Are the B4 Bilstein replacement air shocks correct for an '07 XJR?

My XJR has been sitting (very low to the ground) in the garage since last August. My search for replacement air shocks at that time gave me a headache

So, I'm about to begin repairing it, and will be replacing all four shocks (and various suspension joint and bushings) as I go. I'd like to use the correct "sport" shocks and retain the OE CATS system, but don't feel like spending ~ $5k for "old stock" replacements.

A quick google search shows the Bilstein B4 shocks as replacements, but seems they are generic for 2004 - 2009 X350 - X358. The correct jag shocks for my car (per SNG Barrett):

Rront C2C41354
Rear C2C41346

...which are specific to XJR and to my VIN H16220

Are the B4 Bilsteins correct for my car?

 

When I had a look at this it did indeed seem that what Bilstein were offering was some sort of comprimise between the 'Sport' (red spot) and 'Standard/Comfort' (green spot) units.

 

When Bilstein started selling the B4s both comfort and sport versions were available
The sports for the XJR were in limited numbers.
These have long since run out. I think you will not find a retailer with any more stock.

When I replaced my sport units I managed to get 2 full sets, via 3 retailers.
I would not sell the spare set unless I also got rid of the car im guessing others that have spares will be the same.

Your options now are pay the OEM price, fit comfort units or go aftermarket
Comfort units give a softer ride, aftermarket is in between but you loose the cats

Depending on what is wrong with your old units I may be interested in purchasing them from you

Cheers
34by151

 

Have you regularly checked your spare set to make sure they remain pressurised to 30(?) psi ?(To keep the bladder inflated and prevent it collapsing away from the inside if the shock).

 

Yeah I check them every now and then, no that often as they have never lost any pressure. Each one has a small section of air tube connected to a Schroeder valve

Cheers
34by151

 

OK, you Jag XJR Gurus:

I'm now recalling my headache...(and why Nanny has been sitting in the garage for the last 8 months)

- Is it true that the correct ('07 XJR) shocks purchased directly from Jaguar would be old stock?

Regarding options, if the correct XJR sports shocks are NLA from Bilstein, I may see about having the originals rebuilt

Unfortunately, the R front has already been replaced with an Arnott unit, which I assume is probably a comfort shock. So, I'll probably need a C2C41354 core

Why are parts for these cars such a royal PITA?

- Does anyone have experience with RMT rebuild services? Assume they simply replace the air bladder and top seal? Do they typically replace end joint bushings as well?

- Is the only difference between sport and comfort shocks damper valving?

- Why is there a specific (shock) part number for 2004 - 2005 and 2006 - 2009 XJR's (based upon VIN). Did the damping change for 2006 and later?

- Do the damper internals typically last long enough to make rebuilding worthwhile?

- Assuming new "comfort" B4 Bilsteins are the only ones available, is there any argument in support of simply using the new, non CATS Arnott units instead? They're certainly cheaper, and have a good warranty

 

I have used RMT for rebuilds and was very happy. Not enough time or miles to say they hold up.
It looks like they do replace the bushing at the bottom. Looks new. If you can set the. At on stands you could pull all four and send to be rebuilt. I would source a factory red dot to replace the Arnott. Tell them you want your shocks back.
I think it will be around 1120.00 to rebuild all four. Cannot comment on dampening. Only seen high mileage shocks.
The difference between green and red is the air bladder from what I have been told. Smaller bladder is stiffer. Dampening is controlled by eCats and that part of the shock is the same for XJR and XJ.

 

Thanks Panelhead!

Interesting; assume the smaller (red dot; XJR) bladder provides a higher spring rate (smaller volume of compressed air). The corresponding damper would need to be stiffer; perhaps the CATS system has sufficient control range to compensate

I called RMT. They do not have a (C2C41354) core. so I will begin looking for one

I'm still puzzled by the unique? part numbers for '07 XJR

Oh - I looked up the Bilstein B4 - it lists as compatible with C2C41354 (front), but does not list C2C41346 (rear)
See More Information for BILSTEIN 44069483

And, Arnott apparently now has a "sport" valved? aftermarket replacement, but no CATS, I believe
Link: https://www.arnottindustries.com/par...20_pid204.html

 

I did the online chat with Arnott a few weeks ago about the "Sport" air shock and they seemed to indicated it worked with CATS (no lights on or anything).

 

only partially correct. There is a resistor or other part to trick computer into thinking eCats is available. But the command signal is dissapated as heat and does not change dampening.
I rigged a Suburban to work with Bilsteins with CATS. Only two wires. Put a resistor across them. Burnt a 5 watt quickly. Went to 25 watt was still working when sold. Think is was 22 ohm for the GM system: