#ZedShed 2006 E85 Z4 M Roadster rear sub frame rebuild

[beanie]

Great read and a considerable amount of work. Might have to leave mine with you guys at some point in the future as I don’t fancy taking all that on!

Do you get any extra nose from the diff bushes? I know some people complain when fitting poly in this area.

 

[Stevo7682]

So guys how did you find the z4 rear end to work on compared to the z3 obviously a lot more complex due to being multi link as opposed to semi trailing arm you have once again done a first class job and a great write up gives a great insight to anyone else considering this the time and cost involved to do this properly

Stephen.

 

[GazHyde]

Do you get any extra nose from the diff bushes?

Nothing perceptible in terms of increased noise, but then I have an exhaust more than capable of drowning out excess bush noises

So guys how did you find the z4 rear end to work on

We loved it soooo much we bought a rusty Z4 from Scotland to follow it up, then next in will be Lee's Coupe! There are just so many more parts involved even just stripping down undertrays, braces, plating just to get to the subframe. It's at least twice the work to do the same procedure at a rough estimate. There are advantages as I've mentioned already though, like plenty of shared components bringing down the prices as well as better availability generally.

That all said, the Z4's are starting to suffer as much as the Z3's in terms of degradation underneath so I guess expect more Z4 content!

 

[Stevo7682]

I suppose you have to look at the fact the early ones are now nearly 20 yrs old .
Depends where its been as well if you saw some of the things that I mot corrosion to components a big issue here even aluminium parts volvo and Ford and mazda cx range rear alloy shocks top mounts shatter.
Bushes will be aged and brittle on most older stuff these days rubber bits like that you can't fight time ( a nice dry warm garage will slow considerably) but outside our environment not car friendly.
Stephen.

 

[beanie]

Nothing perceptible in terms of increased noise, but then I have an exhaust more than capable of drowning out excess bush noises

It’s a good solution!

 

[CJK]

I found this article very interesting as I have rust issues on the rear axle components of my 2003Z4 2.5i SE. I do not have the garage facilities and tools required to carry it all out all though I am pretty capable of the work required. I thought you done an amazing job and the pictures and explanations were brilliant.
It has scared my a bit and I don’t know if I am prepared to take on a project like this.
Charlie

 

[GazHyde]

Thanks Charlie!

It's easy to be put off by a write up like this, honestly there were times when I was questioning my decisions. Except for some specific tools there's not much that can't be done with time and patience. Main thing is to not try and get it sorted in a weekend, take your time and prep as much before hand - then ask questions when you have them. Some of what we've done wasn't strictly necessary, you may be able to get at the bits you need to rust treat with it on axle stands at the back and with the subframe in place. Take off only what you need to get access to things.

We have a history of powder coating everything now more out of habit than a specific need. It sure makes it look nice underneath, but when I jacked the car up a week or so back the subframe is as covered in muck and dirt just as it was before we started

 

[CJK]

I am just starting the job now and my first step is to remove the two drive shafts to replace the ABS rings as I am getting warning lights on the dash. I have come up with a problem straight away maybe you could help me with. I measured the retaining nut on the wheel end and got a 12 point 30 mm socket from Halfords. When tried it I found it was a bit loose on the nut. So I ordered a 29 mm socket on eBay and it doesn’t seem to go on(too tight). Can you help me withe the correct size to use and where to buy it?
Thanks Charlie

 

[GazHyde]

Can you help me withe the correct size to use and where to buy it?

Can't remember off the top of my head but we have a box with a selection of large sockets we use. Maybe @Lee can remember off the top of his head, otherwise would have to wait till Saturday till I'm near the toolkits.

 

[Lee]

It is a sloppy fit due to it being a 12 point socket. If you can use a 6 sided you will get a snug reafirming fit.

Use the 30mm 12 sided and get your body weight behind it with a nugga gun.

 

[CJK]

It is a sloppy fit due to it being a 12 point socket. If you can use a 6 sided you will get a snug reafirming fit.

Use the 30mm 12 sided and get your body weight behind it with a nugga gun.

Thank you Lee. I understand it better now as I was trying to use the 12 point socket by hand using a breaker bar when it works with an impact wrench. I will get a 6 sided socket and try or get an impact wrench for the 12 point one.

 

[GazHyde]

I don’t often remove my exhaust system on a Friday morning, but when I do I take the opportunity to buff my tips! There will be an update on why I’ve taken the exhaust off in the near future.

Autosol applied like sun cream

Much better, although the chrome has tarnished to some extent.

 

[Bazza]

Oh shiny