Rear tracking?

UK forum for general and technical discussion about the Z3 roadster

Moderator: Gazza

Post Reply
Parki
Joined: Sun 02 Feb, 2014 17:42
Posts: 70

  Z3 roadster 1.9

Rear tracking?

Post by Parki » Tue 21 Nov, 2017 15:40

My '97 1.9 failed its MOT due to tyre wear- all 4 were worn around outer of tread - I was told this is 'toe out' & have just bought 4 new tyres & asked for 4 wheel tracking to be done. Mechanic told me no rear adjustment is possible but rears are at factory setting.
Haynes manual states rear tracking is by adjusting trailing arm. So can rear tracking be adjusted?

User avatar
colb
Joined: Sat 05 May, 2012 23:46
Posts: 586

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Rear tracking?

Post by colb » Tue 21 Nov, 2017 16:12

No adjustment for rear tracking unless you fit an aftermarket kit.
Check out all the rear suspension bushes to see if any are worn, if so replace to bring it back to factory specs and see if that makes a difference to tyre wear. Only other thing if the wheel is out would be accident damage to the components.
http://www.realoem.com/bmw/enUS/showpar ... Id=33_0998

I do note that the parts diagram lists two types of bushes that are available, 1 set shows eccentric which may indicate there is some adjustment using eccentric bushes. No doubt a bush expert will chip in to clarify.

Just found this which explains some adjustment with eccentric bushes
https://www.youtube.com/watch?v=jFsZek_6Gig
Colb
1999 BMW 1.8 Z3
1998 Honda Deauville NT650V

Brian4
Joined: Mon 19 Dec, 2011 19:02
Posts: 536

  Z3 roadster 3.0i
Location: Hinckley

Re: Rear tracking?

Post by Brian4 » Tue 21 Nov, 2017 20:43

The Haynes manual is for the' E36 and includes Z3'?

If this is the case the Z3 has the rear set up based on the E30 and the same as the compact E36 which cannot be adjusted. As colb says teh rubber bushes are probably worn by now so the alignment wont be as good as when it left the factory.
Brian
3.0I Topaz Blue


2000 E36/7 Z3 3.0i
2016 F31 335d
2015 F21 118i

vzh7gk
Sponsor 2018
Joined: Fri 05 Feb, 2010 13:12
Posts: 106

  Z3 roadster 1.9
Location: Cheltenham, UK
Contact:

Re: Rear tracking?

Post by vzh7gk » Wed 22 Nov, 2017 10:04

Graham (G4FUJ)
Prescott marshal and Hill Controller
Found another Z3 so back here after a long break :) 1999 1.9, Palmetto Green
1 Morgan 4/4 (selling in Spring) and a Land Rover 90 (keeping forever)

Parki
Joined: Sun 02 Feb, 2014 17:42
Posts: 70

  Z3 roadster 1.9

Re: Rear tracking?

Post by Parki » Wed 22 Nov, 2017 15:10

Thanks for all help - you are right about Haynes manual. Now I will have to apologise to mechanic.

Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Re: Rear tracking?

Post by Buzzy-Beans » Sat 25 Nov, 2017 12:22

From my experience most independent rear suspension is adjustable to some degree.

Many years ago I bought a new Escort XR3i Turbo and for a few months driving it in the wet or ice was a white knuckle experience. I then noticed that the rear tyres were feathering and so I started undertaking some research. Ford said the rear suspension wasn't adjustable, but then on digging further I discovered that it was simply by fitting the correct thickness shim washers! In the end my car was sorted out and a further 22,500 similar Escorts were called in for modifications!!

Oh and only take what you read in any Haynes Manual with a pinch of salt! In Land Rover Series and Defender circles they are termed as the Haynes Manuals book of lies!!

therealdb1
Joined: Tue 25 Jun, 2013 22:47
Posts: 247

  Z3 roadster 2.0

Re: Rear tracking?

Post by therealdb1 » Sat 25 Nov, 2017 14:08

Anything is adjustable it just depends how much effort you want to go to to adjust it.
When the manual states that the suspension is not adjustable they mean that the geometry is fixed from the factory but as has already been said you can change certain bushes and arms that will change that "fixed" geometry.
Having said that this is a 20 year old car now so unless you know that the standard bushes have been replaced recently and they are as they should be that is the first place to look before tweaking any alignment angles.

Buzzy-Beans
Joined: Tue 14 Nov, 2017 15:01
Posts: 15

  BMW other

Re: Rear tracking?

Post by Buzzy-Beans » Sat 25 Nov, 2017 17:18

If you don't know this already, here is a fail safe tracking test that you can do with your eyes closed.

Having spent many a long year working for several of the Worlds leading major tyre manufacturers we were always looking for ways to educate the customers about the set up of their cars.

If a tyre is running true and in total alignment then the tread wear should in most cases be even but if it isn't then the vehicle in question has some kind of problem.
A very simple and sure fire way of highlighting any wheel/suspension alignment fault is to lightly run the palm of your hand over the tyres tread, if with the exception of the tread itself, the undulations of the tyre feel relatively smooth then everything is OK, however if there are sharp edges to any edge of each tyre block then as sure as eggs is eggs, something isn't right.

By way of proving this, if you feel the tyre tread of a rigid axle rear axle then there won't be any sharp edges, unless that is, it is fitted to a vehicle that has been driven sideways in a power slide around an oval track!

Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2122

  Z3 roadster 1.9

Re: Rear tracking?

Post by Del » Sat 25 Nov, 2017 22:55

Unusual as the Z3 has a certain amount of natural OE negative camber (rear) and the usual problem is extra wear on the inside of the rear tyres when people have lowered the car or have soggy, worn suspension/springs. Is it possibly the front that has the "tracking" problem and the tyres have been switched at some point?

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 4 guests