yzhou2004 wrote

I searched left rear suspension yesterday. Unfortunately A-premium web site only offers front.

The other options I have:

1) $300-400 aftermarket on ebay (made in china some shipped from US warehouse. Feel may be same source from A premium)

2) $500 OEM rebuilt from a company Rebuildmastertech.com based in FL. with $150 core deposit. Their website looks very professional

3) $900 from aerosus based in Germany. They replied my email said they have manufacture around the world complying with same high standards. Price includes shipping and tariffs with 2 year warranty.

4) $1500 from online BMW dealer.

I am opt for either 2) or 3)

What do you think given your experience.

I have more questions regarding installation later. Thanks.

Bumbleboy92 wrote

I'm cheap, so I would be leaning towards 2)

yzhou2004 wrote

Yeah, I am leaning towards to 2) now too. Contacting them regarding warranty policy, though i don't mind risking $400 w/o warranty.

This afternoon I opened my hatch and try to replicate procedure from interior. To my surprise, I can skip most of steps. Those may be applicable to your 3 row version.

What I need to do are only 1) lift trunk floor trim panel 2) remove a plastic cover 3) remove a foam insert. Then four top mounting bolts reveal. I should have plenty room to remove and reinstall from the top.

Hope I am not overly optimistic here.

Bumbleboy92 wrote

Oh yeah that’s much simpler, the third-row sits practically on top where the struts mount

yzhou2004 wrote

Now I am researching how to swapping out air struts. Could not find YouTube videos on G05.

A few questions in my mind

1) did you use a lift or floor jack/stands to lift the car? I don’t have a lift but only 3 ton floor jack, a pair of 3 ton jack stands and a pair of car ramps. The max cleanable I can get from my set up is around 17 inch. Wonder if it will give me enough room to work underneath. I remember using the rear center jacking area (was it the rear differential?) and having the two jack stands at the two rear jacking points along the side of the car

2) was it easy take off 4 bolts and nuts from camber (lower) control arms before removing air strut once the car is up in the air? Any sequence matters? Preload or not matters? Any thing got in your way? Did you mark eccentric bolt position before removing it?

Bumbleboy92 wrote

2) Taking off the bolts is easy, have a breaker bar on hand. I had a 1/2” breaker bar and a set of 1/2” impact sockets that I used with it. At the time I didn’t mark the bolts but I remember the lower control arm bolt (closest to the diff) is to be installed in a specific orientation according to ISTA. Everything else is regular unscrew then tighten and tighten again with preload.

One little side note, one of the forward sway arms is bolted in such a manner that I could not get it out, after checking ISTA it turns out to remove that bolt you have to lower the entire rear end. So you’ll have one arm that can’t be removed but shouldn’t affect being able to remove & install the strut.

yzhou2004 wrote

For tighten with preload, did you measure the distance between center of wheel hub to the edge of wheel arch fender and lift the suspension with a second jack on wheel hub or control arms? or you lower the vehicle on a ramp or something. I have seen people did both on youtube videos when changing tension struts.

Also, on the side note. do you mean you only remove three bolts (one eccentric to subframe and the closest to differentials, one to wheel carrier and, of course one to air strut joint bush) and leave one connecting to one forward sway arm loose without being removed?

From attached ISTA (left rear forward view), there are four bolts to remove to take off camber control arm.
I can tell the outermost bolt is connected to wheel carrier, the second to the outter is the bolt mounted through air strut joint bush. The innermost one should be the eccetric one to subframe which should be positioned in a specific way. From the diagram I am not the clear what's the 3rd bolt connected to. Maybe that's the one to forward swing arm you are referring?

Are you saying you don't have to take 3rd one out (red circled) to remove and reinstall air strut?
weird I did not see the requirement of lowing rear to remove 3rd bolt. Maybe I am misunderstanding something.

Bumbleboy92 wrote

For the preload, I pretty much just let the car sit on the ground and then tightened everything as much as I could. I didn't take the technical route back then.

Bumbleboy92 wrote

The eccentric bolt will probably give you the most trouble on install with trying to align it if I remember correct.

yzhou2004 wrote

The max clearance with highest air suspension is about 10 1/2 inch.
Very impressive you can get under to tighten the bolts.

1) Did you use extension bars to do so? Or you got under the car and manuver torque wrench in the limited spaces?

yzhou2004 wrote

2) Did you always need to use either socket or wrench to hold one side and then torque wrench to tight the othr side? I guess if not always holding the opposite, the bolt or the nut will keep spinning.

yzhou2004 wrote

But I have a question why a special tool is needed "to make joint bushing tension free" as ISTA required. I could not figure out where the tension comes from during the installation steps. Still need to think a bit more how I should loose the tension w/o the special tool. Maybe a bottle jack with an arc adapter to push from below?

yzhou2004 wrote

#4 Eccentric bolt(front)/washer(don't know where it is yet )/nut(rear) set:

yzhou2004 wrote

A cross bar is somewhat in the way of tighten and loose the front 18mm hex bolt. It is a similiar similar situation as in #1 knuckle nut. I am planning to use a pass through socket to hold it while tighten the rear 12mm nut with torque wrench.

yzhou2004 wrote

3) when you replace air struts, did you reuse all bolt/nuts/washer or you renewed them?

yzhou2004 wrote

4) one more thing:
do you remember how to uplug the connector to air strut (last picutre)? I am always super panoroid about the connectors and afraid of breaking them off.

