Z3 rear camber/toe foobar'd

[misterpie]

Hello all,
Picked up my lovely little Z3 1.9 in April last year.
Spent a few quid on roll hoops and wind deflector (thanks Synclare) and removing the awful sub woofer that was not woofing.

Then mostly routine maintance/prevention. New antiroll bar bushes, service - oil change, plugs/leads etc.

Driving experiance is skitish to say the least and the steering wheel was at 10 to 2 when driving in a straight line. Quick visit to the tyre garage for a tracking check revealed the horror.
They adjusted the front tracking but refused to touch the back as "that's not how it left the factory".
Front is now fine, but un-nerving hacking through the lanes still. The back steps out much easier than the E36 coupe I had with the same engine so it's fun, but not safe in the winter or for the the good lady wife to drive.

It's had some plates welded in the rear axel carrier and the camber/toe is way, way off.

It's the inside pair, highlighed in yellow.

Thought I'd leave it and get round to it at some point, but while swapping the tyres for a targa rally I saw that the rear daily tryes are worn in the inside - expected, but not to this degree - almost illegal after 2k miles (had new tyres when I bought it).

Took the car to my trusted garge and they say they need to drop the rear carrier out and see what can be done (while rubbing their hands) - probably better to get a donor one to refit....

Any ideas what that plates are for (why!!!!) ? and how to fix it?
The plates are welded to the main rear carrier, but "look" adjstable .... but are they welded togther?
A basic look/compare next to my friends Z3 and camber/toe look ok, but clearly it's not :-(

Thanks!

 

[Delk]

They are toothed adjustment plates. Easy to adjust by loosening the bolt and moving the bushing one notch at a time. Not as fine as the curved and slotted type but should hold better.

https://www.ebay.co.uk/itm/BMW-E30-...-REAR-CAMBER-TOE-ADJUSTMENT-KIT-/172634243161

 

[NZ00Z3]

They are camber adjustment plates, a common modification when you lower the car. Lowering the car increases the camber and you wear the inside of the tyres quickly. The adjustment plates are installed to correct the camber. Loosen the bolts and adjust them up or down the teeth to get the setting you need.

How far out was the camber when you did the alignment?

Maybe it time to find an alignment shop that is willing to do the rear camber adjustments?

 

[misterpie]

I cannot be sure, if it was camber or toe but 8 deg was mentioned. I think they said the other side was 2 deg out. Which fits with someone trying to drift it.... not really noticed right hand bends worse than left hand.
It had show hoops and a home made sub woofer that rasped so ... good bodywork though
It's not lowered now, so perhaps it just had bigger wheels... or they put the springs back. The rest of the suspection is standard as far as I can tell.

What does (should) the camb bolt on that bracket adjust - camber or toe?
Checking by eye stood behind mine and my friends Z3 the camber looks the same - but that's not conclusive....

 

[t-tony]

The rear end track cannot be adjusted on a Z3. There is slight negative camber on the rear wheels as standard which is exacerbated by wider wheels/tyres and lowered suspension.

Tony.

 

[misterpie]

Further "scientific" investigation today while the sun is out:-
el-Cheapo bubble camber measurement tool say's I have 2.5degs POSITIVE camber on the drivers rear and 2 deg POSITIVE on the passenger side rear.

drivers rear

passenger rear

Positive camber will wear the outside of the tyre not the inside. So, looks like a toe problem as well.

Couple of planks of wood and a tape measure to check the distance between the front and rear of the tyres.

This gives me a difference of 30mm - front longer than the back. Ouch.

Problem with this measurement is the wood is bowed - possibly more/less at the front due to fouling the diff and spare wheel.

A floor level measurement - basically at the floor contact point measured 5mm.... also longer on the front.

So, the old plank across the wheel measurement - checking against the bodywork.

passenger side - clears front and rear..

Drivers rear fouls the rear bumper but clears the front, supporting the wooden plank measurements - front of the rear wheel is pointing out.

So, next step is to get under it and see if I can make any adjustments. I'll get another pair of hands to help and measure properly before and after. If so, move a little, drop it down and measure. Then plead with a garage to adjust it properly as best as possible

 

[Delk]

I used to do the alignments on my old jeeps the same way. They didn't go fast or handle the best so it didn't matter. Does give you a good idea whats going on.

The inboard adjusters are normally set vertical to adjust for camber. The outboard ones are fore and aft for toe in if installed. Since these are the toothed plate style you could easily adjust the inners a few notches and see what difference it makes to the camber.

 

[Delk]

Forgot to say. I have the opposite problem that is more common with too much negative camber from the car being lowered. This spring I will get around to correcting it but at the moment I am almost 3.5 degrees negative.
Most likely it was corrected for lowered springs and they swapped these out before it was sold.

 

[misterpie]

Most likely it was corrected for lowered springs and they swapped these out before it was sold.

That was my conclusion - I couldn't work out how lowering it, correcting the camber and then rasining it would give a negative camber - thinking that was casuing the tyre wear but it's actually the toe allignment too.
The back end is out in many different and interesting ways
I'll try to get some time this weekend but it might have to wait another week.

 

[NZ00Z3]

Don't rule out the possibility of having a bend trailing arm on the side with too much toe.