Subframe refurb on my 06 Z4 M Roadster
- Thread starter Gazhyde
- Start date
Happy to, but of course the parts I'm listing are for a UK RHD model. Unsure if any differences for Canada. If circled in RED the obvious bits you are looking for. I've only included the PNs for the core subframe stuff, my spreadsheet is now growing with other bits and pieces that are mainly aftermarket like braided brake lines, caliper rebuild kits, oils and other sundries.grannyknot said:
For reference I started with realoem.com and found the relevant sections to identify what's needed. You end up going down a bit of a rabbit warren locating the PNs to order because some of those shown on realoem have been superseded by later PNs - you find this by clicking on each PN in turn for the latest.
Subframe: Z4 E85 Z4 M3.2 Rear axle carrier
Trailing arms and lower/upper wishbones: Z4 E85 Z4 M3.2 Rear axle support/wheel suspension
Description BMW PN Amount
RUBBER MOUNTING front left 33312283573 x1 (Subframe bush)
RUBBER MOUNTING front right 33312283574 x1 (Subframe bush)
RUBBER MOUNTING rear 33312283419 x2 (Subframe bush)
ARB bushes 31352229711 x2 (Anti rollbar bush)
Rubber mounting 33326770824 x2 (Lower Wishbone bush)
Rubber mounting 33321092247 x2 (Upper Wishbone bush)
Handbrake bowden cables 34416785397 x2 (Handbrake)
Drop links 33552283743 x2 (Drop links)
Rear trailing arm bushes 33326770817 x2 (RTAB)
Upper/Lower Ball joints 33306852895 x4 (Ball joints)
Diff front/back PowerFlex PFR5-4620/PFR5-4621
Sorry for the lack of formatting, forum doesn't seem to like tables...
Our philosophy is to replace everything with rubber bushes - either better than OEM, or OEM bushes.grannyknot said:
The reason for poly on the diff was that the twin ear bushes don't look to have separate part numbers, so you need to change the whole rear cover. PowerFlex make a kit which does all 3 bushes (2 rear and the front), so that decision was convenience really. I'm sure if I did more digging I may have found the part numbers, but time was pressing!
grannyknot
Member
Excellent, thank you.Gazhyde said:
camtwister
Member
This is a helpful and informative thread.
Day 4 update: Most of the day it was Trev and myself but we made great progress until Joycey turned up mid afternoon 
It's another "bitsa" day, just trying to make progress in to the huge collection of bits and parts. We still have some more bits to paint so we got Trev setup on the bench, first thing to paint was the diff.
Before we started on prepping it for paint we removed the 2 ear bushes, which pretty much fell out will minimal effort. If you look carefully you'll see the OEM bush cores are oval, so must allow for some lateral movement of the diff (remember that for later).
Definitely the correct call to replace these, they are mush.
Fitted the new PowerFlex Black bushes which are 3 piece, 2 poly sections pushed in from either side and a central aluminium core. The central core on these are circular, not oval. I'm keeping an open mind about these now they are fitted, will see how they go...
While I left Trev painting I quickly change the gearbox oil and then got on with the 4 x subframe bushes. The 2 rear are the same part number, but the fronts are two different part numbers. The reason for this is that one of the fronts has an oval core and the other circular. Not 100% on the reason for this other than to make lining up the subframe easier when removing/reinstalling at a vague guess.
For this procedure it really pays off taking photos as you take stuff apart, lots of photos. The bushes are all directional in one orientation and have triangles in the rubber. However the diagrams don't tell you what direction they need to face, so referring back to my iPhone library I could zoom in on a previous picture and see that the triangles point to the front and rear of the car. Always take photos.
Then it's a simple assembly of threaded rod and a large socket for the bush to pull through in to. The socket is essential as the bush protrudes through the subframe, and this allows full insertion! A nice coating of grease on the bush helps. Rinse and repeat 4 times.
Back to Trev, who quite frankly has outdone himself this time. It looks almost new, not bad for a 15 year old diff!
