XK8 Front Coil Springs
 

Hi guys

Due to a really low front end and some nasty shoulder wear I am looking to re-spring my front end ( I need about 1.7 inches)! I have looked on line and thru the forum and cant seem to find any definitive specs for new front coils. Several sellers have different springs and allegedly different compatibility from 96- 98 98-2002 and 2002-2005. sizes have ranged from 400mm to 347 mm and wire thickness from 16.5 to 13.5 mm! Does anyone have an answer? Mine is a 97 convertible did the coils change from 96 -2002 or for the xkr over the xk8? I wouldn't mind adding an uprated set (XKR?) but just want to know what the 'standard should be? Any help would be appreciated The jag part number is JLM 20706 and seems to be the same for all models 96 thru to 2002 (no sizes given) but i will probably end up with a non jag part as they seem very rare and expensive!

GVS

check out DCR for OEM replacement springs https://www.xk8-parts.com/2016/10/ja...-gallery-page/

Also - since you need to gain height - check for crumbling upper shock mounts and replace with polys - Welsh offers polys for a decent price for the pair.

While you are in there - check and replace bushings as necessary. Plenty of options either OEM or poly to improve ride. I went with a complete set of Powerflex poly's when I replaced mine

G s, I have my original set of 1998 convertible springs sitting in basement. Do you need anything measured?

Btw, I certainly had no trouble finding OEM replacement a couple of years ago. Cost about $100 each.

John

Thank you
 

Awesome would you be able to measure their uncompressed height and the the thickness of the wire spring please? I gues yours would be a little flat but I guess should be somewhere from 380 to 400mm?

thanks

gvs

Just to pass this on, and as Steve pointed out above: the vast majority of ride height issues come from collapsed upper strut mounts. Next is probably the lower shock joint. Once these are replaced, some folks find out the ride height is still not quite where it needs to be, and either shim the upper mount some, or replace the springs. In other words, chances are your springs are fine, and, due to the expense and challenge locating the right part, should probably not be your first target for replacement. As already pointed out, Welsh Enterprise has an updated mount that folks have yet to complain about (check eBay). Folks that replace the mounts with the Jag part commonly do the job again some time later because the parts fail again.

Best of luck, keep us posted.

Coil Springs
 

Hi guys

I thank everyone for their contribution, I intend to replace the upper shock mounts as well as check the lowers and control arm bushings, my thoughts were that my ride height is so low, that reading thru the forum many seem to have had to replace the springs as well, to make up the height and correct the camber. The trouble I have had is locating the correct spring? Lots of places to buy, but the heights vary from 347 to 400mm and wire thickness from 13.5 to 16.5 mm, that coupled with some places not knowing about the difference between the coupe and the convertible has just led me to reach out to see if there is some kind of definitive answer to the coil springs that I should use. I am really grateful for everyone's support. This is my first Jag :)

Yes I will measure 4u. Stand by, probably later 2nite.

John

Measured:
Height 14.25 inches
Coil diameter 14.16 millimeter

Hope it helps. Let us know how you do.

John

spring upgrade
 

Thanks John

That is the third or fourth set of different sizes I now have.

I guess that removes the 347mm ones, yours are 361 mm, the remainder are 380 to 400mm . I guess original stock would be around the 380 mm mark and anything from 14.5mm in wire thickness up!

I need a 45 mm height gain; does anyone know how much new top mounts will give? Mine look like the Jaguar sponge material, but from the top and bottom don't look to have crumbled at all, the bushes all look good as well!

I will start ordering parts!

upper mounts add about 1.5 to 1.75 inches - roughly 40-45mm

Coil Springs
 

Wow thanks Skliimi

that is exactly what i need, I have ordered a set from Welsh so we will see, I have also found a customs suspension place in Kansas that can also make them to your spec based on the original specs ( that he is researching) for $300 a pair!

many thanks

Garry

Coil Springs
 

Hi guys The spring maker CSS has told me they don't have the oem spec data for the xk8 springs in their library, if i can send them an oem example they can recalculate the original spring rate, height etc, is there any chance i can buy a spring from you Johnken and give it to CSS to work on?

yours

Garry

Garry - have you checked with DCR (link below) to see if they have in stock?? The website also shows a replacement spring. Dave is pretty quick to ship out if he has available. Not sure how much it would cost to get them custom made as opposed to these.

https://www.xk8-parts.com/2013/02/xk...guar-jlm20712/

I fitted 2005 XKR springs and shocks to my 96 XK8 back in 2009 with no issues, in addition to a full purple polybush set, no issues but far better driving dynamics.

XK8 springs
 

Hi Sklimii

Hi and thank you for the link, I saw that they have them, I am awaiting postage costs but the custom made set with added spec for my extra weight on the front end (I have the Chevrolet iron block conversion so around 70lbs heavier) I have been told by CSS will be around $298! so very comparable in price, I will need to buy and ship an old OEM spring to them as they don't have the original specs for the xk8 part! it may just work out too complicated and I will go ahead and replace the springs with a standard part!. Although another issue is the vast difference in the size (height) and thickness of the wire in the replacement parts!

yours

Garry

Gary, just noticed your request. Not interested in selling it, but then I'd sure be honored to support the tradition we have here of helping each other out.

Is their testing destructive? How long would they need it for? Maybe I can lend it to you. Let me know.

John

Hi Johnken

Thank-you for the kind offer, I bought some Lesfojors today! We will see how they do then i can send one of mine to CSS, not sure if their testing is destructive!!

yours

Garry

Ok so i finally got around to fitting everything together:

New mounts from Welsh
New Springs from Lesfojors 400mm new height 15.6 inches
New bump stops and gaiters from Rockauto
New Bilstein struts from Autozone
New Powerflex purple upper arms bushing

The ride height has gone from 14.5 inches to a hair under 16 inches ( i expect them to lose a 1/4 inch as i drive it more) and a full inch I would say is from the new springs, the old ones were 14 and just half an inch tall uncompressed, the steering, smoothness of the ride and handling has improved almost beyond measure!
The Powerflex upper arm bushings were easy to fit, and the arms were easy to take off as well, I ended up with a dozen or so assorted shims/washers on top of the Powerflex thick washers. I decided to fit the powerflex washers and restore the shims close to new US spec so 2 thick and 1 thin on each side, drivers side to the front and passenger side to the rear arm. It was a tight fit! I followed the helpful diagram in the workshop manual.
I had intended to also replace my front and rear bushings on the lower control arms but they simply wouldn't budge not with a breaker bar or my 20v half inch Dewalt impact wrench, simply did not move a MM so i had to put it all back together and drive to D & M service center in Universal city, they are going to put the Powerflex bushings on the lower control arms for me, I have used them several times and their service, work and friendliness is first rate, they are also very reasonable although I wait with baited breath what these bushings will cost me!! They also don't mind working on my 97 XK8 or anything slightly unusual. I highly recommend them
I meant to take lots of photos but being on the ground working meant it was harder to do so !!

cant wait to go for a blast in the hill country!

glad to hear all went well. Having recently completed replacing the lower control arm bushings - yes indeed it is a pain!!