Suspension too low? By popular demand , here is the how to for changing the front suspension air springs that go bad all the time, at least here in Miami. I included pics, and step by step on every single thing you have to do and watch out for. Please FAQ.

jaghelp.com: How to change the front air springs (suspension struts) on your Jaguar XJ

Like I always said, any questions please comment and I will add the answer. Happy wrenching.

 

Hi, good write up - but FYI:

The adapter that is beneath the air line nut is NOT supposed to be removed (actually, I have read somewhere it renders the air strut unusable and voids the warranty)

Also, I advise against the novice DIYer bending or manually adjusting the right height sensor - the ride height is supposed to be calibrated via dealer level software upon changing a strut.

Finally, when installing a new line nut and olive you need to trim 3 - 5mm of the air line with a guillotine style tubing cutter to ensure the olive grabs the air line.

Hope this information helps - especially the part about not removing the adapter below the line nut.

PS - Don - as I suspected that adapter under the air nut does have an o-ring on the bottom. (Look at the pic on the previous post)

 

Hi Daxter,

Thanks for taking the time to photograph and write up this tutorial! I especially appreciate your humility!

Reading through, it looks pretty straightforward, but a few questions came to mind:

1. Would it be prudent to leave a couple of the air spring/damper nuts threaded on the top studs while disconnecting the suspension components below to reduce the possibility (however remote) of the air spring/damper unit falling on you once the big lower Torx bolt is removed and you're pressing down on the suspension?

2. I didn't fully understand your instructions about the brass air hose fitting and compression ring or "olive." You say to "Pull them with pliers and put first the nut and then the ring." In my experience, olives can be easily scarred by pliers, leading to air leaks. How do you mean for the pliers to be used? Do you need to disturb the olive if you're just going to reinstall the hose on the new air spring/damper?

3. The link you give for the Arnott air spring/damper leads to an Amazon listing with only 3 units left in stock. It might also be helpful to include a link directly to the Arnott Industries page that shows their Jaguar components. Here's one possibility:

https://www.arnottindustries.com/par...FZJm7AodeiwAfA


4. Your suggestion about bending the ride height sensor bracket is something that has been discussed on this forum with mixed opinions. Would you suggest bending the bracket in the opposite direction if an owner wanted to lower the front ride height?

5. If you are replacing the left front air spring/damper unit, do you need to take any precautions to ensure that the ride height sensor calibration isn't lost?

6. You show a computer screen shot of the program you use to read Jaguar DTCs and it doesn't look like the JLR SDD program I'm familiar with. For the benefit of other members, would you mind letting us know what program it is and how well it works on Jags? Since you're suggesting the bracket-bending technique, I'm assuming your program does not have the capability of adjusting the air suspension front and rear ride heights via the Air Suspension Control Module?

7. You don't mention it, but in one photo the boot of the ball joint in the upper wishbone arm appears to be damaged - just wanted to be sure you were aware of it.


Thanks again for taking the time to prepare this tutorial!

Cheers,

Don

 

First of all thank you for such an organized way of asking questions, makes them easy to answer. So here it goes:

1. The tower can't fall because the lower control arms and he sway bar hold it, look how the front control arm is set up, even if the bolts were loose it can't fall.

2. Ok this is the somewhat confusing part to explain to, that brass fitting is an adapter for the hose and a check valve. But, in my experience, it comes off super easy, like they barely tighten it at Arnott. So when you put your 12 mm wrench and try and remove the nut, the whole thing is most likely to come out. when the whole thing comes out I catch it on the Vice and then remove the nut with the 12 mm wrench. Now the post before your mentions that removing this fitting voids the warranty. I can't say it does or it doesn't because I never had to warranty one (that's why I recommend Arnott to begin with) but our supplier will warranty it, yet you need to be a shop to buy from them.

