E85/E86 Steering Problems (Solved)

[ryushe]

Maybe the best route is to get yours reconditioned, even if it means sending it abroad to be done ?

Looked into that as well, 3 different companies here in NL tell me that reconditioning in the case of the Z4 steering rack is no more than replacing seals and regreasing the thing. They can't do s**t about any (even slight) wear in the teeth of the gears, which is what I seem to be suffering with.

Next stop is eBay, and hoping that what I find there is in decent shape. Although a cursory glance finds results for racks from cars that are all 100k+ miles

[MikeyH]

Autodoc sells a LHD rack by Lizarte for £222.15. including VAT You will need to return your old one though. It says free delivery but may only be the UK. Sorry if we have been here before but it is a long thread and I may have lost the thread.

[ryushe]

Autodoc sells a LHD rack by Lizarte for £222.15. including VAT

Yep, all of them are out of stock. Checked if that's actually the case too by calling the companies listed on Autodoc (ERA, Delco, Elstock)

bmwz4steeringrack.PNG (66.9 KiB) Viewed 743 times

[ThePocketGT]

Thanks Lee, adjustment made and a vast improvement in the handling. My steering always felt really loose and I found the ring to be in the slackest of positions. I knocked the ring round by 20mm and the steering feels soo much heavier. Test drive for a week and see if it needs more tightening or realising.

Thus is certainly worth doing.....

[2.5tdi]

I adjusted ring 10-12mm clockwise direction which should mean lighter steering wheel. It wasn’t sticking so much when straight but was only heavier. It is perfect now but micro assist in straight direction at ~100km/h is even worse now. It makes car awful to drive.

[perttu]

My current understanding is that steering issues (sticky/loose/twitchy/micro-adjusting) come down to two factors: the EPS ring adjustment and the steering rack preload. Additionally, issues with steering rack wear will affect the steering. Both the rack preload and EPS ring need to be properly adjusted and in correct relation to each other to optimize the steering.

Here's what I've learned so far, mostly from forum member @Maklo
- lift the front wheels up in the air, engine off (=no EPS active)
- adjust the steering rack preload as shown in https://youtu.be/9KUJOvYR23A. You don't need to take the rack out of the car to do this. Turn the steering wheel from full left to full right position and make sure the steering wheel movement is equally smooth in all positions. Adjust the preload as necessary until movement is smooth.
- you also might want to clean and lube the rack if it's dry, easiest to do while the rack is out
- adjust the EPS ring just slightly below the sticking limit, probably needs trial and error. The fact that ambient temperature has a role on how the steering behaves, does not exactly help.

Related thread: viewtopic.php?t=141290&start=30

[2.5tdi]

My current understanding is that steering issues (sticky/loose/twitchy/micro-adjusting) come down to two factors: the EPS ring adjustment and the steering rack preload. Additionally, issues with steering rack wear will affect the steering. Both the rack preload and EPS ring need to be properly adjusted and in correct relation to each other to optimize the steering.

Here's what I've learned so far, mostly from forum member @Maklo
- lift the front wheels up in the air, engine off (=no EPS active)
- adjust the steering rack preload as shown in https://youtu.be/9KUJOvYR23A. You don't need to take the rack out of the car to do this. Turn the steering wheel from full left to full right position and make sure the steering wheel movement is equally smooth in all positions. Adjust the preload as necessary until movement is smooth.
- you also might want to clean and lube the rack if it's dry, easiest to do while the rack is out
- adjust the EPS ring just slightly below the sticking limit, probably needs trial and error. The fact that ambient temperature has a role on how the steering behaves, does not exactly help.

Related thread: viewtopic.php?t=141290&start=30

Great answer. Thanks!
It is possible to lube steering rack on car? Also which lube is best to use?
Are there any software updates for eps? That could help?

[perttu]

It is possible to lube steering rack on car? Also which lube is best to use?

To certain extent it is possible. You need to remove the steering rack boot to uncover the rack. Tie rods might need to come off as well. When you have exposed the rack, turn the steering wheel to extreme position on the driver's side. This will result in most of the rack being visible. Then just clean it and apply moly grease on the rack.

Are there any software updates for eps? That could help?

The EPS module looks like it's flashable, but so far I've had no success with EPS and WinKFP. There is a newer ZUSB for EPS shown in WinKFP, but at least for me all I get is "no response from control unit" error in WinKFP. I'm planning to try out ISTA/P instead, but I don't have an ICOM interface which is needed to program modules with ISTA/P. I'll probably look into that later.

[perttu]

One thing to note about steering rack preload adjustment, and also a word of warning, if you have the twitching or microadjusting steering issue, it does not automatically mean that you need to tighten the steering rack preload. Even though it may sound counter intuitive, it also can be the other way around, you might need to loosen up the rack preload. The theory is that too heavy preload on the rack will mess up EPS which starts doing adjustments. You will feel if there's heaviness or notchiness in the rack when you turn the steering wheel left and right through center while wheels are in the air.

