2 Lemforder arms + 750 bushings pressed: $200 US
- Bavauto: 2 arms with performance bushings: $300.
- BMW: 2 arms no bushings: over $400 (always makes me laugh...)
Thrust arm bushings should always be changed in pairs. You
will need a press or find a shop with a press if you are not
changing the whole arm.
The BMW 750il and 850i have a stronger heavier bushing designed
for the greater weight of the BMW 750 and 850 front end and
engine. They give a firmer tighter suspension feel and steering
response. I would not change them until you have problems
with your existing bushing.If you have a fair number of miles
on your car when you do change them you may as well do the
arm and the bushing, since half the time the ball joint is
Note from Dan Pitts
Thanks for the information concerning how to replace thrust
arms. One thing that may be helpful in the procedure is jack
up the wheel to take some load off of the ball joint before
trying to separate the ball joint from the wheel assembly.
I had two pickle forks completely wedged under the ball joint
with no movement. I reluctantly put the wheels back on (but
not the 22mm nut) and backed out of the garage to prepare
for a disgraced drive to the mechanic, when the ball joint
popped out. I then replaced the left thrust arm and resumed
work on the right side after this moment of joy, but this
time I placed the jack under the control arm ball joint and
took the load off of the thrust arm ball joint. This time,
the ball joint came right off using the pickle fork (actually
I used two due to the thickness of the boot). Anyway, thanks
for the procedure and the tip on replacement parts.
Note from Dan Trevor D:
On Friday I replaced the Sway bar link, Thrust arm and Control
arm on my 89 535iA using the sections from your troubleshooting
section on the thrust and control arms as a guide.
One thing that I discovered was that to remove either the
Thrust arm and/or Control arm from the suspension mounting
plate, the following simplifies the procedure:
Once three bolts from suspension mounting plate are removed
Remove bolts from Control arm and Thrust arm Bushes.
Remove nuts from ball joints of Control arm and Thrust arm.
Remove sway bar link (17mm) from mounting plate.
Remove tie-rod from mounting plate with a tie-rod puller (I
bought one from Repco for $30, probably cheaper in the US)
Mounting plate with Control arm and Thrust arm can now be
On your workbench you can now gently knock/tap out the ball
joint/s from the mounting plate with a pound hammer.
I had initially struggled to try and remove the ball joint
ends of the Control arm and Thrust arm from the mounting plate
while still attached to the underside of the car.
Using the above procedure I estimate the total time to replace
Control arm, Thrust arm and sway bar links to be 1-1.5 hours
P.S. I used a trolley jack and 4 x axel stands 1 under
each front jacking point and two under the cross member under
Note from Rustam:
My tip is the following: The person should use a blade to
remove original ball joint boot such that no rubber of it
comes in contact with the fork that is used. The reason for
this is the following. If the rubber remains at any rate,
the pickle fork being driven with hard blows of the hammer
gets tu push right against the rubber which dissipates the
shock thereby cushioning the fork, precluding from break up.
If the rubber does not exist, the fork is driven directly
gainst the metal and the shock transfers wholly, imparting
maximum energy to metal. It takes no more than 5-10 energetic
blows for separation.
Consequently it is better to remove whole assembly along with
both arms and steering arm to preclude the shock transferring
to bushings as is already suggested by someone else.