I recently purchased (very inexpensively) (2) 3mm rear suspension ride height shims because that size is all that I could find on the Everyday XJ website and I'm wondering the following:

1) are there other, larger sizes?
2) will it ony raise the rear end 3mm (seems logical)?
3) do I just take them and the car to my tire/brake shop and have them installed on the top of the rear springs?

My rear springs seem to be sagging a bit from 18 years of use and the result is that the rear fenders are closer to the top of my tires than the front fenders are. So I thought these shims might be the solution, but I'm having doubts now seeing the height of the shims in person.

Thoughts?

 

The best solution is to replace the springs, isolator and packing pieces. Maybe you can get by doing all but the springs, as the rubber parts have compressed over the years. I have not looked at these parts as my car was refurbished by the prior owner. But the shims are not going to be magic, as you have already deduced.

 

Maybe you are allowed to stack them.

 

If you are having the work done for you, then you will still incur pretty much the same labout cost whether you just fit shims or replace the isolators and springs. The better solution is to change the isolators and springs. Given the geometry of the spring angle relative to the wishbone and the point at which the damper mounts to the wishbone, the effect on ride height is not equal to the thickness of the shim. I once created a trigonometrical model of the rear suspension geometry, but I can't remeber off-hand the ratio of wheel movement to spring movement but it is greater than 1.

 

FWIW...perhaps nothing.....

On the old Ser IIIs the .125" spacers would yield a .375" change in ride height.

I suspect the true purpose of these spacers was to allow the factory to "trim" the suspension while it was being assembled.....and not to significantly alter the ride height. For that, different springs were used according to the build spec of the car.

I agree that, considering the labor involved, replacing the springs would be a better idea. More likely to achieve the desired result....as opposed to experimentation.

One possible choice as a stop-gap, low cost, "there, that oughta do it" solution might be those lugs that you insert (pound?) between the coils of the spring. These essentially expand the spring and lift the body. Not very elegant but, fact is, they've been around for decades and I've seen 'em on many cars. Can't say that I've ever heard of anything bad happening as a result. Not a "proper" repair, though.

Cheers
DD

 

I would expect those lugs to make the ride harder, since they limit spring travel. I do know of one car, not a Jag, that suffered a broken spring using two of the on a very cold winter day.

 

You probably already thought of this...the rear frame carrier bushes (#14 in the picture). I had these replaced on my '95 XJ6 and they restored the rear ride height. I could see and feel the difference from the driver's seat.

 

I didn't measure the change in ride height but it must have been 1/2 to 5/8".

FYI I just had it done at the Jaguar dealer in London, Ontario for about $550.
I'm sure there are some members of this forum who could do this repair themselves...sadly, I'm not one of them (yet???)

 

Thanks for all of the sugguestions, guys. I guess I have a few options to consider when I take on this challenge, which I consider to be a low priority at this time since it's really an appearance issue with me that's been nagging me off and on since I bought the car a little over a year ago. The car rides fine, suspension-wise, as far as I know. Just that little sagging in the back....

Thanks again,
Joe

 

I have the sag in the rear suspension of my '97 X300. I'm going to look into replacing those bushings.

 

Please let us know the results.

 

Upon further review it's way more work than its worth. The amount of complexity in the rear suspension makes it more work then the minor annoyance of the rear end being a little low.

 

Just replaced all suspension bushings, ball joints, coil springs, and spring isolators. Front ride height is correct. Rear ride height is 1" too low. What gives? Is this something I should correct with shims, or go back to the coil spring supplier (JagBits) and question their spring specifications?

 

I've had the same issue, following a front end rebuild, although the cars handling was transformed with new shocks and road springs, the rear end was sitting a little low, I've temporarily corrected this with a product we have here in the UK called "Grayston spring assisters" they come in a few different sizes, I've used these before on various cars and are surprisingly effective, there probably are alternatives to these available in different countries. This winter I will replace the rear springs but as a quick inexpensive fix these things do the job, "Grayston engineering" have a website with info on these, and they are for sale on eBay too. Hope this helps.