BMW 5 Series (E39) rear shock strut removal

Background
I had a broken spring on my E39 5-series, and the Bentley manual. I rapidly discovered that the documentation of the trim dissassembly needed and techniques wasn’t so much sparse as simply missing.
I therefore set out to write down the steps required, both to ensure I got everything back in the right order, and to help anyone else in the same spot.

Reproduction
The article may be reproduced elsewhere, provided a link back to www.tristanscott.co.uk is given and this notice remains within the article.

Tools Required

  • Good socket set (8mm to 24mm, including 16mm and 18mm) and various extensions and ratchets. Eventually, torque wrench.
  • Flat screwdriver x 1
  • Taped up flat screwdriver (or plastic trim pry tool) x2
  • 8mm allen key
  • posidrive large screwdriver
  • means of gripping and lifting expanding plastic rivets (sidecutters or
  • pincers ideal)
  • plenty of time
  • somewhere large flat and clean to place removed trim panels on
  • a pit (the car is assumed to be parked over a pit with underside access)
  • Two jacks capable of lifting using the jacking points (or bits of wood to pad with)
  • Two axle stands and bits of wood for padding

Relevant options on car

  • No HPS rear airbags (major differences)
  • Rear Sunblind (minor differences)
  • DSP (12 speakers) (extra steps)
  • Split folding rear seats (major seat differences)
  • S-EDC (plug to be removed from shock top)

Procedure from parking over pit, to spring/shock replacement
(work upwards for reassembly, but read notes at the bottom before reassembling)

