The rear rend of my 87 SIII XJ6 has started to sag badly and I can feel it on the bumps. Looking to replace the rear shocks/springs.


The task looks simple enough. Any brand recommendation for OE style replacement springs?


Lots available for shocks. I'm partial to the Bilstein B6 rear shocks although some have said they stiffen up the ride a lot. I notice the B6 come with new spring retainers. Wondering if these are compatible with the jag factory springs or is it necessary to re-use the old ones.


Any other bushings, collets, etc. that are good to replace while doing the rear shocks/springs?

 

Boge shocks give the OEM ride but don't last.

Bilstein way too hard. See next recommendation.

Koni way too hard. Save the money and bolt a piece of 2 By 4 inside each spring, same thing.

KYB means "Kills Your Back". (not to mention your suspension).

Check the SPAX shocks that come with springs.

 

Shock absorber is an unfortunate misnomer. The Brit term of dampener is much more descriptive.

The springs are for carrying the load ansd deflect as necessary to please the use of the vehicle. Soft wallowy ride vs hard and stiff but good on weight transfer and turning at speed.

Now, unfettered springs bounce and jounce alarmingly. Dampeners dampen the bounce and jounce. More choices here. Equal dampening on bounce and jounce or a bias? Soft or hard by valving configuration. Single tube or twin tube?

I do not pretend to have mastered the concepts. One of the performance magazines I am reading has an excellent description. If any one wants the cite, contact me. PM.

The old jump on the car and see how it bounces is still a rough indicator of the condition of the dampeners. Down, up and stop or up and down a couple of times!!

Tires and wheels fit into the ride/stance/handle equation. Low profile hard tires and stiff springs and shocks and you'll think you are back in the west driving a team from the seat of a buckboard.

Carl

 

Hmm, I wouldn't have thought Boge are all that bad, as Jaguar used to fit them, but others may be better. A lot depends on annual mileage. Don't forget the price for each shock has to be multiplied by 4 to get the final price.

I see SNG Barratt USA and some other UK suppliers sell a "Gaz" shock that has adjustable damping. If you want to maintain the boulevard ride, keep close to OEM shocks as far as possible. I can't remember what ones I fitted it's too long ago ! Boge seem cheapest, with Gaz next. Bilsteins are expensive.

 

After consideration of the above comments and more research on my own, I decided to go for the Gaz adjustable shocks front and rear. I've generally seen good things about these shocks from classic Jag owners and I like the idea of being able to dial in the damping to where I like it.

I'm hoping they last a while. I'll have to post back on how they are after I dial them in.

Any special tools, techniques for rear spring removal? The fronts look straight forward.

 

No special spring compressor needed. A pair of ordinary 'external' type compressors will do the trick. Many auto parts stores rent them.

Cheers
DD

 

Here's a pictorial of rear shock replacement

Rear Shock And Spring Replacement

Cheers
DD

 

As Doug says, no special spring compressor needed. The rears take some time because one has to do four of them, but it's a quite straightforward job for an experienced DIYer. Fronts are an easy swap.

I actually did my rears twice in the 14 years I had the car, mainly because I bought a set of very cheap shocks, (due to lack of dosh at the time), so after only a couple of years they needed doing again. The next time I had a bit more money so put on some quality ones, but can't remember the name now.