3. Don't worry they replenish quick. trust me, but I like your link and I will add it.

4. Ok let's get something straight, and this is an answer for both you, and the post above you, The Jaguar scan tool (which we have) doesn't have an adjustment fot the ride height. It has a calibration. And for that calibration you need a special tool which measures the distance from the center of the wheel to the arc of the fender. When you have that distance measured by this special tool you are to input it and that is the calibration. I have done this to cars that have sagged over the years but it doesn't bring them to factory ride height. But bending the sensor down (just a bit I'm talking 1 - 2 mm) does. Now, IN MY OPINION, and I said MY OPINION so calm down whoever reads this! ... In my opinion this gradual loss of height is caused by the bracket and the arm slightly bending over time. If 1 mm can change about half an inch to an inch in height then it makes sense. But I have no proof so hey, this is open for discussions if anybody else has another theory please express it respectfully, I'm curious.

5. Again, I tried calibrating cars but it makes no difference. I just replace the struts and bend the sensor slightly (there is an art to this) and it works. Save the customer money and everybody is happy.

6. I'm using Autologic. It can do about 95% of what the Factory Jaguar can do but at 10 times the speed. But my program can calibrate the ride height just so we are clear, but there is no such thing as height adjustment on the scan tool. You can "lie" to the sensors but that might flag codes if you go over the limits, and can't change it much. And the sensor bending technique I was taught by a dealer guy, just saying.

7. I saw the ball joint but the boots on these suspension components is crap, not that the ball joint was making noise or anything. If I start telling the customer an estimate on every single little part that has a torn boot every estimate that I make will come out to be 5000 plus, and they'll look at me like some sort of thieve. I show them but until it makes a noise I don't usually sell it. Is part of being a mechanic.

I wish everybody would ask questions like you do!

 

Way to go Daxter! I fumbled through this job on my 05 XJR and 07 XK a few years back. It was a PITA.
Sure wish I had your instructions then. You have done God's work.

 

Thanks for your reply, Daxter.

Regarding calibrating the ride height, I have had success on two different X350s using SDD, though I did have to lie to the system in order to get the two front corners at the same height on my own XJR (thanks to Cambo for the tip about lying!). I just used a tape measure and carefully eyeballed from the center of the wheel to the lower edge of the wheel arch and it worked fine, no special Jaguar tool needed.

I'm very happy to know that Autologic is so capable and so much faster than SDD. SDD is one of the slowest computer "programs" I've ever used, which I assume is due to its html construction like a big website.

Thanks again for taking the time to put together your tutorial. It will help many owners over the years to come!

Cheers,

Don

 

Daxter, You said to ask questions,so-----


A great picture tutorial. I did notice in the picture on putting the top control arm back, the rubber boot on the ball joint is in the same condition as on mine---wasted. Doesn't that concern you, or, is the fact that it will not cause the damage to the Ball Joint as has been suggested by others?

 

All the rubber boots on these suspension components are crap. If you look at your rear suspension you'll see the same pattern. If the ball joint is loose or making any noise then no I don't sell it. Why? Because imagine if you come for an oil change (which is about 150 bucks already) and I tell you hey you need upper control arms (lets say 600 bucks). You ask why? I don't hear a noise or I don't see a problem, the car drives fine! And I say because the boot is torn. The joint itself is not bad (yet) but the boot is. If it was my car I would've changed the joints for better quality before they went bad, and before the boot torn, but I'm crazy that way, and fixes for me are cheaper since I get parts at a discount and I can do it myself. If everytime you go to my shop and I give you an expensive estimate then I'm no different than the dealer... So yes I do see it, it does concern me, but mechanics have given themselves a bad name over time, and I'm trying to break that.

 

Autologic is the shi* man! There is no other way to say it. It can even program and update modules. Where is this thread about lying to the sensors to change the ride height I would love to read it. Can you give me a link?

 

Here's the link to Cambo351's post and thread on lowering the X350 ride height. The same process can be used to raise the ride height:

https://www.jaguarforums.com/forum/x...e3/#post531488


Cheers,

Don

 

Thanks! Is not something i would sell to my customers but is definitely good to know. It gives me a better understanding on how the system works.