Hi,
I am stumped. I rebuilt everything from the subframe out on my 1988 XJ40. Now it sits around 3" high in front. A local suspension shop thinks I used the wrong springs. I did use new ones when putting it back together. I would be upset if this is true. Anyone have any other idea at all?
Thanks

Added info:
I used springs from a well know supplier. When set side by side with the old ones they sat maybe only a 1/8" taller. I used new Bilstein shocks all around. I didn't see the front sitting so high until I had driven it a mile or so. Could something have bound? Like brand new front shocks?
Thanks again

 

If they were the original springs they would probably have lost some tension or gone soft. It may be that you need to change the rear ones as well.

 

Well. I did change the rear springs also. The car still had the SLS which I removed. The rear seems just fine.

 

After reading a bit I find that things like control arms and sway bar bolts should not be fully torqued without the full weight of the car on the ground. I did not do that. I had it supported with no weight on the suspension. Could that account for a 3" height error/binding after a short drive? I have a hard time thinking I would have even been able to compress springs that would account for the front end being that high?

 

I was just about to ask this. With no weight on the suspension you will have preloaded the bushes. Slacken off all the bolts, bounce the front end a couple of times & see what it looks like.

 

Hi D,

You do need to preload the weight on the control arm and lower shock bushes before fully torquing the fasteners, but there's no way that could account for a difference in ride height of 3 inches.

First of all, are you certain the car is really sitting that much too high? Compare your car with our '93, the red car in the photos in the first post at the thread at the link below. I've replaced all the suspension bushes at both the front and rear ends of this car, but I have not replaced any of the road springs:

https://www.jaguarforums.com/forum/x...garage-128252/


The road springs and subframe Vee mounts are the primary determinants of front end ride height. If your front really is sitting significantly too high, it might make sense if the springs you received were for a 12-cylinder car and have a much higher spring rate than your original springs.

The only other thing I can think of that could cause such a difference would be if the Vee mounts did not make their way back into their correct locations when you reinstalled the subframe, but I don't really know how that could happen since they basically self-align if the rear pivot bushes are correctly mounted.

Below are links to photos of the front suspension rebuild on our '93 in case they may be of any assistance in solving your mystery:

Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page


Please keep us informed!

Cheers,

Don

 

The picture didn't up load with great quality, but this is how it looks.
I also know the springs have blue paint stripes. But, I can not find the spring rate color codes. I think that is what that is?

 

Oh yeah! - somethings not right for sure!
Wrong springs is my call ..

good luck

Larry

 

Yep, the ride height is definitely way too high. If you're certain the Vee mounts aren' the problem, the only other thing that makes sense is the spring rate.

You might search this forum and the archives at the Jag-Lovers XJ40 forum to see if there have been any posts about spring color code. I know there have been many for the rear springs, related to the conversion from hydraulic Self-Leveling Suspensions on the early cars, but I don't know for sure about front springs.

Please keep us informed.

Don

 

What colour code are your rear springs? Perhaps you could match the fronts with the same colour code? btw, I've not seen any mention of blue spring codes for these cars, but there again maybe I just haven't run across them?

Here's an excerpt from ancient post from the 1990's on Jaglover's that refers to the front spring codes, however it refers to an V12 XJS, so take it with a grain etc ..good luck

Larry

 

Good Evening dbeck54,


Did you get the ride height correct? Please advise.


Respectfully,
Brian

 

Yes, the ride is fine. I guess it was just me being dumb. I tightened every thing up with no weight on it. I loosed every thing and ran it over some speed bumps! It is a champ now! Steers and handles very well.