Yesterday afternoon I replaced the brake accumulator (JLM1907) in my '90 Majestic and while bleeding the brakes I examined the rear springs.
I have always felt that the rear of my car sat too low. At some point a PO had the SLS replaced with the factory conversion kit. As I understand, the conversion kit
consisted of the hardware only using the SLS springs(?). I would like to replace these springs with A/M replacements to lift the rear end a bit and improve the ride.
Does anyone have any experience with/knowledge of A/M springs (ex. MOOG part number) replacing the original SLS springs?
BTW, the JLM1907 I replaced yesterday and its replacement were both GM accumulators I bought 5 or 6 years ago and both were stamped ATE.
Thanks,
Roger

 

Many people used the original springs with additional plastic spring shims to get the correct height during the SLS delete.
Most of the SLS springs had a red marking paint strip and many of the proper ones had a green/white marking.

I replaced DOZENS of rear dampers and many people bought the KYB dampers but I never liked the different 'damp rate'. The KYB and the original front had a 'see-saw' effect over bumps that I found unpleasant.

I suppose the KYB in the rear AND front would be the way to go if you want KYB.

The plastic 'shims' come in 2 thicknesses. If I had to use the original springs I used the thicker shims (2 on one end and 1 on the other).
I don't remember if the two would fit better on top or bottom.

The ride height was correct when I got done but I had access to dozens of shims at the shop I worked at.
Some paid the money for the correct Jaguar parts (new springs, mount plate and isolators) but most 'cheaped-out' for the KYB kit.

Jaguar did offer a suspension 'upgrade' to the X300 type cast rear lower arms with the required springs/dampers.
The kit was surprisingly inexpensive but is NLA.

bob

 

Hi Roger,

Depending on how low you think the car is sitting, you may be happy by just replacing the rear shock bushings. The large yellow foam-rubber "donut" spring isolator bushings compress over time, and I've generally gained about 3/8 to 1/2 inch in ride height when I replaced them. They are part 5 in the diagram below. You also want to replace the "Top Hat" bushing, Part 14, and the two cylindrical yellow foam rubber shock bushings, Parts 13 and 15.




The spacers, Part 2, are just rings of hard plastic, and you can make your own from a suitable hard material. McMaster-Carr carries ultra-high molecular weight (UHMW) impact-resistant polyethylene plastic sheet stock in common thicknesses like 1/8 inch, 1/4 inch, etc., and most of the spacers I've seen were in that general thickness range. The spacers can go inside the upper spring support, Part 3, or around the smaller diameter of the lower spring support, Part 4, but there is a limit to how thick the stack of spacers can be or the spring will not be properly constrained by the spring supports.

McMaster-Carr UHMW Impact-Resistant Plastic Sheet

If you have a woodworking router with a circle jig, it's a relatively simple task to rout spacers from plastic sheet. Just cut the outer diameter first, so the center hole for your circle jig pin is still connected to the workpiece when you cut the inner diameter. I use double-sided tape to adhere the workpiece to a sacrificial board while routing. The photo below is from my DIY for making steering rack stiffening bushings, but the principle is the same.




Cheers,

Don

 

Thank you both, The rear end of my car is badly sagged, with virtually no suspension travel - I cant even get a floor jack under the rear of the
car as I once could. After 30 years and 110K miles the springs must be worn out.
I'm of the opinion that the best thing to do is to replace it all. I have two KYB shocks here, with other parts on order.
Then I'll do the front(?).

Roger