I'm going to get some custom rear coils twisted up for my 93 Vanden Plas 4.0 (serial # 671xxx) but I need to know the starting point of stock springs.
So far all I've found is:
free length: 26.7 cm
dia: 13.2 cm (but is that ID or OD?)
approx 10 coils, flat cut both ends

What I need is:
Rate lbs/inch
Installed height
Compressed height

Any help?

 

I replaced the entire rear suspension on my '90 Majestic with all of the parts from the first gen XJ8.
Works perfectly.

 

Roger, love that idea. I'm now keeping my eyes open for that setup.
In the meantime:I swapped in new JLM657 stock replacement coils and the rear sag is cured!. And they were only $90/pr from some Ebay no name. Which got me a baseline to spec custom coils off of.

Measured specs of stock:
5/8 dia wire
6 coils
free height 10.5 inches
flat ground both ends

Won’t have spring rate till I get them tested.

 

I used to install the rear suspension replacement arm 'kit' when I worked at the dealer. The stamped steel arms became NLA and Jaguar offered a complete kit for a while.

Sometime in the early 2000s the kit also became NLA.

Easy enough to assemble your own setup like the X300/X308/X100.

Some info.

 

Bob, can I pick your brains about what came in those kits?
Any bushings? Would have added a lot of labor.
New fulcrum bolts specific to camber adjust?
Assuming NON self leveling car is getting the cast arm kit, did the pre 94 coilspring and spacers and tophat assy transfer over complete?

Historians from this era of hotrodding are getting scarce...

 

The big wood box came with new dampers, springs, upper spring mount 'hats', bushes/isolators, eccentric camber bolts, lower cast arms, etc.

It's been about 20 years since I did this so I really don't remember all the parts in the KIT but I remember that the price was VERY INEXPENSIVE. (like maybe $500 to $700?)
ALL the XJ40 old suspension parts HAD to be returned to the parts dept.

Just find a salvage X300/X308/X100 and get the parts.