I thought that the purpose of supporting the hubs is to eliminate the need to disconnect the height sensor , preventing the lower control arm overextending the sensor during repair and damaging it. If disconnecting it works, that's easier.

 

I thought the purpose of raising the hubs was also to have a set height that you could return the hubs to after the repair. In this way, the sensor would pick up where it left off, and adjust to the proper height.

 

Special to Oldmots & Amcdonal,

You are both right. The objective in the whole air spring R&R procedure is complete the job without, 1. offending the suspension God or 2. damaging the "ride height sensor" RHS.

To accomplish item 1. you must set the exact position of the hub to a level you know you can duplicate and disconnect the batt.- all within 30 min of turning off the ignition and closing the door.

To accomplish item 2. you must not allow the suspension to be hyper extended with the RHS connected. Or you may disconnect the RHS link and hyper extend all you need to.

When you have installed the new shock, reconnected the RHS and returned the hub to the exact height it was at batt. disconnect, you simply reconnect the batt.
This awakens the suspension God unaware that you have been mucking around in his kingdom and all have to do is mount the wheel and let the jack/lift down.

 

Fabulous pics 04vdp. Thank you for this great follow-up to Steve11's strong technical write-up. I had to carry out this procedure on my '04 XJ for the right front unit and I made an observation that I'd like to share so that someone else could move through it a bit faster than I did. First, it seemed clear to me that your pics were of the right front unit ( which was exactly where I was), so I looked to match EVERYTHING but I could not find a height sensor anywhere. And adding to the confusion, I called the dealer and asked if there was a listing for one on the right front and they said there was. I looked everywhere and finally decided that there was not. I proceeded with the job precisely as outlined by you and Steve11 with a perfect result. I did look at the left front unit and there is a height sensor there just as you had pictured.
I hope this helps someone else who is in the same situation as I was today. Thanks again!

 

The RH front sensor was deleted from VIN G26873.

 

I just replaced the right front air shock with an Arnott unit. Everything went according to plan except that the new unit does not seat all the way up the tower. I can barely get the 4 nuts on. I initially thought I would drive it around awhile to let the weight of the car drive it home. I'm having 2nd thoughts about that.

Anybody had this problem? Should I start over.



BTW, there was no ride height sensor at this corner as mentioned by U102768 and SleekCat.

 

Maybe the studs are tweeked at the top, it should full seat. They can tend to grab the threads through and lock going through the body mount, and no only the early xjs have 4 sensors they switched and at 1 time there was a bulletin to remove and program so if yours is in the vin for having 4 maybe it was taken off.

 

Okay, here's the deal. The Arnott air spring ships with new nuts for the 4 studs. These huts were installed at Arnott and threaded all the way down to the base of the stud. I did not notice them and installed the air spring with them in place. Consequently the air shock would not fully seat in the shock tower. My bad, my back, do over. All is well now.

BTW- the Arnott studs are ASA not the 13 mm studs on the OEM part.

 

This may seem elementary: I noticed that the upper mounting studs on the Arnott unit were shorter than the original studs but they were sufficient. But there was one more thing- the nuts supplied by Arnott were tight enough that I had to get a wrench to remove them. I remember thinking to myself that if they were the same length as the original studs that it would be easy to make the mistake of installing the unit without removing the nuts. Is it possible that you installed the unit without removing them? If you re-used the original nuts at the top, this could be the issue. One other note- if you have to remove the unit, I would suggest taking a pair of Vise-grips and tightening the air hose connector ( mine was loose-something I failed to realize until I had the unit installed and it was not easy to tighten at that point). I hope this helps.

 

SleekCat,

Thats exactly what I did.

 

Tarheal, were the air springs for your XJR the same part as for an XJ8? I have the XJR and may need the Arnott replacements, but read that they were for Comfort ride, not Sport suspension. Any thoughts?

Thanks,

Todd

 

Whoops, I scrolled down the page on their web site and found them. Please disregard.

 

Wow, good call. I may not have noticed that!

 

Has anyone replaced the rear springs with the Arnott rebuilt units. I have the top installed but cannot get the spring to compress into the mount.

I have removed the pressure stopper in the air line attachment but the spring will not compress as easily as the one that I have just removed (that might be because the one I have removed is broken....

Any advice. Should I be able to compress it by hand, slowly, as I can with the removed unit?

 

OK, just finished replacing the rear left spring. A couple of other recommendations I would add to the procedure for the rear.

1. Before shutting off the car, remove the Park Brake fuse (F32 Trunk). There's no need to disconnect the park brake cable, but if the brake is applied, it restricts the range of motion of the new spring and I had difficulty getting it aligned and seated with the upper mount.

2. Remove the tie bar before removing and replacing the spring.

 

Interesting! I had never heard of the rears failing.

 

Mine are fine on a 04 XJ8. However out of learning something new I followed this and have a question:

At Arnott's site they ask if you have comfort or sport suspension. They want you to run your VIN by the dealer. At www.jaguarparts.com (higher than Arnott) they say that comfort goes up to VIN #....G35210. Is that where the difference is?

Since mine was new, it raises when I get out and then bleds the air down. Usually it doesn't raise when I start it up. I can see it level itself at stops where the ground isn't level.

 

theyre not and I have 2 sport front air springs, and some comforts, used. sport have red identifying dots at the top and comfort green

 

I may have found a solution to the computer ride height problem. I thought I'd followed the directions given in this thread exactly, but for some reason, the side that I didn't replace ended up very high. (I replaced the driver's side.) I could fit all 4 fingers up and down between the tire and the fender on the passenger side. The side I replaced seemed to be normal, as I could only fit about 2 1/2 fingers. (Real technical, I know).

I drove it around like this for a few days hoping it would level itself out, but it never did, it always pumped back up.

So, here is how I fixed it. (Front only)
1) Turn off the car on a level surface
2) Unplug wire on top of both shocks
3) Disconnect the air hose from both shocks and let them completely drain. The car should now be completely lowered in front.
4) Reconnect the air hoses and reconnect the wire.
5) Start the car.

The pump will now pump up both and the ride height should now be what it was before you screwed everything up.

Here's my opinion on how it happened.

There is only one height sensor in the front. It's on the driver's side. There is not one on the passenger's side. Before I lowered the car, I reconnected the battery. I dropped the drivers side first, then dropped the passenger side (I don't have a lift). The pump started pumping between letting down the drivers side and the passenger side, when there was an unequal weight distribution.

During the three days I was driving around thinking I was going to have to take it to a dealer, the computer was maintaining different PSIs on the different shocks to maintain the ride height on the drivers side. It had no idea what the passenger side was doing. Once I drained out all of the air pressure on both sides, it pumped up both at the same rate until the drivers side returned to it's calibrated level, which was now the right level for the passenger side as well.

I'm sure there is an error in my technical description. Most likely in the "different PSI" theory because I really don't know what that computer is thinking, but my fix worked and I thought I should share it to save those of you who don't really want to look like an idiot to your dealer.

Mark

 

Please also send to wwahl@cfl.rr.com

Thanks for the great writeup.