Hello all,
I replaced the rear coil over shocks with a set of Woodhead shocks and spring combo from Welshent and now the car sits 1 inch lower than it was before. I spoke to them and it was if I was talking to a wall in addition to total denial. I think that the Woodhead spring and shock combo is softer than what I had originally. I am using 215/70/R15 Cooper tires on the car.
I read somewhere the H&E did some revision to the rear spring setup and the addition of the 25lb lead weights they added up front behind the headlights, when they were trying to control the roll and vibration on their converted cars. How true is that?.
Should I go back to the original ones or should I just disassemble them and use the old springs on the newer Woodhead shocks
Because the rear end is lower the front is up in the air slightly. I can add back the weights behind the headlights or lower the spring pan to get the car level again. I need to drop the front at least 1 inch
Any thoughts?
I will measure the actual ride height sometime tomorrow and post the results here.
[img alt="This is the stance before changing the rear shocks
"]https://cimg7.ibsrv.net/gimg/www.jaguarforums.com-vbulletin/640x480/dscn1464_547f3939afc35f94b4fa04b0cf1af3d246208f0b. jpg[/img]
This is the stance before changing the rear shocks

stance after shock replacement Rear is too low, front is too high

front ride height. the front spring spacers were removed

Rear ride height

 

I think you should add the weights back, they are there to control body vibrations and resonances.

Convertibles are heavier at the rear than coupés because of the weight of the folding top mechanism and also because of the additional strengthening required to the body to stiffenen it sufficiently.

The ride may be lower because the new springs are softer, or because the spring platform on the new shocks, or the distance between the platform and the fixing eyes are different. That is worth measuring carefully. If the ride is OK with the new springs, then either buy some adjustable platform shocks, or adjust the spring platform by welding some spacers onto the shock, like this:

 

Greg: I noticed that you have 3 spacers at the top of your rear spring. Where did you purchase them? Part #? How much did the 3 spacers raise the rear of your car? I inquired about those spacers from Welshent and I was told by the rep that he did not know anything about spring spacers for the rear spring on the XJS. Apparently, you know more than they do because I am seeing them with my own eyes in your photo.
When you say " adjust the spring platform by welding some spacers onto the shock, like this:" Where and what are the spacers welded to? Your photo shows them between the spring and the top plate. Your statement "welding some spacers unto the SHOCK" has me confused.
Thanks

 

I had the spacers made up by an engineering shop. The problem nowadays with the rear ride height is that quite often aftermarket shocks and springs are very different from the factory originals.

Because platform adjustable shocks are expensive, though a great and best solution, and because I had some almost new Gaz's in stock, and because my rear ride height was wrong, I got the spacers for one side and used platform adjustables on the other. The ratio they raise the R/H by is, from memory about One and a half times the spacer thickness.

The spacers can be welded together and then the top spacer ring tacked to the shock top plate, or you can weld some rods that the spacers fit over to prevent them and the spring from sliding out of alignment:

 

FTR, Jaguar does offer trimming spacers for the rear, part number CBC5435. Item #15 in the illustration



These are only about .125" thick, though. I've used them; one spacer makes about .375" difference in height. Maybe a bit less. Wouldn't be practical for gross adjustments, I reckon.

Sanchez, what size tires are you running? They look abnormally tall to my eyes.

Anyhow, if needed, the front can be lowered by removing the factory spring spacers....if they were installed. Again, these are just .125" thick. And it's not a ten minute job

Cheers
DD

 

@Greg: Thanks for the info.
@ Doug: Tires are 215/70/15. These are the same size tires as seen in the photo below before I changed the rear shocks

Notice that the rear is higher in the photo. I will look into the spacers you mention or revert to the old spring and shock setup that I removed. I understand that the OE spring/shock setup for the H&E car was different to compensate for the additional weight in the rear.

 

Yesterday I removed the Woodhead shock/spring combo and replaced them with the ones I had removed . I drove the car around to settle the springs and the result was a 3/4 inch increase in the rear ride height. I am now at 25 3/4 inches from floor to edge of fender well. Not sure what the ride height should be.

 

The Hess card did have a led weight behind the headlamps. It was for vibration but only weighed 5 or so LBS. Here is a side pic of the Foundation's Hess for ref. It is an original car with all stock parts.