[Emanresu]

So I went to do this as my steering feels a bit odd at motorway speeds. Sort of constantly sticking/unsticking, only ever so slightly but just constantly adjusting like it’s catching a magnet on/off.

I managed to undo the torx bolts no issue, however the ring seemed to be seized in place? The hole that people were using to put a screw driver was completely inaccessible as it was up in the 2 o'clock position, does this mean it’s already been fully adjusted?

If so, would I need a new rack to fix the issue?

[enuff_zed]

So I went to do this as my steering feels a bit odd at motorway speeds. Sort of constantly sticking/unsticking, only ever so slightly but just constantly adjusting like it’s catching a magnet on/off.

I managed to undo the torx bolts no issue, however the ring seemed to be seized in place? The hole that people were using to put a screw driver was completely inaccessible as it was up in the 2 o'clock position, does this mean it’s already been fully adjusted?

If so, would I need a new rack to fix the issue?

That does sound as though it's at its full travel. Just checked on the one laying in my garage. They usually have a good 10mm of open slot showing past the bolt, which equates to at least 20mm of adjustment left.
However, before you get too deep into it, there is a possibility it has been adjusted too far in the past. There is a sweet spot either side of which you start to get odd behaviour.
So you could try moving it back. Mark a datum line across it before you move it, then pull the bottom of the ring back towards you until you have a good 25mm gap between the datum marks. It will likely be too far, but it will allow you to then tweak back 5mm at a time to see if it improves.
It's so easy to adjust, if you leave the panels off you can go for a drive and do several adjustments as you go.

[Emanresu]

So I went to do this as my steering feels a bit odd at motorway speeds. Sort of constantly sticking/unsticking, only ever so slightly but just constantly adjusting like it’s catching a magnet on/off.

I managed to undo the torx bolts no issue, however the ring seemed to be seized in place? The hole that people were using to put a screw driver was completely inaccessible as it was up in the 2 o'clock position, does this mean it’s already been fully adjusted?

If so, would I need a new rack to fix the issue?

That does sound as though it's at its full travel. Just checked on the one laying in my garage. They usually have a good 10mm of open slot showing past the bolt, which equates to at least 20mm of adjustment left.
However, before you get too deep into it, there is a possibility it has been adjusted too far in the past. There is a sweet spot either side of which you start to get odd behaviour.
So you could try moving it back. Mark a datum line across it before you move it, then pull the bottom of the ring back towards you until you have a good 25mm gap between the datum marks. It will likely be too far, but it will allow you to then tweak back 5mm at a time to see if it improves.
It's so easy to adjust, if you leave the panels off you can go for a drive and do several adjustments as you go.

Thanks for the speedy reply!

When I had the bolts loosened, I tried to adjust either way and the ring was completed solid, I could rock the entire motor a few mm but the ring would not slide? I managed to prise the bolt from the connector in case it just needed the seal broken, didn’t change anything.

This is viewed from the bottom.

[enuff_zed]

So I went to do this as my steering feels a bit odd at motorway speeds. Sort of constantly sticking/unsticking, only ever so slightly but just constantly adjusting like it’s catching a magnet on/off.

I managed to undo the torx bolts no issue, however the ring seemed to be seized in place? The hole that people were using to put a screw driver was completely inaccessible as it was up in the 2 o'clock position, does this mean it’s already been fully adjusted?

If so, would I need a new rack to fix the issue?

That does sound as though it's at its full travel. Just checked on the one laying in my garage. They usually have a good 10mm of open slot showing past the bolt, which equates to at least 20mm of adjustment left.
However, before you get too deep into it, there is a possibility it has been adjusted too far in the past. There is a sweet spot either side of which you start to get odd behaviour.
So you could try moving it back. Mark a datum line across it before you move it, then pull the bottom of the ring back towards you until you have a good 25mm gap between the datum marks. It will likely be too far, but it will allow you to then tweak back 5mm at a time to see if it improves.
It's so easy to adjust, if you leave the panels off you can go for a drive and do several adjustments as you go.

Thanks for the speedy reply!

When I had the bolts loosened, I tried to adjust either way and the ring was completed solid, I could rock the entire motor a few mm but the ring would not slide? I managed to prise the bolt from the connector in case it just needed the seal broken, didn’t change anything.

This is viewed from the bottom.

Hmmm. OK, well the motor is bolted directly to the column so you can't mess that up.
I would try a couple of turns on the bolts so you can move the motor over a little, then try tapping a thin blade between the column and the spacer. It must be just sticking.

[Emanresu]

I don’t know what voodo you did mate, but I thought I’d give it another crack after you said, so I loosened it as before and straight away it adjusted freely so just going through adjustments, then a quick drive, adjust etc to get it perfect! Thanks for your help

[enuff_zed]

I don’t know what voodo you did mate, but I thought I’d give it another crack after you said, so I loosened it as before and straight away it adjusted freely so just going through adjustments, then a quick drive, adjust etc to get it perfect! Thanks for your help

No voodoo mate.
I'm just on the Steering Committee.