Front suspension

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happycat
Posts:58
Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey
Front suspension

Postby happycat » Sun Aug 02, 2015 9:50 pm

I need to try and raise the front of my car,it sits pretty evenly but looking from the side she does seem to slope forward, driving down country lanes the crossbrace is constantly scraping the ground! Getting new springs seems impossible ,ore chance of winning the lottery! Just wondered if replacing the shocks would help give the front an inch or so or if the shocks would make no difference in the height! I've had a look and she doesn't have the standard shocks fitted, they are branded AYB gas adjust and look fairly new although I've owned her for 3 years now. Any thoughts ,suggestions ?

Cheers Cliff
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

davidr

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Re: Front suspension

Postby davidr » Sun Aug 02, 2015 10:04 pm

Hi Cliff,
Most likely reason for the front springs being a bit low is that (like us all!!) they're sagging a bit with age. Underneath the springs are plastic packer rings that increase the ride height. I can't remember the details at the moment and I'm not going out to the workshop to look it up at this time of night but the official way of measuring the ride height is to measure the distance from the bottom of the cross member to the ground. The ride height is adjusted by adding or removing packing rings from between the bottom of the spring and the pan. I don't think that the shock absorbers can affect that.
2 other thoughts
Firstly, are you sure that your springs aren't broken at the bottom? It can be hard to see
Secondly, my strong advice would be to not even think about trying to remove the front springs without the proper tool (which can be hired from the club). It's the only safe way.
Hope that helps
David
XJS FORUM COORDINATOR
1996 XJS Celebration Convertible 2001 XKR Convertible

Previously enjoyed!
1989 XJ-S V12 Coupe. 2006 XJ TDVi Sovereign. 1995 XJ6 3.2. 2013 XF 2.2d. 2009 X Type 2.0d Sovereign estate

oldtimer
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Joined:Thu Jan 19, 2012 3:19 pm

Re: Front suspension

Postby oldtimer » Sun Aug 02, 2015 10:16 pm

It would help if you gave some details of your motor
Springs support the weight and shock absorbers control the ups and downs. The shock absorbers have no effect on ride height There is a specific ride height for the XJ-S I'm sure somebody will be along to tell us what it is and where to measure.

The XJ- S is based on the XJ platform so share many similarities. The sagging front springs is a common problem. It may be possible to add to the existing shims to raise the front but that needs looking into.

I see that David R has already given you a similar answer

davidr

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Re: Front suspension

Postby davidr » Sun Aug 02, 2015 10:41 pm

Maybe another quick check would be to measure the height to the top of the wheel arch and compare those to another car that you feel looks right? Or compare those measurements front to back?
Does the lower sill line run parallel to the ground?
Perhaps if you park the car on level ground, take some photos and post them on here we could give you our opinions if it looks right or not.

happycat
Posts:58
Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey

Re: Front suspension

Postby happycat » Mon Aug 03, 2015 3:28 pm

Hi thanks for your replies,I've had the springs packed out to the maximum already, I'd be surprised if I had 2 broken springs, to look at side on she does seem to slope forward, I can get two fingers between top of tyre and wheel arch, also because she is a convertible it has the crossbrace under the engine bay it is this that seems to hit the ground on uneven surfaces,on a coupe there probably wouldn't be an issue.

Cheers Cliff
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

Brakebuster
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Location:Gloucester UK

Re: Front suspension

Postby Brakebuster » Mon Aug 03, 2015 4:51 pm

sounds like the fronts are fine being that hight over the tyre, but a measurement will confirm

sounds like the backs are too high ??


pictures side on will be best

but as said above, a level sill is the best guide


BB
1989 5.3ltr V12 XJS Coupé FULLY RESTORED
2015 2.2TD Sportbrake in BRG and black leather
1994 3.2S XJ40 in Morocco Red with Doeskin interior

old cars
1999 4ltr Sovereign XJ8
2004 X-Type

happycat
Posts:58
Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey

Re: Front suspension

Postby happycat » Mon Aug 03, 2015 5:03 pm

I'll post some pics by tomorrow,also when I look at V12 equivalent they seem to sit higher.
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

ptjs1

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Location:Kent

Re: Front suspension

Postby ptjs1 » Mon Aug 03, 2015 9:01 pm

Cliff,

Depending on the size of your fingers(!) and your tyres, I'd say the front could be a bit low. I redid all my suspension last year and my ride height as measured at the front subframe is as per spec. At that height, and running 225/55 tyres I'm getting 3 - 4 fingers above tyre to wheelarch.

