Which is worse - Twitchy steering or Sticky steering?

Z

Zikim

Active member
I have "twitchy steering" that is when I drive above 60mph the steering wheel oscillates from right to left about once every 2 seconds or so - those who have had it or experienced it will know the feeling. My sport button adds weight at low speed but hardly anything is noticeable at higher speed.

This morning driving to work at a temperature of 5 degrees twitchy steering as usual. This evening drove home at a glorious temperature of 23 degrees and oscillation has gone - only to be replaced by sticky steering!!! The sticking steering is not that bad and the effort to overcome is not great, in fact the weighting of the steering is now a lot better - probably the reason why the oscillation/twitchy steering has stopped.

Had my 3.0iSE 2004 zed into BMW stealer a couple of weeks ago who have said they do not do software updates on the EPS alone but they can only update all the software on all the ECU's at a cost of £200 and will not cover any cost if any of the ECU's fail and need replacing. I am looking at updating the EPS software myself using SSS Progman but do not know if this will cure the twitchy steering and may have the EPS fail altogether. I have asked on this forum if anyone has done this using SSS Program but no-one seems to have done this!

The software update may relieve some of the sticking steering issues (I would have to other mods such as grease nipple on EPS drive). I do not know if the software update will solve the Twitchy steering or give heavier steering at speed with the sport button on?

So which is best to live with - Twitchy or Sticking steering?
 
I have been suffering from this issue until recently.
You may have wear in steering or suspension bushes ( I take it you don't have any warning lights up or a known EPS fault?).
With wear I believe that the wheels can wander and affect the torque sensor calling it to assist as the wheels load the steering. This causes the EPS to assist and then stop assisting even when driving in a straight line. 60mph I believe is the approx speed where the gain/assist from the EPS appears graetest. It was this speed I had issues with
I have replaced the rear front bushes with poly bushes adjusted to a more toe in setting and the issue has stopped :)

See the post and see what you think

http://www.z4-forum.com/forum/viewtopic.php?f=2&t=76370
 
Thanks Toe-side, I have replaced the front control arms and bushes, drop links arb bushes and on the rear RTAB's and drop links and new bilstein shocks all round and new rear springs.

Interestingly the twitchy steering is now stopping in warm weather to be replaced by sticky steering due to, I believe the extra resistance in the steering system or the reduction of power assistance.

Toe-side what have you increased your toe-in to on your front wheels?
 
Mmm cannot give you figures sorry
I have been experimenting with 'toe in'. I need to get a 4 wheel alignment check again to get a baseline now that I have everything changed.
I have been using string, a couple of axle stands. a digital micrometer, tape measure and a straight edge! :oops: Just increasing a little more toe in and comparing what the effect was. Toe in obviously helps the straight line stability.

The toe in adjust helped but didn't solve the issue completely until I changed the bushes. It might be worth checking alignment and ask for max toe (in within setting limits) and see what happens if you are not into experimenting
 
Please check your hydro bearings and your tie rod heads. it could be to much play on it.

Sticky Steering comes from the column, with no faults or errormessages.
A friend of me solved this problem of sticky steering. He fixed my column and the column of my wives z4.

Later, I will post some pictures.

regards Instructor
 
Zikim said:
hopz121 said:
Have you had an alignment done recently?
Click to expand...
Yes, alignment has been done on Hunter machine
Click to expand...

Do you have a print out of the settings they used?

Sounds to me like an alignemtn issue if you have replaced all of the bushes.


Ash
 
E85-Instructor said:
Please check your hydro bearings and your tie rod heads. it could be to much play on it.

Sticky Steering comes from the column, with no faults or errormessages.
A friend of me solved this problem of sticky steering. He fixed my column and the column of my wives z4.

Later, I will post some pictures.

regards Instructor
Click to expand...
The hydro bearings (front control arm bushes) have been replaced by Meyle HD units and rechecked only last week for movement or play of which there was none. Tie rod ends checked and are all ok with no play - car also passed MOT last week with no failures. One degree of movement at steering wheel is instantly felt and seen at the road wheel.

There are no faults or errors either displayed or in the memory.
 
hopz121 said:
Zikim said:
hopz121 said:
Have you had an alignment done recently?
Click to expand...
Yes, alignment has been done on Hunter machine
Click to expand...

Do you have a print out of the settings they used?

Sounds to me like an alignemtn issue if you have replaced all of the bushes.


Ash
Click to expand...
The settings used are for E85 lowered suspension with 18" wheels and all are in spec with the following measurements
Front LH RH
Camber 1deg 05' 1deg 00'
Toe 0deg 07' 0deg o7'

Rear LH RH
Camber 2deg 45' 2deg 35'
Toe 0deg 11' 0deg 12'
 
I would suggest reducing rear camber and going down the M settings route, this will give you alot more stability on the straights and should cure the twitchy steering. :)
 
hopz121 said:
I would suggest reducing rear camber and going down the M settings route, this will give you alot more stability on the straights and should cure the twitchy steering. :)
Click to expand...
The rear camber was reduced to 1deg40' on both sides last night and it has made no difference! Thanks anyway for the suggestion.
 
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