Suspension Upgrade

T

TheHoff

Member
 Wickham, Hampshire
So I'm currently sat in my Z4 as Kwikfat don't have the correct weights to align the vehicle as per BMW's strict instructions - this setup is actually better though - it's tailored to me.

I was going to get my car aligned yesterday as I entered an enormous pothole recently, damaging two of my 108s (the council will definitely be paying!) and knocked the tracking out too. However, it transpired that one of my lollipop bushes was knackered - no problem, I had a pair with new lower arms, waiting to be replaced anyway.

So today I set about fitting them today, and, with a bit of effort (the outer ball joints were VERY tight). I eventually get them fitted, along with new Meyle drop links. Unfortunately the place I usually take my cars to to get aligned, is shut, hence why I'm here.

I purchased a secondhand rear subframe and pull rods, which are in for blasting and powdercoating. Once that is done, I will press new bushes in - I've got a set for the entire back end. I need to purchase some new adjustable camber arms, as standard camber is ridiculous.

Better go - I'm being lowered :D
 
The rear subframe and pull rods have been blasted, and will be powdercoated this week - I'll fit them over a weekend during the Christmas break.

As all the exhaust and Propshaft will off, I'll pack the prop/diff joint with lots of grease - I think it is making a knock when pulling away. The NSR handbrake shoes also need some attention as they stick from time to time.

The drive shafts could do with a lick of paint too, although this may have to be done at a later date - I'll only have a weekend with the Z on the lift to effect this round of maintenance.

Oh, and I've got some BC Coilovers to fit too, and want to paint the hubs & Calipers.

I think my DISA Valve is rattling as well - marvellous!

If I had the time, I'd strip the whole car back to bare components, and rebuild...I can but dream!
 
The Kwikfat setup was pants, so I had the car aligned on a hunter thus week. Up to around 50, it feels great, but on the A3 this morning, it was anything but. The wheel is a fair bit off centre (towards the nearside) and the front of the car is wagging left and right a bit - quite off putting. I've checked the pressures and they are slightly uneven, so I'll address that and see what it's like thereafter.

Highly irritating.
 
Well I'm enjoying this thread even if no-one else is! Hoff, you sound like that's quite a bit of maintenance/repair so pat on the back, you'll have peace of mind knowing it (mostly) all done and done well and, bar a bit of tinkering, your underside is sorted for an extended period once all done. Keep posting progress - we are reading!
Stevo
 
Good to know that my efforts aren't wasted :D

Pressures now even - makes no difference - the front end still wants to gently shake its head. I'll take it back to those who aligned the car and see what they say.

I just wish I had the time to do everything in one go, rather than fanny around.
 
I decided to ignore the advice on here and went back to RFT pressures, from 32/24; it's not 100%, but nearly there. I think the wandering is going to boil to a number of things, including multiple tired components - just as well I've got that sussed!

I won't get diddly squat done this week as I'm away with work :(
 
Right, I've just taken it back to the Hunter alignment place. The figures weren't too far out in comparison to what was dialed in, except the offside rear toe - this was out by 10 minutes or so. It was dialled back in for a test drive, and whilst all was good for the first 99% of the drive, I wasn't convinced. The wheel wasn't straight for the last part of the test drive (irrespective of road camber etc). Back on the machine, and the offside rear toe is out a tad again, highlighting the trailing arm bush as the likely culprit. Just as well I've got all the rear bushes sat in my spare room!

The rear subframe should be sorted by now, so I'll chase it up and arrange collection - once that is in my mits, I'll get the new bushes pressed in and coordinate the rest of the work around Christmas and new year.
 
