Oilyma

Steering rack and pinion yoke (Thrust bearing) DYI.

Problem.

Wiggling the steering wheel in center position produces a knock even when engine is on. Also, a clunk/knock is felt intermittently in the front subframe and the steering column when going over speed bumps.

Cause.

Out of tolerance play between rack and pinion

Repair.

jack the front of the car
Make sure the steering rack is at dead center
Mark the position of the steering rack yoke cap screw with the yoke housing.
Unscrew the steering rack yoke cap using a long ratchet wrench with hexagon 17mm socket.
Pay attention not to lose the tension spring after unscrewing and Remove gently the o-ring which is embedded in the middle of the yoke housing below the threads.
Use reverse fine spindles pliers to fetch the yoke, by inserting the pliers edges slightly onto the yoke central opening, then press hard to be able to pull it out
Remove the old worn insert foil and clean the yoke with brake cleaner
Lube the surface of the yoke with grease then Mount the new insert foil. Use BMW FB-1 grease which is just a Shell Alvania 0854 grease (heavy duty Lithium based grease). The grease spec is very important as it has additives allowing it to not mix with water or hydraulic fluid
Lube the surface of the yoke housing and apply some grease on the steering rack shaft visible from the yoke housing
Apply some grease on the steering rack shaft visible from the yoke housing after you turn the steering wheel 1/4 a turn to the left
Repeat the last operation but this time 1/2 a turn, then 3/4, then 1 full turn to the right
Repeat the last operation, while turning the steering wheel to the left side
Turn the steering wheel again to bring the steering rack to dead center
Put more grease on the steering rack shaft
Put a good amount of grease on the surface of the insert foil and a tiny amount around the yoke
Insert the yoke back onto its housing and press until it is in contact with the steering rack shaft
Place back the o-ring. Make sure it is well seated (Very important)
grease the tension spring, as well as the surface of the screw cap and the yoke top's surface where they meet with the spring
screw the cap in until the insert foil is in play-free contact with the rack screw. 20nm of torque.
Rotate the steering gear through the total rack stroke (Left/right), 6 times then bring it back to the middle
Turn the adjusting screw 5 graduation marks back (loosen it) and then screw it 1 graduation mark in again.
You can use a dial gauge against one inner tie rod, to measure the yoke play (Specified value is : 0.1mm max)
Adjust the yoke play by turning at the adjusting screw. If the adjusting screw is turned 1 graduation mark, this corresponds to a change in yoke play of 0.05 mm.
There must not be any sticking of the steering gear when rotated through its total stroke. Mark the definitive position of the adjusting screw with marking ink (at any place on the circumference).