Originally Posted by Robert Z

Thanks to this great forum of experts I decided to take on the front end of my 2004 XJR with sport suspension. You see, when I originally purchased this car a year prior, it had this 'clunk' that would appear somewhere in the front right wheel well; only at slower speeds would it be noticeable. I had the car on lifts three times at different shops to check the bushings and all suspension connections,......, each time, all was stated as good. So why, I asked myself, does the front end seem to feel like it wants to 'explode in a million pieces' when I travel over bumps at lower speed?

A broken Arnott shock, that's why. (video enclosure)

My protocol:

1. Position car
2. elevate front end
3. disconnect battery
4. remove caliper/rotor
5. Follow Arnott's youtube video re strut R&R
6. change rotor and pads/bleed brakes appropriately during the procedure in order to avoid air getting into the brake line
7. replace tires
8. reconnect battery
9. lower vehicle
10 cycle motor

I had a parking brake fault appear (?) and then disappear after engaging/disengaging. No other faults.

Problem solved! I can't believe how smooth and comfortable the ride is now,....., like brand new!! I absolutely love it,...., what an unbelievable car,...., I feel spoiled:-).

Sports suspension shocks from Arnott: $1100/pair
Rotors and pads: $250
Labor: 6 hours
Massage of shoulders and back: $50.00

Total: $1400.00

Bye the way, Arnott has made the air connection to the struts a 'Push and Pull' protocol for easy connection; pretty cool.

Luckily the strut mount bolt had anti-seize on it and it came out with relative ease. I am thankful for that.

I still can't get over the power, comfort, and ride in this car,......, next up, my radar is searching for a 2007 Jaguar XKR coupe:-)))

Thanks again for this forum and all the Jag experts and enthusiasts.

Robert

https://www.youtube.com/watch?v=jze8A8KiklQ

Originally Posted by pfred

I am getting ready to replace the rear air shocks with Bilstein units. I have read in previous threads that you should support the "hubs" with jack stands to prevent overextending and damaging the ride height sensor?

Is this required even if you disconnect battery after placing the car on jackstands?

Originally Posted by pfred

I am getting ready to replace the rear air shocks with Bilstein units. I have read in previous threads that you should support the "hubs" with jack stands to prevent overextending and damaging the ride height sensor?

Is this required even if you disconnect battery after placing the car on jackstands?

Originally Posted by pfred

I am getting ready to replace the rear air shocks with Bilstein units. I have read in previous threads that you should support the "hubs" with jack stands to prevent overextending and damaging the ride height sensor?

Is this required even if you disconnect battery after placing the car on jackstands?

Originally Posted by Jagman99R

Hi PFred, I would say yes, as these sensors have a limited range of motion. I did the front springs just to replace the upper control arms heeding the advice of Steve11's post and everything worked just fine. I don't think that it would be any different for the rears as they are similarly regulated by the ecats module. Don't risk destroying your ride height sensors, it is a simple matter just to disconnect one end of them from the lower control arm and continue on with the job. Good luck with it!

Originally Posted by steve11

Tarheal,

I've been hesitating answering this because it can become complex and unorthadox without a WDS, or whatever they're calling it these days.

You can pull off the air spring change without reprogrmming the ASM. You have to deviate from the JTIS though. First, you have to understand the basic operating modes and strategies of the AS system. To begin, the ASM will need to be calibrated (suspension height set) only if:

Any height sensor is removed, then reinstalled
The ASM is replaced
or a height sensor is replaced.
While the ASM is active and powered up.

So, you don't want to do any of these, even though JTIS says to remove the height sensor. The ASM is using non-volatile memory to "remember" the inputs of all sensors when it is in certain modes, or when the battery is disconnected. So, you need to outsmart it and create that situation while you are R/Ring the air spring and when the ASM wakes back up.

Briefly, there are five modes the ASM takes depending on "activity". The modes are:

Sleep mode
Preliminary mode
Post mode
Stance mode
Drive mode

You'll be focused on one of these - sleep mode. The ASM goes into sleep mode 30 minutes after the ignition is switched off and the last door or trunk activity is detected. The entire air suspension system shuts down during this time (enters sleep mode) and, if the car is not used, wakes up on a 24 hour clock to check height. At 24 hour intervals, the ASM makes adjustments in height by measuring the lowest sensor and adjusting dwonward so the suspension is even.

Basically, you want to catch the system before sleep mode. You're going to do that by positioning the vehicle where you will work on it, get it raised off the ground and suspended, then disconnect the battery before sleep mode (sooner than 30 minutes after shutting the engine down). By doing this, the ASM will store its inputs from the height sensors with the suspension fully extended. In essence, you're going to perform the surgery on the air springs while the ASM is anesthetized thinking the suspension is in the full extended position. That is what it is going to remember when it wakes up. If it doesn't see that, you'll need to recalibrate the ASM.

Follow most of the JTIS steps now - depressurize the springs, you can use a floor jack to take weight off the airspring, etc., not removing the height sensors. Replace the air springs, make all connections, make sure the suspension is sitting precisely the way it was before disconnecting the battery. Put the wheels back on so you are ready to sit the car back down on its suspension. Connect the battery, lower the car back on its tires. Start the engine so the ASM moves from preliminary mode to stance mode. This will activate the compressor which the ASM will be demanding to reestablish the original ride height. You should get a "ride too low" restriction message as the compressor needs to fill the reservoir plus the entire suspension. Even If the compressor is strong, this can take a while because the ASM times out the compressor to preserve it, keep it from overheating. It will cool back down to a preset temperature before coming back on. Giv it the time while the engine is idling, and...with luck...the fault ride too low will extinguish and you'll be on your way...hopefully not to the dealer.

Originally Posted by Nalahung

I got two front air struts for 200 USD each, with CATS on them. I managed to replace them on my own XJ8, took me around 1 hour for each side.

Originally Posted by 04vdp

Ok so its all done! This is how I did it, anybody that want to add any corrections please do so below.

First I drove the car around for a bit then turned it off and jacked it up, removed both front wheels and supported the wheel hubs with jack stands.

I disconnected the battery within 30 mins of turning the car off.

Then...



























Then remove the air spring.

Install is the reverse of the removal.

When you are done connect the battery and start the car. Should raise right up!





If anybody is doing the job and want the full size pics just send me a message with your email.