So I've been to the powdercoaters today, and delighted to finally get some photos up :D

d6515c7c5ffd50b0c71ffa71283fa0ee.jpg
 
Having struggled like hell to identify the correct bushes, and the lemforder (BMW OE) part numbers, I've finally been able to find a diagram - hopefully this will help others who intend to undertake a similar project.

http://2009.bmwfans.info/parts/catalog/E85/Roadster/Europe/Z4_3.0i-M54/RHD/N/2003/june/browse/rear_axle/rear_axle_carrier/

The rear subframe front left and front right bushes were purchased from mister-auto.co.uk, with the remainder from Meyle and Euro car parts. If any would like to know the specific part numbers, let me know, although this will have to wait til after Christmas; I am away for work most of this week, and off on hols thereafter :D
 
TheHoff said:
So I've been to the powdercoaters today, and delighted to finally get some photos up :D

d6515c7c5ffd50b0c71ffa71283fa0ee.jpg
Click to expand...

For parts you'll not often see they look great :thumbsup:
 
Thanks :)

I like tinkering, so I'll see them fairly often ;)

I'm really hoping to get the majority of the work done over the Christmas period - it could be a frantic few days.
 
I've not been able to make much progress due to job interviews, preparing for job interviews, and appearing in court as a witness this week.

I did tackle the replacement of the DISA Valve however - glad I did! Whilst the pin was intact, there was no spring back in the valve - it was just loose to flap around!
 
Fascinating read and well done for getting your hands oily :thumbsup:

Couple of thoughts on the wandering, is it possible something else has distorted or been damaged by the pothole? Alignment will put some correction on it but leave the underlying problem, I'm thinking dampers or strut mounts etc.
You mentioned damaged wheels I'd make a very careful check of the tyres too I've had two that had defective or damage carcases in the past and can only be spotted by checking run-out sideways and on the circumference.
I avoid mixing manufacturers or spec's for parts in any suspension re-build unless I'me sure they are going to harmonise, upgrading one part of any system often has unwanted side-effects.

But keep going, I reckon you will sort it :)
 
Thanks for the info. I have indeed dug further. The NSF damper top mount is damaged - the rubber has split. There is also a small domed nut or bolt (~8mm) that is missing - it was probably snapped off in the pothole incident. The list of items to invoice the council for is growing...

In the meantime, I'm just accepting that the handling is a bit awry, and that one of the tyres is wearing slightly unevenly. My speed is often limited to 50 by virtue of traffic, which is somewhat fortuitous.

EDIT: It's the front camber pin that is missing on the NSF top mount! THE OSF one is in place.
 
Observations about the Z4:

The exhaust bolts are made from cheese.
The space for the diff inside the subframe is a mere millimetre larger than the diff itself.
The handbrake cables WILL seize inside the hubs, necessitating the removal of the entire handbrake assembly.
Removing the rear ARB is only possible once the whole subframe has been removed, although the ARB significantly hinders removal of the subframe.
Drop links are made of clay.
The heatshield fixings were cast from iron oxide.

All that aside, I have made progress today, including removing the RTAB bushes. Aside from removing the dampers tomorrow, I shall be piecing my car back together (fingers crossed, touch wood).
 
So, I managed to get the majority of the intended tasks completed today, stand fast fitting the coilovers.

All was going swimmingly this morning, until I tackled the handbrake mechanism - the brake shields that the shoes clip onto are, quite frankly, an abortion; who in their right mind thought that this antiquated and incredibly fiddly design, was acceptable for a car produced in the noughties???!!!!!!! /RANT

As a consequence, I was unable to secure the shoes on the offside, and therefore could not put the whole rear end back together, and owing to spending so much time on the handbrake, I couldn't refit the exhaust either.

To do:

Fit coilovers
Replace rear drop links
Replace 1x brake shield
Replace 1x rear brake disc (my bad)
Replace plastic clip inside handbrake housing (stops the cables coming out of handbrake mechanism)
Refit Exhaust, after drilling out 4x broken studs
Adjust ride height
Alignment
Collapse in a snotty heap

I'm away from home during the week for the next 4 weeks, but I hope to get back behind the wheel next weekend :-)
 
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