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Tim Hancock Tim Hancock is offline
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Join Date: May 2004
Posts: 9,218
Originally Posted by RWebb View Post
- Anybody know if this is possible? worthwhile??
Randy, FWIW, there are basically 4 items that could benifit from lubrication in the rack, three of which you could get some grease on while it is still in the car.

1) The pinion gear and rack teeth- One could get some grease on the rack teeth by removing the tie rod rubber boots and simply smear some grease on the rack while turning the rack from lock to pinion gear was bone dry and showed some wear.

2) The puck- It could be removed and some grease could be smeared on it... It is spring loaded to contact the back of the rack applying a load to constantly maintain positive contack of the rack teeth and the pinion. It made to slide out of a wear resistant material and while greasing it is not a bad idea, it probably does not really need any to do it's job..... Mine had wear and was dry, but it still had plenty of material left and still kept lash out of my system when I re-asssembled it.

3) The lower ball bearing- It can be greased by removing the cover and grease injected or forced into it from below..... Mine was bone dry and had SIGNIFICANT wear which was the CAUSE of the freeplay in my rack. Mine required replacement.

The pinion has slanted teeth and when it is turned by the steering shaft it tries to screw it self up or down depending on which way the wheel is being turned. If the bearing is good, it resists this up/down motion and the turning pinion which is contacting the teeth of the rack, instantly drives the rack left or right. When the bearing is bad, it allows the pinion to ramp/screw itself up or down, taking up play in the bearing, prior to driving the rack...hence free play at the wheel.

4) The upper needle bearing- It is impossible to grease unless the whole rack is removed and tore apart. While it may be dry, IMO, it would not have much affect on steering freeplay or feel. IOW, it is probably the least important of the four moving parts in the rack...... Mine was bone dry.

My rack is still performing flawlessly since this was originally posted and I am quite confident it will continue to do so for a long time.
German autos: '79 911 SC, '87 951, '03 330i, '08 Cayenne

Men do not quit playing because they get old.... They get old because they quit playing.
Old 03-17-2008, 04:48 AM
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