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How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 3:19 pm
by Jembo
I've fitted quite a few rear shock absorbers in the past so thought walk in the park - think again as the top mount is hidden under the plastic trim that's connected to the rear parcel shelf that's connected to the sensor that decides whether you're allowed to have wind in your hair.

My choice, a pair of Bilstein rear uprated B6 shockers - early impressions are why did I leave it so long, as the composure of the rear is vastly improved, doesn't sag anywhere near as much as before so again makes for a more planted feel as the dreaded flex in the suspension's kept more under control.

This by far was the most information I found on the topic http://www.bimmerfest.com/forums/showth ... p?t=247840
though in practise it tells you the steps, though not how to execute it & also found some things mentioned weren't necessary (like remove the knobs off the shelf & dampers which for the life of me found impossible)

So, here we go...

1. Read the link above. It's got a good diagram and it's possible with a bit of imagination to get the job done

2. If it's your first time, plan for at least 3 hours - you need patience to remove all the plastic clips without damaging them so start in the morning on a sunny day

3. The roof needs to be up, find your tool set to get out a flat head screwdriver; pair of pliers, 10/11mm for hexagonal nuts; 17mm socket (wheel nuts); 18mm socket for lower shock mount & a set of open ended spanners from 6mm - 14mm, trolley jack, stop blocks for front tyres & a couple of pieces of wood to make taking tyre off/on much easier

4. Pull the boot bulb holder away from the trim & disconnect it at the cable

5. With the shelf in the lowered (roof opening position) Start by levering off the plastic edge of the fabric trim that connects to the metal shelf all he way along the shelf. By placing the flat screwdriver underneath the plastic edge, you can lever it off at on end & gently feed the rest off

6. Raise the shelf by turning the knobs into the upper position & then remove the two hexagonal bolts (note I did nt have to remove the knobs or damper mech as per other instructions)

7. Where the shelf joins the knob lifting mechanism, there are 3 small plastic clips each side that need to be removed. You can either use the flat headed screwdriver & push them up from inside the boot, or, reach over the seats & try to pull them out (I found easier to push from underneath & risked loosing them)
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8. With light inward pressure on the folding metal flanges that support the roof, the plastic clips should release the shelf which can then be removed by carefully lifting it upwards, inwards & to the right, while SLOWLY rotating the left side downwards. Ths should allow you to remove the shelf in its entirety... even allowing you to feel your drains on bth sides.

9. You'll find a small plastic pin & pressure clip. Simply use the pliers to pull the pin out & the plastic lug can be levered out with the flat head screwdriver
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10. Deep breath... the plastic cowling attached to the metal flange lifting knobs should now be loose. By FIRMLY pulling backwards & slightly inwards, you will be able to remove them (note I did not have two plastic pins & lugs each side as suggested by the other instructions). Ths is a little tricky so take your time, as u don't want to damage anything but won't come out willingly.
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11. Under some foam, the Holy Grail of... the top mounts are exposed. iwas supplied with a new bolt, but had to re-use my old rubber mounts, upper shock cage & bump stops.
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12. Crack the torque of the wheel nuts, locking wheel nut always first, blocks under front tyres & then jack up & remove the wheel - tip, placing a piece of wood either side of the wheel will help both with removal & refitting... and often stops accidental smashing of the rim against your discs!!!
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13. Place a block / axle stand underneath the main knuckle joint so the shock absorber has no suspension tension

14. Remove the top shock absorber nut by simply using one spanner to stop the shaft rotating, the other to undo the nut anticlockwise

15. Remove bottom shock bolt with 18mm socket
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16. Re-use (as in my case) old bump stops & upper casing & refit lower shock bolt first, upper one second & torque up

17. Refitting is pretty similar to taking apart - sometimes the foam gets in the way on the top mount so you may have to partially remove it

18. I also found refitting the clips was a little tricky & best done with shelf in lowered position - the nearest shelf clip to rear fitted within the boot, the clip nearest the seat from inside the car.

19. Make sure the shelf sits nicely in the groove for trouble free roof operation
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Hope this helps someone, even if it is just to clean the rear shelf & fondle the drains

Re: How to - E85 rear shock absorber fitting

Posted: Sat May 04, 2013 4:24 pm
by -Tom-
Great write up. Patience is a virtue with this job, makes you wonder what pleb designed all these tacky bits of trim in the first place. Indy garages must cringe when they see a z4 roll in booked for spring changes :D

Sent from my Galaxy Nexus using Tapatalk 2

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 7:05 pm
by andysat
Good write up -another crap design :roll:

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 10:12 pm
by Jembo
andysat wrote:Good write up -another crap design :roll:
... Not if you're a BMW dealership :D

Mods, did I notice a number of How to guides sitting in the general bucket, rather than the group headings. Cheers

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 10:14 pm
by McKoval
I also helpp this will help me as I will be fitting my KW v2's next week :)

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 10:17 pm
by Jembo
McKoval wrote:I also helpp this will help me as I will be fitting my KW v2's next week :)
Provided you take your time, u will be just fine. Just PM if u need more info

