Hello:

My 1989 XJ6 has already had the SLS delete and was running KYB Gas Adjust shocks, but one was leaking. So I decided to replace both sides with new KYBs. When I took apart the units, both sides had different bumpers(cushions). I had ordered new coil spring insulators, and they worked fine. And I had mistakenly ordered the URO Shock Bushings, which look like plastic discs with a small tube protruding from the center. Or maybe these are correct?

So my question is, can someone tell me what the proper upper "stack" should be comprised of? Will I need to order additional rubber "bumpers"? Do I need to revert back to ones with the metal spacer?

Sorry if I am not being clear, but this setup is new to me.

Thanks for reading.

 

Post some pictures Chris ....I've replaced the rear shocks but still not quite sure to what pieces you refer, there are several "cushions" and "bumpers" in the upper rear suspension area!

Best pics would show what you have now and what the replacement stuff consists of

cheers

Larry

 

Maybe I am wrong, but I think I might know what you are referring to without pictures. Getting the correct upper shock dampers/bushings was a bit of a struggle for me as well. There seems to be two schematic diagrams for rear shocks used without the self-leveling system.

In the first diagram below (part #14) looks like a regular looking damper. But, second image below, part 14, upper damper, looks like a "top hat." I have seen polyurethane versions of the "top hat" damper listed.

Is this what you mean?

 

Hi Chris,

I think Charles is on it. The second diagram he posted is the period-correct one for the XJ40 and the small top hat or cowboy hat bushings, part 14, are the ones that allow the shock shafts to bang against the mounting plates when they fail, causing terrible knocking sounds. The diagram on the left shows the assembly order for the non-self-leveling shocks:




Cheers,

Don

 

Yes! I have Part number 14, the "top hat". So now do I need to revert to the set-up with two cushions per side and the steel spacer? Or could I use what I have (see below) and buy two cushions per side?

I am so relieved you guys understand what I am asking. There seems to be so little out there with regards to this conversion.

I finished up a Lotus Europa last year, and that was a breeze compared to this XJ6, LOL

Thanks for the replies!

 

You need the top hats as well as the two cylindrical disc bushings, one (part 15) on top of the mounting plate (part 7), and one below the top hat bushing (part 13).

Parts 13 and 15 are regular cylindrical yellow foam rubber discs (or poly if that is your preference - I prefer the OE yellow foam type). They ride around the steel spacer tube, part 12, above and below the mounting plate. The top hat bushings fit up into the holds in the mounting plates, part 7. The lower thick steel washer, part 10, is flat. The upper thick steel washer, part 16, is dished, with the concave surface facing upward. When properly assembled, the nut tightens down until the spacer tube comes up through the bushing stack and makes contact with the upper dished washer, part 16.

It is good practice to heavily coat all the contact surfaces of the rubber bushings as well as the plastic spacers, parts 2, with lithium grease. Lithium grease is safe for most plastics and rubbers. Petroleum grease may cause premature deterioration of the rubber bushings. The reason the grease is important is that without it, there is a very high chance you will have dry squeaks from the bushings while going over bumps.

Here are some links to photos and notes that may be helpful:

Jaguar XJ40 Rear Shock Absorbers - Part 1 of 2
Jaguar XJ40 Rear Shock Absorbers - Part 2 of 2

Cheers,

Don

 

There was an aftermarket bushing replacement setup to use the SLS spring retainer top vs the Jaguar OEM 'Except-SLS' spring 'hat'.(part #7)

I forget what company offered the 'conversion' parts but it saved money by not using the recommended replacement part and re-using the SLS spring 'hat'.

I used the conversion kit when customers brought the kit to the shop for the conversion.
The OEM 'non-SLS' parts were more expensive so the kit was popular at one time back in the 1990s.(as well as the KYB dampers)

 

Chris,
When I replaced my rear shock bushings, I did away with the original "top hat" bushing and used two normal looking bushings (i.e. non-top hat) for the shock absorbers. One suggestion: when you look at rear bushings, you might also want to check the health of part number 5 and 15 (both bushings). Mine were all beat up. One company in the UK makes polyurethane bushings for these parts, but I can't think of the name of the top of my head. Of course, polyurethane will last longer but the ride won't be quite as smooth.
I replaced my front shock bushings with polyurethane and have been very happy with how the car has handled since. When I have to replace the rear bushings, I will use polyurethane based on my experience with the front. But, everyone has different opinions vis a vis polyurethane vs. normal.
Charles

 

Chris,
Point of clarification; you need the top had. I used the second bushing for 15!

 

Just for clarity, the large "donut" spring isolators, part 5, should always be replaced when you service the rear shocks, because they compress over time and the rear end loses ride height in direct relation to the compression of the donuts. It's not uncommon to lose 3/8" to 1/2" in ride height, and the sagging rear end is not a good look and changes the suspension geometry.

You should also replace all of the other rubber bushings, parts 13, 14 and 15. The top hat or "guide" bushings isolate the shock shafts from the mounting plates, so they are critical to prevent knocking sounds, and without either 13 or 15 the bushing stack will not be held in proper compression, which could also lead to knocking over bumps.

BTW, the X300s use a revised top mounting plate and do not use the top hat bushings. The late '94 XJ40s like Larry's use the same revised mounting plate, but the parts diagrams show that they use the top hats. Larry - what say you?

Cheers,

Don