert all 4 at the same time and unplug the module in the boot.

As mentioned, check the control arm bushings while you have it all apart. Poly or not is up to taste, you will find half of people in each camp but new is something we all agree on.

 

Thanks.
I'll order the upper mounts today or tomorrow on Welsh
I could use advise on how to check the coils and struts once they'll be un-mounted.
What did you mean "Dirty trick them looking “fine” on a table and collapsing to nothing when in use"
I don't understand what you meant there.

Thanks a lot.

 

I think he meant that the foam of the shock mounts, when he removed them out of the car, looked collapsed/compressed but that after an hour it had expanded back to the original shape.

 

Yes, that’s right. If I had not had the two sets next to each other right after taking the assembly out of the car I might not have noticed how collapsed the OEM ones really were.