This message is marked as Important.

Subject: Traction (thrust) Strut replacement on 540i (long)... Author: ripp222 : member since January, 2006 : 189 posts Posted on: 2008-03-02 07:58:04

I recently replaced both Traction Struts (aka Thrust struts, though some people call them Control Arms incorrectly) on my E39 540i. This job


is different compared to the 6 cylinder engine vehicles. I was surprised how lacking the BMW TIS instructions were and wanted to share my


observations...





There is quite a bit of interference in removing the long bolt from the rear of the traction strut where it mounts to the car body.

-By removing the plastic plug and 2 screws from the plastic body trim you gain space for your ratchet to get on the nut

-You have to find space in the suspension area to put a wrench on the head of the long bolt to keep it from turning

-By varying the position of the stabilizer bar you gain clearance for the bolt head to pass (use a jack to move the spindle assembly up/down)

-By turning the steering all the way in one direction allows you to pull the bolt out enough for the traction strut to be free

-Then by varying the height of the spindle / rotor assembly allows you to hammer the traction strut bushing end from the car body

-Disconnecting the stabilizer bar connecting rod gives better range of motion for the spindle / rotor assembly



After you have this all done, then you get to fight with the ball joint end...



I looked at buying the BMW special tool (31 2 240), but the best price I could find was around $210. Instead I bought the "Ball Joint Tie


Rod End Separator - Model 1336" from Kinetik (E-Bay) for $30 + shipping. The negative here is that you have to loosen the pinch bolt and


slide the spindle assembly down from the shock (strut) in order to gain clearance for the ball joint tool.

The tool would not fit around the existing lock-nut, so I removed the nut before pressing the tapered shaft out. The left side went very


easy. The right side sounded like a gun shot once it finally let loose... hence the yellow rope on the tool to keep it from flying!



For installation I used a new lock-nut, but upon tightening... the tapered stud would just spin. There is a 6 mm hex opening inside the


threaded shaft, but the limited clearance didn't allow me to put a hex key in there. No matter as I found you just jack up the spindle


assembly with jack pad on the traction strut ball joint. This kept the threaded shaft from spinning and allowed me to tighten down the nut


to 80 Nm.



Installing the bushing end required several iterations of changing the steering from left to right or right to left in order to get the


bushing in place (a rubber mallet is good here) and then the long bolt through.



After the car is all back together you are supposed to put 150 lbs in the Driver and Passenger seat, then 150 lbs in the back seat, then


have a full fuel tank, car on level ground, THEN tighten down the nut on the Traction Strut bushing.

I just found a sloping driveway, put the car ramps on the lower end and drove up... this gave a relatively level car. Then my wife sat in


the Drivers seat while I tightened the left side, and conversely for the right side.



Conclusions:

- the 50 to 55 mph shimmy that I could feel through the steering wheel is gone

- the car doesn't wander as much during turns

- the old bushings looked just fine for being original, but there must be wear I can't see

- 2.5 hrs for the first side, 1.5 hrs for the second (you should be able to do it quicker after reading the above)

- Get new locknuts per TIS, they're cheep

- 2 jacks are key, one for the car, one to move the spindle / rotor assembly up & down



I stuck w/ BMW OEM parts as my local dealer was willing to press the bushings in at no charge, otherwise I would have used a board sponsor.

Hope this helps!

• Traction (thrust) Strut replacement on 540i (long)... (pic) - ripp222 2008-03-02 07:58:04 (1008 views)
  • Re: Traction (thrust) Strut replacement on 540i (long)... - jager911 2008-04-15 22:34:55 (101 views)
    • The reason he mentioned pressing bushings into new arms - 750il540it 2008-04-16 10:29:37 (75 views)
  • Good info. This is going on e38.org (nt) - davidc 2008-03-07 23:24:58 (100 views)