  1. Park over pit (or otherwise have access to underside of car before lifting).
  2. Disconnect battery (read notes at bottom before starting).
  3. Check you haven’t got Rear Head Protection system (HPS) Airbags. If so, don’t use Bentley manual as they’re not listed. Find out how to disable safely. Thankfully, I don’t have them, so onwards!
  4. Pry lights out of C pillar (two catches at the top, using two screwdrivets walk from front to back along the top should get then, then they fall forward.
  5. Disconnect light wiring harness.
  6. Undo two bolts behind each light to release C pillar trim.
    Pry out pop fastener behind light using screwdriver (protect paint with tape round screwdriver) – don’t pull C pillar trim to release this, the trim’s not that strong!
  7. Pull C pillar trim forward slightly, then lift and work out. 4 tabs along the bottom should pop out easily apart from back one which tends to be a struggle, but doesn’t break.
  8. Lift headrests out (they will lift, but have a final catch you have to overpower. It won’t break.)
  9. Lift seat base out (lift front of seat base, one catch each side will pop up, then just lift out). Remove pile of money, fluff, golf tees, mice etc etc from under seat.
  10. Undo two bolts (one each side) to release bottom of side bolsters of seat back. Pop top off (carefully, takes considerable force) then lift forward and up to release metal tab near bottom.
  11. Working in boot, pull two expanding rivets from boot top trim.
  12. Remove two nuts from same trim, near back of boot top.
  13. Hinge boot trim top trim down, unplug subwoofer wiring harness (nearside of car) and undo third bolt to allow subwoofer to swivel down.
  14. Hold subwoofer up in position, and pull backwards gently. Lift at the front, at the two sides where it hinges to drop out tab “hinges”.
  15. Remove two rear seat back catches (metal loops) using 8mm allen key.
  16. Remove 6 expanding rivets from rear seat back landing spot (sort of anti-rattle strip). Careful – the centers of the plastic rivets come out using side-cutters or careful flat screwdriver, then the outsides of the rivets tend to catapult over your shoulder as you pull the trim away…
  17. Trim slides downwards though where seat catches were.
  18. Undo three nuts from above where the subwoofer was.
  19. Pry speaker grills up from the front. The back catches are easy, the front catches require extreme care not to break (try lifting with one screwdriver and pushing them gently backwards with another).
  20. Remove 17mm bolt seat belt side bolster anchors (below the seat squab) – note the under-seat damping trim may have to be cut to allow access (mine looked like someone had already done this rather badly).
  21. Unplug sunblind harness from car. It’s a purple plug on the offside, wrapped around the loom once, about door catch height.
  22. Pull parcel shelf forward about an inch (use front lip and back of speaker grill apertures as handholds).
  23. Using a screwdriver or suitable metal rod, lift three bolt/studs in top of boot so they clear their slots (they will lift quite easily, and you’ll see the parcel shelf lift). This allows the parcel shelf to move further forward.
  24. Pull parcel shelf forward and drop the front down into where the rear seats were. Roll it over so it’s inverted (the seat belts are still through it at this point).
  25. Pop out the three plastic seat belt apertures, and thread them, the seat belt latch, and the anchor point back through the parcel shelf towards the (still attached) reel.
  26. Remove parcel shelf from car.
  27. Unplug main parcel shelf speakers (a flat screwdriver pushed outwards and down from the top of the plug releases them easily).
  28. Unscrew speaker mouting plate (two large screws near front, posidrive).
    Undo 17mm nuts holding reels in place (correct socket extension on the 17mm socket and care needed on the side reels as bar head will be very close to diversity ariel electronics.
  29. Remove all three seatbelt reels.
  30. Peel back noise damping trim to reveal, finally, the top of the shock mounts.
  31. Unplug shock absorber harness (if S-EDC).
  32. Pop nylon ring off top of shock absorber (inside car) and thread off wire.
  33. S-EDC Only: Turn rubber cone inside out and thread back along wire (where it meets the wire there’s a little collar it needs to be popped off (don’t pull the wire).
  34. Unclip the plastic wire-guide off the top of the strut, and unfold away from wire.
  35. —————- Switch to working under car (and out of clean clothes) at this point —————
  36. Loosen (break free) wheel nuts.
  37. Loosen (break free) shock bottom mount (24mm).
  38. Loosen (break free) long bolt through wheel end of bottom wishbone.
  39. Loosen (break free) bolt through wishbone inside front mount.
  40. Punch two small holes on the eccentic washer and wishbone near the inside rear mount to mark position of the washer.
  41. Loosen (break free) the bolt through the inside rear mount of the wishbone.
  42. Chock front wheels.
  43. Lift car using the official jacking points (the bottom of the sills, in the plastic socket, just in front of the rear wheels. Note the rear differential is not designed to support the car, and is mounted on small bolts not designed to take 900 kilos.
  44. Support car on rear suspension subframe “big bolts” using axle stands and a hardish piece of wood to protect the bolt.
  45. Remove wheels.
  46. Undo three 13mm nuts from the top of shock, leaving one nut loosely on to stop the shock tower falling out.
  47. Support wishbone assembly to prevent it dropping further than the shock maximum drop.
  48. Undo shock bottom mount bolt and remove.
  49. Undo rear anti-roll bar bolts (10mm internal holding spanner, and 16mm socket).
  50. Undo roll sensor arm from subframe (10mm spanner each side) and release from lower wishbone.
  51. Undo wishbone outer long bolt (24mm nut, 18mm bolt) and withdraw.
  52. Undo wishbone inner forward bolt and remove (note captive “nut” you’ll have to catch as it drops out).
  53. Undo wishbone inner rear bolt and remove (ensuring you have recorded the position of the eccentric toe-in adjustment bolt as in step 40).
  54. Drop down and remove lower wishbone.
  55. Clean all bolt “landing” surfaces around where washers were (as they may not land in exactly the same position on reassembly).
  56. Holding the shock absorber (you may need an assistant), undo remaining internal shock top nut, and remove shock strut from car.
  57. Dissassemble strut and replace shock absorber and/or spring as necessary (note shock top nut needs to be threaded carefully over the wire and plug of S-EDC, if fitted.

Upon reassembly, lubricate all bolts, nuts, etc as normal. Torque all nuts to torques as given in Bentley Manual (or to a suitable tightness where torques not given). Bolts through the three bushes of the wishbone must only be torques up tight when the car is resting on it’s wheels again and has been rolled forwards and back a few feet (so the suspension and tyres are relaxed to their normal positions). Also note that the car (if auto gearbox) cannot be taken out of park with the battery disconnected, so it might be better to put into neutral (thereby locking key into ignition) before disconnecting battery.

Note: When re-assembling the shock strut, ensure a side of the triangle formed by the top bolts is parallel to a line formed by the bolt-hole at the bottom before releasing spring compressors (otherwise it won’t fit and won’t turn when reassembled into car)

Note: When re-attaching rubber cone and nylon ring at the top of the shock inside the car, fit the plastic wire-guide curver first, then the rubber cone (turn the right way out before sliding down wire). Then fit the nylon ring down over the in-place rubber cone until it “pops” into place.

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