I'm in the middle of a front suspension refurb (58,000mi, ride height was 1-1.5in below spec), which includes new shock mounts (Baxtor's), Powerflex bushings on the upper wishbone and stabilizer bar, new tie-rod ends, and new stabilizer bar links. Hoping to to get away with keeping the CATS shocks and lower control arm bushings for now.

I had also planned to replace the springs and ordered the Lesjofors ones. After disassembling one of the struts, I put the old and new springs side to side, see photo below. Old spring free height is about 375mm and the new about 390mm. The coil pitch looks to be the same and the wire diameter is if anything a hair larger on the new spring. Also worth noting is that on the old spring, the top and bottom tails are at the same angular position, whereas on the new they are about 180° off. Since my old shock mounts were pretty much completely disintegrated and others have reported you gain about 1-1.5in by replacing them, I'm beginning to think the old springs may be fine, and the new ones will make the ride too high. Reading what others have posted about aftermarket spring heights, they seem to be all over the place, one post even mentioned a spring having a height of 400mm.

I dread the thought of assembling everything only to find I have to tear it apart again after a few miles of driving (after everything has seated itself) because I bet on the wrong horse.
Anybody have thoughts on what the better bet may be here?
Thanks!

 

The old ones look to be in really good condition, so I'd have probably reused them.

 

Are both sides the same height? The driver side will probably sag more over time, so if they're close to the same I'd stay with the old ones, using the taller one on the drivers side.

 

Curse you, you're wrecking my plan!
I intended to do them one at a time to have one fully assembled side still on the car to serve as a reference for re-assembly if I needed (first time ever doing suspension work on a car).
Your suggestion makes perfect sense though, I'll have to give it thought.
Thanks!

 

Bear in mind that the car will initially 'settle' somewhat on the new springs.

Not sure I'd go to the expense when the originals have only 55K.

 

I would definitely be sticking with originals. Rough calculation, combination of new isolators @ 16mm and new springs @ extra 15mm where damper attaches to lower arm will lift around 45mm at wheel. Would no doubt settle a little but not enough. As far as suspension goes l would consider car to be low milage.

 

Ok, I will bite the bullet and take apart the other side too and ensure that spring is ok as well before putting any of it back together. Means I somehow have to keep track of two sets of upper wishbone bushing shims instead of just one at a time
Thanks all!

 

LMG, somewhere in the back of my mind, I recall that the paint on the springs indicates that RED strip a lowering spring.
Most of the ones I have seen and worked on have YELLOW strips, that would give you the relaxed difference. My new ones are 15 3/8 relaxed. The install height will be the same, as the shock restricts the length they can expand. The strength of the coils and weight of the front will give you how low it drops.

 

was just going to ask if the red stripe might be for lowering springs. My originals have the yellow stripe, don't recall a stripe on my lowering springs but they are aftermarket, so wouldn't expect it. I did notice that DCR Jaguar parts sells the OEM springs for 2000-2005 MY with red stripe and OEM springs for 1997-1999MY with yellow stripe - so the could very well have been replaced with the DCR parts as their aftermarket and lowering springs have no stripes

 

That's a very interesting thought, anybody know if lowered springs were a pre-delivery order option?
Knowing what I know about the history of this car - rigorous service records and 100% OEM as best as I can tell - I really don't see any of the previous owners having had lowered springs fitted without there being some evidence for it, either in the paper trail or tell-tale signs on the car that the work was done.

 

I have an XKR and my original springs with new shock mounts from Wayne are at the correct ride height. My springs have the red stripe.

 

I looked through the 2003-2006 XK8/R workshop manual and below is all I could find on differences in springs:

Shock absorber and spring assembly:
The shock absorber and spring is a coaxial assembly, installed between the lower wishbone and vehicle body. The top spring mounting is attached to the vehicle's inner fender and the shock absorber is attached to a bracket on the lower wishbone. The spring is compressed between the upper mounting and the lower spring pan which is held in position by a circlip attached to the shock absorber. Springs come in various ratings depending on the vehicle's suspension specification The suspension specification also determines the number of packers fitted between the lower spring pan and the spring.
Shock absorbers and CATS (adaptive damping): see section 204-03 Description and Operation. Enhanced Handling Pack An optional enhanced handling pack, which can be either factory or dealer installed, is available for XK coupe vehicles fitted with adaptive damping only. If the handling pack is installed the high performance Brembo brakes and special wheels must also be installed, refer to the Description and Operation sections in 206-03 and 204-04 for information. The handling packs consist of special: Coil springs. Shock absorbers. Adaptive Damping Control Module (ADCM) Increased diameter, front stabilizer bar. Reduced diameter, rear stabilizer bar. Steering rack. Power steering control module.

 

Ok, I did the deed, both struts are out and disassembled.
The driver-side spring is actually 2 mm taller than the passenger-side, so if I'm going with RJ237's suggestion, these would go back in, and in the same location as before. This is what I'm leaning towards doing, but I have a few days to decide as I hadn't realized the risk of the old bump stops being unusable and had not ordered new ones prior to starting the work. The passenger-side stop seems sort of ok, but the driver-side is torn apart and at least 1/3 of it is missing. Now I have plenty of time to clean everything up before the new ones arrive!

To contain the data in one post for easy reference:
At 58,000 miles, my red-striped springs measured 375mm on the passenger-side, and driver-side was 377mm.

 

@LMG no need to wait - check your local Advance auto or AutoZone for equivalent replacement: MOOG PN: K90460 is equivalent to Jag PN: MJA2150BA for the front spring assistors (bump stops). Do not use the bellows they provide - use the existing bellows. I have used these the last 2 times I replaced my upper shock mounts and will use again when I get a set of upper mounts from Wayne

There is a Non-OEM parts list in the XK8/R stickies - link below:

https://www.jaguarforums.com/forum/x...-115180/page2/

 

My I ask why the debate??? The springs are in your possession and the struts are apart. CHANGE the damn springs while it's in this state. Do you look forward to dong it again?? Don't cheap out on the job. my .02 TM

 

The OP might be able to get a refund on the lesjofors and save an unnecessary $$$ spend.

 

That's actually the part I ordered, didn't even consider that it may be available locally. Ah well, lots of other things going on too, so no real harm in waiting a few days on this.
Thanks!

 

I think you may have misunderstood the debate.
Per Baxtor's calculation in the trail, the new mounts may restore the ride height completely, in which case the new springs I have on hand would very likely make the ride too high. The debate has been to try to figure out which option is the most likely to give me the results I want to achieve in terms of ride height, nothing else.

And no, I am not looking forward to doing it again - at least anytime soon - hence the debate on options. That said, I'm not afraid to do the job as many times as it takes to get it right. Jaguar didn't make it too hard for us to remove the front struts, and I bought a nice spring compressor that I intend to keep, so won't have to mess with rentals.

I don't understand what triggered the comment about cheaping out on the job? The new springs were ordered months ago and are not returnable at this point. I suppose if/when the old springs are confirmed to be adequate, I may try to ebay the new ones at some point but that is not a consideration in this at all. It's a sunk cost, moving on.

 

Why?

 

More load fatigue, I guess, since usually it's driver only. I have observed this on a Jag and two other cars I have owned.