notchy steering

seanodwyer said:
Looks like I've solved my sticky steering. It used to come on regular as clock work on my journey home. But tonight after having the uv joints on the steering rack greased I've had the most enjoyable journey home in a year; toasty toes and no sticky steering!!!

Just on another note my battery is completely dead (won't start the car even after only been switched off for five minutes) and this did not seem to affect the steering. So well worth trying the grease the uv joints (two of them) for anyone experiencing this annoying issue.
Click to expand...
Do you know how they greased the u/j as they don't have a grease nipple. or are we talking about the joint at the end of the track rod.?
 
Just to clarify what's involved, as stated above there were problems with the pre-facelift column internals that mean they get tight under certain hot conditions. This forces the electric servo motor on the column to work harder further heating the unit. The control unit has a thermal cut out to protect it from overheating which reduces the servo assistance it gives in large % steps until the control unit cools. The combined effect of the excess friction and erratic servo assistance leads to the sticky notchy steering effect.

Reducing friction in the full steering system reduces the work that the servo has to do leading to a cooler servo and controller thus reducing the chances of sticky steering. drilling and lubricating the steering column main shaft and gears seems to work for some as it reduces friction in that part of the system. I found that lubricating the lower part of the steering gear, i.e the bottom shaft and two universal joints in the engine bay, worked instantly for me and has never returned as that was clearing causing sufficient friction to overwork the servo. Worth a try as it's worked for sever members per this thread http://www.z4-forum.com/forum/viewtopic.php?f=2&t=47676&p=690946&hilit=+column#p690946
 
I have a 2003 Z4 2.5i with electric steering and sticky steering problems when it get's hot. solution for me was to drill a hole in the steering colum and spray oil in it. i used this thread: http://forums.bimmerforums.com/forum/showthread.php?1896932-DIY-Sticky-Clunky-Steering-Fix/ .
I am driving this car for 3 years now and the steering hasn't been as good as this before. I did this 2 week ago and today it's a warm day but steering is still perfect.
 
LeonSp said:
randyf said:
OK I am going to lube the joints and lube the worm driven gear via drilling small hole. thx
Click to expand...

That should work.

What I find interesting is the way this happened before I greased the steering column. I would park the car facing the sun on a hot day with the top up. The car was parked in a large shopping parking lot. Driving around the parking lot while the steering and the servo was hot I never had any sticky or notchy steering while at low speeds. The servo assist never cuts out from the heat during low speed driving. In my case the worm and ring gear in the column stuck because of too tight of tolerance while hot and lack of lubrication. This sticking happens at higher speeds when the power assist is reduced automatically by the steering ECU. It was even worse with the sport mode on which reduces steering assist even more. So while the steering is programmed to reduce assist at high speeds the worm and ring stuck together causing the feeling of notchiness. Not that the servo overheats and cuts out. BMW did not change the servo drive in the column on the facelift model. They changed the tolerances between the worm and ring gear, made the worm gear smoother, and changed the type of grease used for this assembly.
Click to expand...

You are correct to a degree, the tight worm gear was ONE of the causes of excess friction in the system and no doubt the cause of your particular sticky steering problem but there are several parts that can give the same effect, all revolving around tight/dry components including worm gear, shaft bearing and lower shaft/universal joints. The new worm gear/lube was ONE of three iterations of steering column the final being fitted to the facelift in around 2006. Other mods included shaft bearing material and the controller. Technical references have been posted supporting this in the past. The below link takes you to a workshop training manual describing the system in detail including the controller function which shuts the assistance down in stages in response to overloading (e.g through friction in the system) and overheating see page 14. This does not mean that everybody with mechanically sticky steering ends up with the controller/servo shutting down, but that will be the outcome of more extreme resistance/overloading and overheating. Hope this assists,
http://www.bmwclub.lv/files/06_E85_Chassis_Dynamics.001.pdf
 
You must log in or register to reply here.
Back
Top Bottom