Tramlining

[stratus]

Hi all.

E86 Z4 owner, and I love the car to bits, but it's tramlining more than I'd have anticipated.

It's very eager to follow road camber and bumps in the road can send it in various directions if you're not concentrating. It's still good fun and driveable but I'm keen to get this sorted. FYI, it's on brand new non-run flat tyres.

 

[bigwinn]

Morning

A few questions-

Is the car on runflats- they exacerbate the tram lining
Which components are they planning to replace?

In my experience you can adjust the electric steering using the guides on Google (moving the adjuster ring) which tends to ease the issue but I’ve not heard of needing to replace the column to stop tram lining

 

[Rockhopper]

Reconditioned EPS unit these days is around £250. Brand new from BMW will be £££!

Many people say it’s the run flat tyres that cause tram lining but the Z4 was never criticised for any handling issues at launch so I’m feel that changing tyres just masks the real issue which is the rear trailing arm bushes.

 

[stratus]

Is the car on runflats- they exacerbate the tram lining
Which components are they planning to replace?

In my experience you can adjust the electric steering using the guides on Google (moving the adjuster ring) which tends to ease the issue but I’ve not heard of needing to replace the column to stop tram lining

Cheers for your reply. It's on non-run flats. Rears brand new, fronts nearly new.

I can't remember exactly which components they'll be replacing (I can give them a bell to find out though), my mind went blank when they said what the bill could be! I remember there's play in the front suspension.

I'll have a look into the adjuster ring, thanks.

 

[brillomaster]

easy things first - check the tyres for abnormal wear, and tyre pressures.
then check alignment - you might find you have a load of toe out somewhere, which is making you tramline.
then check for play in bushings - might be a bad RTAB as mentioned.

then once all those things are good, if you're still tramlining, then consider steering racks.

as an aside - my current car sniffs out all the road imperfections and is all over the place... but i know i have a load of rear toe out which i'll be getting rectified before doing anything else!

 

[stratus]

easy things first - check the tyres for abnormal wear, and tyre pressures.
then check alignment - you might find you have a load of toe out somewhere, which is making you tramline.
then check for play in bushings - might be a bad RTAB as mentioned.

then once all those things are good, if you're still tramlining, then consider steering racks.

as an aside - my current car sniffs out all the road imperfections and is all over the place... but i know i have a load of rear toe out which i'll be getting rectified before doing anything else!

Thanks for your reply

 

[stratus]

Just rang up to recall what was found today.

They found play in the front lower arms which will be replaced in a week or so, with an alignment following that.

 

[AveZ4coop]

I have found over the years that having either of the following noticeably increase tramlining on my e86:
-one tyre with slightly low pressure (Including a back tyre)
-poor alignment
The car always sniffs out any bumps in the road and follows them like a bloodhound, but keeping tyre pressures monitored and regular 4 wheel alignment keeps the worst of it at bay. I will say that when I moved to non run-flats it did improve it at a stroke, but an element of tram-lining remains.

 

[stratus]

I have found over the years that having either of the following noticeably increase tramlining on my e86:
-one tyre with slightly low pressure (Including a back tyre)
-poor alignment
The car always sniffs out any bumps in the road and follows them like a bloodhound, but keeping tyre pressures monitored and regular 4 wheel alignment keeps the worst of it at bay. I will say that when I moved to non run-flats it did improve it at a stroke, but an element of tram-lining remains.

Cheers, I will definitely check the pressures again today although am sure they're all OK. Alignment booked in just over a weeks time alongside replacing the lower suspension arms at the front.

 

[thecremeegg]

Like others have said, tyre pressures are a big one but these cars do tramline a lot, worse on bigger wheels.
I do think the EPS has something to do with it to a degree as since swapping my (admittedly dodgy) EPS out to hydraulic I do have to fight the wheel a lot less.

 

[bigwinn]

If the rear lollipops are shot (check them if you can before they replace them) that will make a difference to the car finding the tracks

 

[raymond.harper]

Could be the steering rack preload. Big thread on the steering issue https://z4-forum.com/forum/viewtopic.php?t=100725&start=450

 

[MikeyH]

Mine has done it ever since I bought the car, I’m on 18” non run flats. After I had the tracking done and put the tyre pressure up to 31f and 33r it helped a lot but if I’m not concentrating the car is all over the place. Some roads are worse than others.

 

[stratus]

Thanks everyone. It's quite re-assuring to know these cars are pretty lively anyway.

 

[Mr Tidy]

Both my 3 litre E86s were prone to it, the first much more so than the second.

Admittedly they were both on Bridgestone run-flats, but new front control arm bushes on my first one improved things no end.

To be fair they weren't significantly worse than the 123d I had previously, especially when it had worn tyres or the pressures had dropped slightly.

 

[stratus]

Both my 3 litre E86s were prone to it, the first much more so than the second.

Admittedly they were both on Bridgestone run-flats, but new front control arm bushes on my first one improved things no end.

To be fair they weren't significantly worse than the 123d I had previously, especially when it had worn tyres or the pressures had dropped slightly.

Cheers. Front control arms in to be done in a week so will see how this affects things. Good to know that they can generally be pretty prone to it.

 

[MikeyH]

Interested in your opinion when they are done

 

[stratus]

Front lower suspension arms & bushes changed this morning. It is certainly feeling a lot better so I'm pleased.

 

[enuff_zed]

Hey all.

Front lower suspension arms & bushes changed this morning. It is certainly feeling a lot better so I'm pleased.

However, there is still some twitchiness, an eagerness to 'steer itself' sometimes, which the mechanics think is still a steering column issue, although he has seen a lot worse.

What I'll probably do is leave it for a few months and monitor how much it bothers me whilst ticking off some other jobs I want to get done. If come Spring/Summer time it's annoying me, I'll book it in to a Z4 specialist (probably Zed Shed, as it's down the road from me) to look into it a bit further and consider options.

I would suggest you save yourself a bit of cash, search for 'sticky steering' on here and try adjusting the spacer ring between the motor and the column.
Simply crack the two torx bolts, make an indelible datum mark across the motor and spacer, then tap the bottom of the spacer towards the pedals about 5mm. Tighten the bolts but don't panel up. Take it for a run and see what you think. It may need another tweak to make it perfect.