M340i G21 Steering issue or bad by design?

M340i G21 Steering issue or bad by design?

Author
Discussion

spanky3

Original Poster:

261 posts

148 months

Monday 7th October
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If I turn left or right in my G21 M340i, the steering doesn't quite centre itself afterwards and the car continues to turn unless I manually straighten the wheel. Driving in a straight line is the same - I can set the steering a few degrees left or right and the car makes no attempt to straighten up.

Is this normal for G20s, or an alignment or steering issue?

I bought it a fortnight ago from a (distant) main dealer and my local dealer will charge me £250 if they decide it's not a warranty issue.

sjb993

79 posts

245 months

Tuesday 8th October
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I have the same car and same year, my steering wheel always re-centres itself perfectly. Have you checked the tyre wear on the tyres to see if it's even? If not perhaps you need a re-alignment?

ARHarh

4,279 posts

114 months

Tuesday 8th October
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First port of call would be an alignment check. That should spot anything amiss.

spanky3

Original Poster:

261 posts

148 months

Tuesday 8th October
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Thanks for confirming it's not every car. The car tracks evenly left and right and isn't at all jittery or nervous, it just doesn't centre so I don't think its toe but it could be a caster issue I guess. My hunch is either software or a VSS rack issue.There are quite a few other reports of the same behaviour including at least one video but it doesn't seem to be every car. My worry is the dealer which just say it's fine and charge me £200,

marcusjames

783 posts

268 months

Wednesday 9th October
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I have the M3 touring and it does this. I've had the alignment and steering calibration done and no difference.

I admit it's weird, but you get used to it.

The BMW tech showed me documentation about how the steering motor is almost non-existent at 15 degrees from centre. That is left for the driver to correct or it feels the driver is fighting it.

spanky3

Original Poster:

261 posts

148 months

Wednesday 9th October
quotequote all
Thanks Marcus, I'd not thought of M3s, good and bad I guess that you have this too. But with that info I found this page:

https://g80.bimmerpost.com/forums/showthread.php?t...

Which has a mix of people with this issue who've been told by dealers it's normal, and people without the issue saying it sounds like an issue.

All this leads me to think that it's not deliberate behaviour but a common trait of a bad design. My dilemma now is whether to cancel my dealer appointment on Friday, as while this cannot be the behaviour BMW designers intended I'm increasingly sure they'll claim its fine.

Ed.Neumann

598 posts

15 months

Tuesday 12th November
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I wonder, BMW have had issues with the steering clonking on the last 3 series, there is an adjustment on the rack itself, if it is slightly too lose the grommet inside will allow the noise/clunking, if you slightly over tighten it you get exactly what you describe.


This is the repair kit..

https://www.ebay.co.uk/itm/283673113181


Not saying yours needs a repair kit, but I would consider looking at your rack and see if you can loosen it a bit.
Mark it, move it 1/8th of a turn, see what happens, if it sorts it great. If not loosen a smidge more and see if that helps, if you start to get a clunk you have gone too lose.

But I bet BMW have over tightened it compared with the F30/31 to make sure there is no clunking.

ucb

1,039 posts

219 months

Tuesday 12th November
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My Civic EP3 Type R used to do this.
Steering would stick just off centre and need to be 'corrected'. Honda would replace the rack under warranty allegedly but i just got rid as the car wasnt suitable for me.

Monkeylegend

27,206 posts

238 months

Wednesday 13th November
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BMW have also had a recall for steering issues amongst other issues as outlined in this thread.

Problems with steering UJ and spindle.

Third post down.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

rottenegg

795 posts

70 months

Friday 15th November
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Ed.Neumann said:
I wonder, BMW have had issues with the steering clonking on the last 3 series, there is an adjustment on the rack itself, if it is slightly too lose the grommet inside will allow the noise/clunking, if you slightly over tighten it you get exactly what you describe.


This is the repair kit..

https://www.ebay.co.uk/itm/283673113181


Not saying yours needs a repair kit, but I would consider looking at your rack and see if you can loosen it a bit.
Mark it, move it 1/8th of a turn, see what happens, if it sorts it great. If not loosen a smidge more and see if that helps, if you start to get a clunk you have gone too lose.

But I bet BMW have over tightened it compared with the F30/31 to make sure there is no clunking.
Completely different rack to the F series, but the Fs also exhibited exactly the same steering traits. My 2016 has done exactly as the OP describes since I bought it on 38K miles....but not consistently. Some days the steering is perfect, and some days it's slightly tardy to self centre.

I just put it down to runflats as it's had the repair kit done and a lot of other suspension work done since, and it still does it.

It's just how (some) of them are. I've driven a 22 plate G22 and that had exactly the same steering feel and centering behaviour.

You could be onto something with the rack preload though. That could explain the inconsistency. It's a long drawn out process involving many tools and gauges to set the correct twist torque on the rack.



Ed.Neumann

598 posts

15 months

Friday 15th November
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rottenegg said:
You could be onto something with the rack preload though. That could explain the inconsistency. It's a long drawn out process involving many tools and gauges to set the correct twist torque on the rack.
I just bought a tool off eBay for £15 and adjusted it 1/8th of a turn at a time until it felt right.

Took about and hour and 5 adjustments.


rottenegg

795 posts

70 months

Saturday 16th November
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Ed.Neumann said:
rottenegg said:
You could be onto something with the rack preload though. That could explain the inconsistency. It's a long drawn out process involving many tools and gauges to set the correct twist torque on the rack.
I just bought a tool off eBay for £15 and adjusted it 1/8th of a turn at a time until it felt right.

Took about and hour and 5 adjustments.
Yeah me too. I got the Thyssenkrupp chinese copy tool from Amazon for a tenner and fitted the tensioner block repair kit myself. In the end, setting the cap flush to the rack housing gave the best feel and shifted the clonks. BMW dealers will want a couple of hours labour and the end result is hit and miss, in spite of following the prescribed process from Thyssenkrupp.