Non run flats

D

DashBedrock

Member
 Leeds
I've just replaced my Bridgestone RF's for Michelin pilot sport 4's and was initially very happy with the improvement in handling.
But I've just had a run on the motorway at speed and the front end feels very twitchy.
Do I need to have the wheel alignment adjusted? Or can anyone advise on possible cause of this.
It tramlined on the RF's but this is totally different and is just as unpleasant if not more so.
Up to speeds of say 50 there's no issue, but at 70, Oh dear!!!
Thanks
 
Could be the alignment, could be Rear Trailing Arm Bushes, Front Lollipop bushes

Have you checked tyre pressures?

Checked wheels are torqued up correctly?

Tyres fitted in correct directions?

Front and back wheels not fixed to incorrect Axel?

When was the last time someone serviced/ took a look at the car.

Ash
 
Hi Ash,
Serviced approx 800 miles ago, Mot'd 2 weeks ago .Pressures all fine and wheels on correct axles etc. Would the rear trailing arm bushes cause a knocking? I've been reading the forum and put this down to diff clunk mentioned on several posts. The "at speed twitchyness" has literally started today. The non run flats were fitted yesterday afternoon.
Andy
 
Who did the service a BMW dealer, Specialist?

I would say you either have a bush or allignent issue if you have checked the above and all is well.

The bushes mentioned are prone to go on the z4 so that would be my first port of call.
 
Thanks for the reply Ash.
I've just looked through the mountain of receipts that came with the car and they include the following all done within the last 10 months.
Front lower wishbone arms
M3 anti roll bar
Anti roll bar bushes
Front suspension top mounts
Bilstein dampers
Eibach springs
Drop links.
I'm afraid I've only a limited mechanical knowledge
I've only had the car a week but the previous owner seems to have spared no expense when it came to maintenance.
It's puzzling me that the problem has only arisen after having the RF's replaced
Andy
 
Hmmm, know how you feel mate cos I'm having pretty much the same issues as you. I changed from run flats to non run flats on larger alloys and nowt but problems since! :headbang:
 
I've just taken it out for a spin on the motorway and I have to say it's totally dangerous above 65. I feel safer driving my Transit.
Booking it in tomorrow to check track rod ends, bushes, control arms, drop links and anything else we can think of.
Been reading a few forums and it seems likely to be one or all of the above.
 
Very brave, spending hundreds on new tyres without getting the alignment checked first?

I would invest another £80 or so and get a 4 wheel alignement check done as soon as possible if you are confident that all the other work has actually been done.
 
Thanks for the input Geezah,
Would wheel alignment cause the front end to turn to jelly at high speed?
And should alignment always be checked after putting on new tyres?
 
Defo get a wheel full 4 wheel alignment carried out by a specialist who understands and knows Z4's.

They are very sensitive to even minor out of alignment.

Mine had exactly the same issues at 60-70 ish until the car was set up and adjusted correctly.
 
Thanks Matty.
I've been researching it all day and I think that's the best option as I have receipts for all the suspension and steering components recently replaced.
And thank you to everyone else for offering advise.
It's much appreciated
Andy
 
DashBedrock said:
Thanks for the input Geezah,
Would wheel alignment cause the front end to turn to jelly at high speed?
And should alignment always be checked after putting on new tyres?
Click to expand...

I don't know what could be causing this but it would be prudent to start off with the easy fixes first. Also you want to get the best life out of your expensive tyres so I would always check alignmrnt as a matter of course.
 
Newbie question. I have had my 85 3.0 for only a couple of weeks. The manual quoted tyre pressures seem very high, (iirc 33& 36psi) I'm assuming this is for run flats. My car has 'normal' tyres, which I'm pleased about, should pressures be the same?
 
Sorted :D
Thank you to all who supplied advice on my steering from hell. 4 wheel alignment carried out and the car drives absolutely fantastic.
Tech also reported that all suspension and bushes etc are in perfect condition.
I love my Zed!!
Cheers guys
 
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