The SLS was deleted in my '90 XJ6 prior to my purchase but I now need to address the worn out upper shock bushings. Figured I'd install a new set of Bilsteins as I was having to remove the old shocks to access the upper bushings. Purchased a set of Bilstein B6 rear shocks but they do not contain the ring on the lower shock body which supports the lower spring perch. Also, the diameter of the steel sleeve to fit the lower mounting bolt is smaller. Bilstein part # 24185806. Catalogs from several different vendors list the same part number.

I've seen reference to different SLS delete kits and have no idea what was used in my car but the shock appears similar to that pictured in the attachment (part # CCC6923 / #9). Can anyone explain why my old shocks look like the factory item and the Bilstein replacements don't interchange? Is there a different Bilstein I should use?

 

I am going through the same thing as you. I have a 1989. I got a set of KYBs from Parts Geek, and they had the lower spring perch.

Best of luck with your project.

 

You need shocks with the ring support on a 90MY car. The spring sits on the shock. Only very late model cars use rear shocks without the "ring'. Most folks use KYB's although there may be a Bilstein or Sachs out there too, just not the ones you have.

Larry

 

I'm finishing up a rear suspension rebuild on my '90 Majestic, using KYBs as well.
My rear springs with 113+K miles and 30 years of service, a saggy rear and
mistakes made during previous work causing more damage I even had to replace the spring mounts on my car!
Because of part changes over the years I now have a 100% new X308 rear suspension.!

 

Hi impster,

I just checked Rock Auto and they list the Bilstein B4 part #24018586 as being correct for the 1990 XJ40, but the shock in the photo clearly does not have the ridge to support the spring seat collet. Their photo of the Sachs #170122 appears correct.

The U.S. Bilstein Parts Finder website doesn't even allow Jaguar as a vehicle selection. The U.K. site does, but shows no parts for the XJ40. It seems impossible to fathom Bilstein having discontinued XJ40 shocks, but it appears that may be the case. I'm having the same problem with the Bilstein CATS shocks for my X100 XKR. Here are the links to the Bilstein sites:

Bilstein Parts Finder U.S

Bilstein Parts Finder U.K.

The OE XJ40 shocks were made by Boge. Boge and Sachs are both now owned by ZF, and my impression is that Sachs is continuing to manufacture aftermarket parts for applications for which Boge was the OEM. I was fortunate to get a very good deal on a pair of Sachs for our '93 and they were excellent, with the same smooth ride and great control as the OE Boges. Unfortunately the price on the Sachs has gone up.

XJ40 owners have reported good performance from KYB and Monroe shocks, but I don't have any personal experience with those on a Jaguar, though I have used them on other vehicles with good success.

Cheers,

Don

 

Did you change the springs and go to cast control arms and fit the rear sway bar and monobrace too?

Larry

 

Well, from the replies, it seems I'm sh-t outa luck with upgrading the suspension. Had also planned to add an upgraded front sway bar from Jaguar Specialties but may put that on hold if I'm having to go with stock type shocks such as the KYBs. Don't want to get wild with swapping other items from other models and finding the Bilsteins listed for my car seemed like a great idea until.... Thanks for all the input, folks.

 

That's a really great quesion, Larry! Which reminds me, to anyone considering converting their car to a monobrace, be sure to change your differential oil first, because that job is FAR more difficult once the monostrut is installed.

 

Why not get a set of newer cast iron wishbones and top spring pans/springs and just use the bilsteins that you bought? There is very little extra work involved and a set of wishbones with wishbone tie can be purchased(at least in UK) for less than a cost of a single new bilstein shock? Then you have the option to further improve the ride by adding rear anti roll bar and a monobrace. Both of these completely transform how the car handles and are right there on top of best upgrades possible for a 40.

 

Katar83, tell me more about this swap. Or can you point me to some existing threads that talk about it. I'm on the verge of sending the Bilsteins back but might consider suspension improvements if the price is right. From what car do these parts come from? Am I understanding that this swap relocates the spring so that it's no longer mounted to the shock? Inquiring minds want to know.

 

Parts come from a later 1993/1994 - 40 and/or from even later X300 which shares the same parts so there are plenty of them available. Basically early 40s including yours had the steel pressed wishbones, then these were replaced with cast iron wishbones. With the latter, springs were moved to sit on the wishbones so they are different, I think the top spring pans might be a bit different too, but thats probably the cheapest part. You would normally want to replace springs when replacing shocks and KYB makes great thicker springs for ~$100 per set of two. You'd need a set of cast iron wishbones from a late 40 or an X300, ideally with a wishbone tie that has extra mounts for the rear anti roll bar(your current one doesn't have them). In UK they normally come as a set and can be purchased for ~$100. Wishbone tie is virtually the same in late 40, X300 and even X308. With these parts you'd be able to put everything back together and have a newer suspension.
To add to this, with the new wishbone tie that has the extra mounts for the rear anti roll bar and the newer wishbones you'd be able to mount rear anti roll bar, this can come from at least 4 different models, late 40, X300, X308 or even XK8.
You will also be able to fit in a monobrace to replace individual differential struts, that can come from an X308.
I've paid ~$40 for each, XK8R ARB and X308 monobrace so they can also be purchased cheaply.

What you need is basically something like this(wishbones, tie and rear anti roll bar):



and this(monobrace):

 

Jaguar issued many TSBs and conversion advice.
The cast lower arm and spring kit is NLA from Jaguar but the parts can be sourced and installed into the earlier XJ40s.