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 11:30 pm
by Bing
Nice write up Jem :thumbsup:

Assume the bolt torque settings are in the other thread linked ? Sorry, not read it :oops:

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Sat May 04, 2013 11:32 pm
by McKoval
Jembo, Thanks - will probably be doing this in my friends shop - he's an independent mechanic and a rallyist so probably everything is going to be OK :)
We are only afraid of removing those tray mounts - rest is pure mechanics :thumbsup:

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Thu May 16, 2013 10:12 pm
by McKoval
I finally have my coilovers fitted :)
We actually even found a solution to readjust them without removing anything from a car:

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Essentially we drilled holes in the top of the plastic "domes" in elements 3 and 14
Now there's quite a lot of place, even to put an adjuster extender, but I don't know if the extender wouldnt harm the softtop glass so we decidded to leave it alone - KW's are adjusted with 2mm allen key, so no problem using it that way.
If one isn't flexible enough, then another easy entry to this holes is after opening the sofftop tray cover (number 2 on the picture above).
However - first of all we drilled small elegant holes, but after few minutes we knew it wouldn't be enough as the top af the shock may move around a little in the top mount, so we made huge and ugly holes, but they cannot be seen with the roof down, and are quite well hidden to spot with the roof up.
Unfortunatelly I was to much into drilling and fitting and so on that I haven't taken any pictures :thumbsdown:
Will try to do some in the nearest future.

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Thu May 16, 2013 10:23 pm
by Jembo
McKoval wrote:I finally have my coilovers fitted :)
We actually even found a solution to readjust them without removing anything from a car:

Image

Essentially we drilled holes in the top of the plastic "domes" in elements 3 and 14
Now there's quite a lot of place, even to put an adjuster extender, but I don't know if the extender wouldnt harm the softtop glass so we decidded to leave it alone - KW's are adjusted with 2mm allen key, so no problem using it that way.
If one isn't flexible enough, then another easy entry to this holes is after opening the sofftop tray cover (number 2 on the picture above).
However - first of all we drilled small elegant holes, but after few minutes we knew it wouldn't be enough as the top af the shock may move around a little in the top mount, so we made huge and ugly holes, but they cannot be seen with the roof down, and are quite well hidden to spot with the roof up.
Unfortunatelly I was to much into drilling and fitting and so on that I haven't taken any pictures :thumbsdown:
Will try to do some in the nearest future.

Did you do your drains while you were there from the top with a piece of wire?

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Thu May 16, 2013 11:31 pm
by RJS-Z4
Jembo, you are my god. I've been looking for one of these...

Now comes the question, to uprate or not.

Were you not tempted to uprate the top mount whilst you were there? Apparently they're a weak point?

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Thu May 16, 2013 11:47 pm
by Jembo
RJS-Z4 wrote:Jembo, you are my god. I've been looking for one of these...

Now comes the question, to uprate or not.

Were you not tempted to uprate the top mount whilst you were there? Apparently they're a weak point?


Mine seemed OK, though I was more concerned about breaking the shelf mech ... though once you have done it once, is relatively straight forward

Re: How to - E85 Z4 rear shock absorber fitting

Posted: Mon Sep 14, 2015 8:56 am
by Mpathic
A bit later than the last comments, thx to the British who took pictures instead of my fellow 'mericans who babbled obtuse words with partly unnecessary and conceptually impossible instructions. you turned a :headbang: of a job into :thumbsup:

Note about rear shock selection:
With the pita job that it takes to get at the Z4 upper strut mounts, its not a practical option to make quick adjustments at the top of the shock. The Koni DA listed for Ford Mustang that work great on other BMW models are left being SA with a click screw for bump at the bottom, and a pot luck guess where you set the top for rebound.
So save a few hundred dollars or pounds and go for the KYB dual adjustable listed for Ford Mustangs. 2002 is a good target year to look up the application. These are DA, but with one single click knob at the bottom. The knob has 8 positions that adjust both bump and rebound equally.
They're valved for a higher HP much heavier car, so the first or second position is fine for a stock spring street car, maybe click 3 or 4 for an aggressively driven M car. Use with the rubber bushings that come with the shocks, inserted into a nice aftermarket shock mount like Ireland Engineering makes. Ireland's are nicely well suited for the Z4 because they supply a reinforcing plate that has studs welded in from the top down. This lets you tighten the nuts from inside the wheel well, Much easier than wiggling and squirming hands and easily scraped knuckles in that tight space over the shock tower. You also then never have to disassemble all that overengineered plastic crap just to remove the shock again.

How to - E85 Z4 rear shock absorber fitting

Posted: Fri Apr 08, 2016 9:52 am
by Worcester_spoon
This guide has been hugely helpful, thanks. Got to this stage in about 30 mins :D

Shocks, bushes, mounts and limiters going on tomorrow morning :driving:

How to - E85 Z4 rear shock absorber fitting

Posted: Sun Jun 26, 2016 4:57 am
by igeak691
This guide was super helpful for me in making this video. Hopefully the video further helps people visualize what's going on :thumbsup: