The effectiveness of a proper suspension overhaul..

[GuidoK]

This is for a porsche 996, but from experience I know the same goes for a z4 (except paying porsche money of upgrades ), but he puts it in better words than I ever could

www.youtube.com/watch?v=0KLBGVClpX0&t

enjoy

[Ducklakeview]

Have to concur. Recently did ALL of the rear bushes on mine, and then had an alignment done... Transformation is an understatement...

Mike

[Chris_D]

interesting guido.
but i got distracted by this in the youtube sidebar halfway through....
https://www.youtube.com/watch?v=3y0UR7Fjfsc
Remember watching this as a 9 yr old. happy days. snif.

[tomscott]

Still £6+k for sus upgrades.... gulp

[GuidoK]

Still £6+k for sus upgrades.... gulp

If you do it on a z4 budget:
KW V3 £1700
http://www.ebay.co.uk/itm/KW-coilovers- ... 2124637048

H&R swaybar kit £360
http://www.ebay.co.uk/itm/H-R-Sport-Swa ... 2648706414

Strongflex full suspension bush kit (includes subframe, diff etc etc) £332
http://www.strongflex.eu/en/e46/735-ful ... 19143.html

So little under £2400 with excellent components; thats over 3600 less than the 911
Thats the difference between porsche money and bmw money

As for the work: I had all the z4's rear axle bushings removed in about 3 hours! I just dropped the whole rear axle (ok that took me 2 hours too) And fitting PU bushings is a breeze.
So what those prof. mechanics were mumbling about.. I dont know

[tomscott]

Still I'm sure 18 YO components are difficult to get out!

Labour does sounds expensive

[GuidoK]

Still I'm sure 18 YO components are difficult to get out!

It really depends on the state of your car and the competence (and tools that he uses) of the mechanic.
A pressed in bushing always requires some expertise and quality tools. Old car or new car.

Like I said, if you really put your shoulders into it, you can do it in a day. But you must have a carlift, and a bush extracting set and some other tools (transmission jack etc). A professonal mechanic should be able to.
Obviously paying for labour is always expensive, but one could always rent a car lift at a diy garage. Even if it takes 2 day's, thats probably about £200 or so.
What can take up time is for example an exaust that doesnt want to come off, but thats also a matter of in what state the car is.

[Darkangelv2]

Still I'm sure 18 YO components are difficult to get out!

Labour does sounds expensive

Roundozo and I were discussing this - possibly easier to pick up a used rear subframe, give it a paint and start fitting bushes off the car?

Then swap in.

As per video, I'm expecting no great shakes on the front end. With the rear I'm currently only looking at doing RTabs and roll bar (polybushes) at the moment on due to fear of difficulties with the rest of the subframe.

That said, is it worth adding away bar links? https://www.ebay.co.uk/itm/251742171970

[Darkangelv2]

Still I'm sure 18 YO components are difficult to get out!

It really depends on the state of your car and the competence (and tools that he uses) of the mechanic.
A pressed in bushing always requires some expertise and quality tools. Old car or new car.

Like I said, if you really put your shoulders into it, you can do it in a day. But you must have a carlift, and a bush extracting set and some other tools (transmission jack etc). A professonal mechanic should be able to.
Obviously paying for labour is always expensive, but one could always rent a car lift at a diy garage. Even if it takes 2 day's, thats probably about £200 or so.
What can take up time is for example an exaust that doesnt want to come off, but thats also a matter of in what state the car is.

I've been quoted £600 by 2 different BMW indies and that didn't include complete rear bush replacement or alignment.

As I said above, looking to do it myself as I'm pretty competent and prefer to spend the money on the tools.

[mr wilks]

Age + mileage doesn't always dictate that a Z will need suspension overhaul though , in my experience its not something that you can say at XXXX yrs or xxxx miles it will need switching out the Stratus grey Si roady i had last year on 85k 11 yrs old was a dream to drive even on 19s also a few weeks back i took a forum guys 2007 3.0Si out approx 65k & that too just soaked up the bumps + twists that it would worry me switching stuff out & spoiling whats already a good car
Meddling when its not needed can easily produce a poorer outcome

[GuidoK]

Roundozo and I were discussing this - possibly easier to pick up a used rear subframe, give it a paint and start fitting bushes off the car?