Bumbleboy92 wrote

That connector is easy, a simple tab on the wire side you push while pulling the connector back, and it will unclip. I had to replace my RR strut due to that connector being damaged on the strut itself, as you can see in the above image.

Bumbleboy92 wrote

If you can get another person to help it’ll cut a lot of the time needed as I only disconnected one side of the lower control arm. Had my brother leverage the strut up and out from the front drive axle. Hardest part was doing the same on the new strut, I could easily compress the old strut but the new one was incredibly more stiff hence needing two people.

Did you have to compress it somehow at installation? Since the new strut should have no air it, did you have to compress shock absorber? I hope not

yzhou2004 wrote

Did you have to compress it somehow at installation? Since the new strut should have no air it, did you have to compress shock absorber? I hope not I know this post was referring to front, but I have questions on installing new strut on rear camber arm as well.

yzhou2004 wrote

3) remove four sets of bolts/nuts on camber arm in the order from inner (eccentric) to outer (knucle). Did you have hard time to remove any these bolts/nuts given the suspension is dropped somewhat while car is on jack stands. Could removing one bolt/nut cause more tensions on the rest so that it is harder to remove?

yzhou2004 wrote

At this point, I assume old air strut after being fully bled will 'shrink' from pre-deactivation height before being jacked up to stands? Say, if I leave air suspension at highest level before deactivation and jacking up, the strut will shrink the most after being removed?

yzhou2004 wrote

did you remember how hard to align bolts with holes on camber arm? did you have to use a second jack to fiddle suspension height somewhat along the way to make bolts and holes lined up one after another, for the strut, sway bar end link and rear axle assembly in sequence

yzhou2004 wrote

My main concerns are

1) if knuckle bolt/nut is tightened to spec 165nm first, will it be hard to rotate/fiddle camber arm to align the other bolts and holes?

yzhou2004 wrote

2) The bolt/nut to air strut joint bush was removed before the old strut was full decompressed. When new strut was put back in and it should be fully decompressed and may be somewhat 'shorter' than the old one before being bled and unbolted? Did you need to fiddle camber arm for proper alignment.

yzhou2004 wrote

Once the new air strut is in place and the car is lowed on the wheels. Before turning on engine and activating air suspension to fill the new air spring the new air strut has no air in it yet. Did you have to do something special to prevent air strut from being damaged? or it should be fine just sit on wheel without air for a short moment?

yzhou2004 wrote

I came across a YT video shows the replacement of front air suspension on G11. The guy had to use ISTA to clear up some codes after the installation to make air suspension adjustable again. Did you remember having to do so?

Bumbleboy92 wrote

I've done the ride-height level relearn a few times, and it was pretty easy, best to use a flimsy tape measure with cm markings as you need the mm readings in ISTA.

yzhou2004 wrote

As helpful as always

I will consult you more about relearn process if I have to.

Unfortunately the rebuilt part came in with a bit beaten up dust cover. Very disappointed. See pic. Emailed the company to ask for an exchange or a return. It is apparently not up to what they described and showed on their website.

To your opinion how important of dust cover? Did all your used or aftermarket parts come with decent shapes?

Now I may have go back to source a part again. There is one OEM made in 2018on eBay claimed to be unused but missing pressure retention valve. It is for sale for less than $300 because the missing part. I found an aftermarket valve online or I can reuse my OEM one. I also came across YouTube videos how to remove and reinstalled the valve piece. Maybe worth of a try.

What do you think if you were in this situation?

Bumbleboy92 wrote

I’d see what the company says about a replacement, in theory it should work but would feel better with a replacement. I’ll take some photos later today of all my replacement struts to see how they look.


I also did see that same struts on eBay but the missing valve housing is questionable, never seen any of these struts not have it already and it doesn’t have a separate part number. It’s all supposed to be one-piece, with that being an OEM part it definitely has something in its history. I’d avoid it but that’s my dislike of used OEM parts speaking.

yzhou2004 wrote

all fair points.

Unfortunately, customer service come back to demand 20% restocking fee plus shipping lable for return. or shipping cost of "courtesy" replacement of boot. or sending me a new boot to replace myself. To be honest, I could not figure how to replace dust boot without taking off the bottom piece.

Not happy with the way they conduct business and dismissive tones. Told them to issue a full refund or a paypal claim and credit card charge back on their way. What a shame.
I would suggest anyone else coming across this post for future suspension work avoid this "rebuild master tech' company. I should have done more review search before I placed the order. Fooled by their web pages.

Sigh, was very excited to do an DIY this weekend. What a waste of time.

Sedoy wrote

Any updates? I'm wondering what did you ended up using for struts?

yzhou2004 wrote

I am living with occasional noise for now. Thought I will take another look a while later once it is cussing me real pain. But I do find more used parts on eBay lately when more cars are totaled over the time.

Bumbleboy92 wrote

I've returned, the first real cold day for us, and drove the car. Heard a suspiciously familiar squeaking...

Coming from the rear.

I'm taking a page out of yzhou2004's book and going to let it be. Only heard it while in the drive-thru at night. I don't drive it often, so until it starts physically failing, I won't touch that again.

I see on eBay that both rear air struts can currently be bought for $220 each, new aftermarket. However, since I have a 3rd-row, it was a pain to tear apart the rear seat area to reach those top bolts.