The only way to adjust the rear ride height is by altering the spring perch that rests on each shock absorber body, or by buying shocks with adjustable perches.

 

As far as I know you can use spring packers (CBC5435) up to a maximum of three each side, so raise the rear height a little. In hindsight, though, I wished I'd have gone for the height-adjustable Gaz shocks.

 

Do you mean putting them under the springs on top of the perch? That would be doable, I think. Also, is it possible your springs are a bit tired?
Greg

 

Yep, that's the plan. I think it's the cheapest way to go, initially, before shelling-out for the height adjustable Gaz shocks. Maybe raising the rear suspension might bring the nose down a touch, too? Once car is back from the garage I'll get a photo of the ride-height and post it up.

Spring are new Eibach for an Aston DB7, so it could be that they are specified differently to XJS springs, but I can't find any info around that.

 

Does Eibach say they'll work correctly on the XJS?

IMO, spring manufacturers play it fast-n-loose with specs and applications....which is why we see so many ride height issues after spring replacements

Cheers
DD

 

I bought the springs on Ebay, based on what I'd read on the internet around DB7 V12 springs fitting a V12 XJS, but as you allude to, I guess there's a difference between a part fitting and a part working correctly for the application!

The ride height used to look fine before, but I had to change the suspension as a couple of the shocks were leaking and the springs were rusty. I think the car should have a slight nose-down appearance, but at the moment it sits completely level (maybe like an Aston DB7!)

 

I think Jaguar intended the car to sit level...so you might be OK.

If you want a slight nose down appearance...I like it, personally.... lower the front ride height a bit. IMO

Cheers
DD

 

Quick update - the new cage mounts are in and the shimmy seems better. However, I tried some heavy braking, from as low as 20mph, and the car still shot sideways, so guess this is a brake related issue!

 

What year is your car? Does it have ABS?

Sounds like an ABS problem I had on my 1990.

 

Sorry, it's a 1991 pre-facelift V12.

 

Yup, decades ago on a far older critter, I learned that x's rear brake bias will get one sideways or even 180.


AKA, the bootlegger turn. Yank on the hand brake hard. the shine car does the 180. befuddles the revenoooers coming the other way, now!!


Carl

 

The problem I had was the car veering to one side under emergency braking. The reason is that the front ABS sensors get covered in crud, partially old wheel bearing grease, then the wheel ABS signal is weak. Below a certain speed, the signal is too weak to be detected, at which point the system assumes that wheel is locked, and releases the brake.

Braking hard from, say 60, mine would brake nice and straight, until below about 30mph, when it would suddenly veer to the left.

Fixed it by cleaning and adjusting the sensors.

 

Hmm, will give the sensors a clean, if I can, as that's a pretty easy first thing to try. My original issue with losing control of the car under braking was at high-speed, but it also seems to do it under heavy braking from low speed.

Interestingly, after a few trial emergency stops yesterday, it seems to be braking straight and true now, from low speed at least. Not sure I'd trust it to stop me from high speed as yet, though. I've seen some threads around faults with the ABS valve block, particularly after brake-work and bleeding, which is when my problem started. Looks pretty daunting, though.

 

Nope.....still not right. It handles ok if I chuck it into a low speed corner, but seems to feel unstable at speed, even in a straight line, and especially under braking. I'm fed-up with chucking new parts at it so have booked it in with KWE, as they seem to be the experts with these cars.

 

I will be very interested to know what they find. My original list or possibilities centred on a rear axle problem, and nothing you have mentioned since makes me think otherwise. You have all the symptoms of rear wheel steer. Good luck with it, and start saving!
Greg

 

Have you checked the front brake hoses?
I had a collapsed one on mine that caused it to dive to the left.
After replacing them both with braided hoses I had a full system bleed done and it is fine now.

 

Thanks! I've not checked all the things suggested by contributors to the thread, because some, I don't know how to, but have tried all the 'easy' stuff and still no joy. I can't imagine it's going to be cheap, but I'm not getting any enjoyment from the car as it is. It really feels like it's much less than the sum of its parts, if that makes sense:

Manual gearbox conversion
All the AJ6 Engineering tuning bits
Electric fan conversion
Gaz shocks
Eibach springs
Rob Beere cage mounts
Poly bushes in most bits
3.54 diff
New discs, pads & calipers......

List goes on, and it's still a bit of a dog to drive!

 

Worn fulcrum arm bearing! I never managed to get to KWE but fortuitously, a classic jag specialist has just opened near my home, so I took it in there. It's now stable at speed and handles great. There's still some diving under braking, so I guess it was two or more faults causing my problems. Brakes next.....

 

Hi, I'm not far from you in East Surrey and keen to hear of nearby specialists. Can you provide a contact for your Jag specialist. Thanks and good luck with the car.
LeeP

 

Here you go:

https://www.turnerclassics.co.uk/

the chap who worked on my car was 'John' and really knows his stuff.