Then swap in.

This is certainly a good idea.

I also painted all the suspension arms, beadblasted all the aluminium parts etc, and that took far far more time than swapping out the bushings.
Getting the axle from underneath the car and removing all the bushings took me a long evening. Painting and doing up all the parts took me a week

Before (in all honesty, it was still in relative good nick if I see some of the more rusted UK parts due to the poor weather...)


After:


Mind you, if you take another back axle to do up, you're stuck with the condition of some parts like diff/driveshafts (obviously you can swap those out, but painting them etc takes time), and the brake rotor rear plates. You cant remove them without removing the rotor hub (which requires fitting new bearings), or you have to modify those plates.

Here I have a spreadsheet with most of the possibilities of polybushing your car:
https://audio.home.xs4all.nl/zooi/z4/bussen/xls/

If you do something like this I can only recommend 1 thing: get a generic bush pressing kit like this:
http://www.ebay.co.uk/itm/New-Bearing-S ... 1820250531
You'll still might need some sockets and rings for a few of the harder to reach bushings, but it makes things so easy.

The only bushings where I applied some heat was on the subframe bushings. I didnt burn them out, but just to loosen them up slightly (warm rubber is more plyable), because its difficult to get a good fit on them with the cups supplied in the kit above.

That said, is it worth adding away bar links? https://www.ebay.co.uk/itm/251742171970

My experience is that the rubber of the stock links is a pretty tight fit on the swaybar ends. Getting it out and swapping these in might be a pain.

[Darkangelv2]

Roundozo and I were discussing this - possibly easier to pick up a used rear subframe, give it a paint and start fitting bushes off the car?

Then swap in.

This is certainly a good idea.

I also painted all the suspension arms, beadblasted all the aluminium parts etc, and that took far far more time than swapping out the bushings.
Getting the axle from underneath the car and removing all the bushings took me a long evening. Painting and doing up all the parts took me a week

Mind you, if you take another back axle to do up, you're stuck with the condition of some parts like diff/driveshafts (obviously you can swap those out, but painting them etc takes time), and the brake rotor rear plates. You cant remove them without removing the rotor hub (which requires fitting new bearings), or you have to modify those plates.

Here I have a spreadsheet with most of the possibilities of polybushing your car:
https://audio.home.xs4all.nl/zooi/z4/bussen/xls/

If you do something like this I can only recommend 1 thing: get a generic bush pressing kit like this:
http://www.ebay.co.uk/itm/New-Bearing-S ... 1820250531
You'll still might need some sockets and rings for a few of the harder to reach bushings, but it makes things so easy.

The only bushings where I applied some heat was on the subframe bushings. I didnt burn them out, but just to loosen them up slightly (warm rubber is more plyable), because its difficult to get a good fit on them with the cups supplied in the kit above.

That said, is it worth adding away bar links? https://www.ebay.co.uk/itm/251742171970

My experience is that the rubber of the stock links is a pretty tight fit on the swaybar ends. Getting it out and swapping these in might be a pain.

Thanks for all that Guido. Looks like a fantastic job you did.

It appears that space, time and tools would limit me to just updating the 'accessible' bushes in that case.

[Leesfarm07]

Have to concur. Recently did ALL of the rear bushes on mine, and then had an alignment done... Transformation is an understatement...

Mike

So what does the newly bushed car feel like Mike?

[Ducklakeview]

Have to concur. Recently did ALL of the rear bushes on mine, and then had an alignment done... Transformation is an understatement...

Mike

So what does the newly bushed car feel like Mike?

A revelation.. Planted and precise now

Mike

[Leesfarm07]

Have to concur. Recently did ALL of the rear bushes on mine, and then had an alignment done... Transformation is an understatement...

Mike

So what does the newly bushed car feel like Mike?

A revelation.. Planted and precise now

Mike

Did you OEM bush everything or go down the poly bush route?