I'm sure there's a post about it as I can't be the first, but the google search gremlins are preventing me from finding it.

06' XJ8L, 69K miles. Upper control arms need replacing and wondered if anyone has the protocols on hand for removing and reinstalling OG air strutts. Can't find anything online about how to go about recharging the system via external equipment or if the onboard compressor can handle it. It's the final piece in my front end clunk crusade.

 

You replace the upper control arms with the shock absorbers removed. This isn't easy or pleasant, as access to the bolts from the engine side is difficult.

I have a PDF version of the Bilstein manual somewhere; I'll look for it and send it to you.

 

Here's the Bilstein instructions that come with new air struts. The are both in German and English.

Best regards,

Thomas

 

Thanks Peter and Thomas! I'm not looking forward to this but need to get rid of the clanking.

 

Have you replaced the sway bar bushes and sway bar end links? That was my source of clunk. But I also replaced upper control arms. I recall accessing the bolt head/nut for one side was very tricky from inside the engine bay and under the plastic cover by the brake fluid rez. Mine is 2008 but probably similar. I will look for pix I might have taken

 

Only one pic but some nice parts diagrams of front susp. I think the only reason the bloody air strut has to be moved is because the bolts on the upper arm will not slide out otherwise.

As you can see from pic, the nut on the bolt is inside the engine bay. Just need to locate them and have long arms to hold underside bolt head while turning nut. Don't drop the nut either into nether land. Maybe a helper is good but I managed alone.

Also you may know but just snug up two bushing bolts, then need to get suspension at proper ride level before torquing to final tightness. But you'll never get a torque wrench near those bolts so just crank on them best you can.

 

Also I do not recall any procedure for air suspension to restore itself. I just recall being SUPER careful disconnecting the electrical and air pipe off the top of strut. Those plastic pipes are brittle as hell

 

"Front upper control arm - advice needed"

Search for the above post title. Some good info sbout accessing nuts.

 

Thanks Worzella. New tie rod ends, sway bar links. Everything else has decent bushing life, except for the upper A arm. Appreciate the diagrams and heads up about dropping those pesky nuts into the ether.

 

Not sure what you mean by decent bush life, but if those two front sway bar bushings are original, they are long dead. Even if they look tight and you can't manually cause a clunk by wiggling them, they should be on the suspect list.

But fix the A arms indeed and if clunk still there, try this. Disconnect sway bar end links and wire sway bar just to keep it roughly in place. Then in a safe place where you know you here the clunk, drive over it. You might be surprised it is gone. This is pretty foolproof means of determining if front sway bushes are the culprit.

Goid luck!!

 

I just looked back and see 69k miles. So agreed that rubber bits have not had much road abuse, but 19 yr old rubber goes bad on its own sometimes

 

Yes another vote for sway bar end links and sway bar bushings.
This is easy to test too.
Remove one end of the sway bar end link on both sides. Now go drive the car where you know you will get noise.
This will quickly tell you if those parts are the problem.

But listen to worzella as these parts are super common to wear out. And as he posted they are now 19+ years old and well past their service life.
.
.
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And Hames -

Please continue this coversation after you try whatever you try. Nice to know the final solution once you get to that happy point.

Best of luck

 

Hi all,

Quick update for you all....

Control arms replaced. The louder "THUNK" has gone away but there still is a rattle, or shuttering when going over sharp bumps in the road. Something I can live with until this no longer is my daily driver. I suspect this is in fact the sway bar bushing, and will try and get under the car before heading on vacay in two weeks.

Mechanics (I took the big cat in this time as I didn't have the time or space to do it myself) noted that the car took longer than in noted in the manual to reach ride height, and now I have the "Air Suspension Fault" warning on the dash. The compressor seems to kick on more that it used to. Can't get a straight answer from a forum thread, but am I correct to assume that the fault will eventually clear once the car finds the height? All 4 corners inflates on starting the car and the shop didn't find any air leaks, or any evidence of air leaking. Any info on this?

Jimmy

 

Not sure but there are ride height sensors all in that front suspension area. Any change they got bumped or jostled while working?

 

Something I can ask the shop. They didn't specify anything of that sort (why I like to work on my own vehicles).

 

I was waiting for you to write: I have new upper control arms, but the rattle remains, hehe. Anyway, if you replace anything that requires disconnecting the height sensors, you'll need to calibrate the suspension afterwards. Your car doesn't know how high it is. And even if not, if you keep it on a lift in strange positions, e.g. on one wheel, or park it in such a way that the wheels are constantly at different heights, you still need to calibrate it from time to time because the suspension module simply goes crazy.

 

Thanks for the tip Peter. Is there a way to do it yourself or is this a exhausting trip to the dealer?

Have you gone down the sway bar, tie rods, front lower control arms rabbit hole?

 

A dealer is an option, not necessary for now, but you'll need an SSD and a cable. The cheapest option is a Mongoose clone from China. You choose the SDD for your Windows laptop or tablet's operating system. Calibration is a simple procedure, requiring no battery backup. You can learn how to use the SDD yourself, as far as you feel you need it, or you can learn from someone directly or even remotely. Of course, you can't be too pushy, as you might break something. The key is a charged battery and a powerful power supply, with 30 amps a minimum.

As for the rattling, there are a few options, but I'm in a different time zone, so maybe we'll come back to that later.
I've gone through everything including complete disassembly of the suspension, front frame, stabilizer bar, shock absorbers, etc.

 

Regarding the rattling, with my car it was the sway bar bushings in the end. I had already replaced everything else, and the rattling was still there until I finally replaced those bushings...

Best regards,

Thomas