The gas shocks originally fitted to the XJS can actually impact the ride height because the damping fluid is held under pressure by the gas. This causes a slight lift of the front. However, whenever I've seen an XJS that's low at the front it's been because of sagging springs.

Fit some Eibach springs, Gaz adjustable dampers and enjoy the Jaguar ride again!

Good luck

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

happycat
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Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey

Re: Front suspension

Postby happycat » Tue Aug 04, 2015 3:07 pm

xjs1.JPG
xjs.JPG
heres some pics :D
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

ptjs1

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Re: Front suspension

Postby ptjs1 » Tue Aug 04, 2015 3:42 pm

Cliff,

The rear of the car looks very, very high! What is the measurement from the bottom of the rear cage plate to the ground? What springs and shocks have you got on the rear?

If you think of the swage line normally being straight on the car, then you'll realise that a 3 finger gap at the front wheelarch would normally equal a zero gap at the rear wheelarch because the rear wheelarch shape is lower. You seem to have a gap at the rear. It's much higher than mine at the rear which measures as per spec at the rear cage.

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

Brakebuster
Posts:3145
Joined:Tue Apr 18, 2006 1:17 pm
Location:Gloucester UK

Re: Front suspension

Postby Brakebuster » Tue Aug 04, 2015 5:02 pm

personally , and this is only my opinion

i feel the back is way to high , as i previously mentioned, and that you may have ' underperforming ' dampers on the front allowing the springs to travel their full extent without damping them correctly

first, i would sort the rear height out, and then check the front damper performance/ rate

other than that, what a fantastic looking car

BB 8)
1989 5.3ltr V12 XJS Coupé FULLY RESTORED
2015 2.2TD Sportbrake in BRG and black leather
1994 3.2S XJ40 in Morocco Red with Doeskin interior

old cars
1999 4ltr Sovereign XJ8
2004 X-Type

happycat
Posts:58
Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey

Re: Front suspension

Postby happycat » Tue Aug 04, 2015 9:15 pm

Hi guys
The photos do seem to exaggerate the rear for some reason!I can just about get one finger between the top of tyre and wheel arch, the rear as far as I know is the original set up, it doesn't seem to have been replaced with anything other than OE, the front shocks have been replaced with AYB gas adjust! never heard of them myself, if the front springs are sagging would they be equal I mean would they both lose their strength together,not one be weaker than the other,both side view seem to look the same?
if I didn't have the cross brace it wouldn't so much of a problem,obviousley I cant remove that. :?
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

ptjs1

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Location:Kent

Re: Front suspension

Postby ptjs1 » Tue Aug 04, 2015 10:10 pm

Cliff,

I think the only way we'll know if there's a problem is if you can give us accurate measurements from the bottom of the front subframe and bottom of plate of rear cage to the ground on a flat surface. And also tell us what size wheels and tyres you have.

Cheers

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)

happycat
Posts:58
Joined:Tue Jul 02, 2013 9:52 am
Location:West Molesey,Surrey

Re: Front suspension

Postby happycat » Thu Aug 06, 2015 4:10 pm

Just measured height as requested, front subframe to ground 10cm,rear from bottom of cage 20cm hope this makes sense and there 15inch wheels
1992 XJS convertible 4.0 signal red
2012 XJL Portfolio

ptjs1

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Location:Kent

Re: Front suspension

Postby ptjs1 » Thu Aug 06, 2015 10:20 pm

Tyre size?

Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)


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