It's another "bitsa" day, just trying to make progress in to the huge collection of bits and parts. We still have some more bits to paint so we got Trev setup on the bench, first thing to paint was the diff.
Before we started on prepping it for paint we removed the 2 ear bushes, which pretty much fell out will minimal effort. If you look carefully you'll see the OEM bush cores are oval, so must allow for some lateral movement of the diff (remember that for later).
Definitely the correct call to replace these, they are mush.
Fitted the new PowerFlex Black bushes which are 3 piece, 2 poly sections pushed in from either side and a central aluminium core. The central core on these are circular, not oval. I'm keeping an open mind about these now they are fitted, will see how they go...
While I left Trev painting I quickly change the gearbox oil and then got on with the 4 x subframe bushes. The 2 rear are the same part number, but the fronts are two different part numbers. The reason for this is that one of the fronts has an oval core and the other circular. Not 100% on the reason for this other than to make lining up the subframe easier when removing/reinstalling at a vague guess.
For this procedure it really pays off taking photos as you take stuff apart, lots of photos. The bushes are all directional in one orientation and have triangles in the rubber. However the diagrams don't tell you what direction they need to face, so referring back to my iPhone library I could zoom in on a previous picture and see that the triangles point to the front and rear of the car. Always take photos.
Then it's a simple assembly of threaded rod and a large socket for the bush to pull through in to. The socket is essential as the bush protrudes through the subframe, and this allows full insertion! A nice coating of grease on the bush helps. Rinse and repeat 4 times.
Back to Trev, who quite frankly has outdone himself this time. It looks almost new, not bad for a 15 year old diff!
Cont. from previous post...
aaaand, back to the bushes... This time the rear trailing arm bushes. We actually have a Z4 trailing arm bush removal tool, which includes a metal insert for pulling bushes in again. Again a thick coating of grease and simple threaded rod setup and ease them in.
Each trailing arm has a top and bottom ball joint, again pretty similar puller setup but using 2 large sockets on either end. No specific pics of that, just and after shot showing them at the top and bottom. You'll also notice that we pushed the new Meyle HD wheel bearings in as well.
This is a complete trailing arm, next stage will be to fit the hub and build the brakes on to it.
There are still more bushes to go, but the supervisor arrived home and got stuck in as well.
Lower camber arm bushes.
Upper wishbone bushes:
Final job for the day is to remove the wheel bearing race from the hub face. This happens on every rebuild, Z3 or Z4 when you pull the hubs. There are a couple of ways to do this, and we found it easier to cut the race this time around. Think this is how we will do Z4's in the future, it's just quicker than heating and beating on it with a chisel.
aaaand, back to the bushes... This time the rear trailing arm bushes. We actually have a Z4 trailing arm bush removal tool, which includes a metal insert for pulling bushes in again. Again a thick coating of grease and simple threaded rod setup and ease them in.
Each trailing arm has a top and bottom ball joint, again pretty similar puller setup but using 2 large sockets on either end. No specific pics of that, just and after shot showing them at the top and bottom. You'll also notice that we pushed the new Meyle HD wheel bearings in as well.
This is a complete trailing arm, next stage will be to fit the hub and build the brakes on to it.
There are still more bushes to go, but the supervisor arrived home and got stuck in as well.
Lower camber arm bushes.
Upper wishbone bushes:
Final job for the day is to remove the wheel bearing race from the hub face. This happens on every rebuild, Z3 or Z4 when you pull the hubs. There are a couple of ways to do this, and we found it easier to cut the race this time around. Think this is how we will do Z4's in the future, it's just quicker than heating and beating on it with a chisel.
North Yorkshire
Thanks John and Lynchey, another day in the 'shed.
Honestly I'm knackered after two full days of working on the car, so I'm going to cheat for now and just post a link to todays post on my full build thread. Just spent an hour since I've got home sorting pics and writing stuff up, and I don't have the energy to replicated here. I have an appointment with the shower, grab another coffee and count some sheep through my eyelids in my fave chair for a while
Enjoy it gents, we are having a rare Sunday shift tomorrow to get it down on the wheels and go for a test drive. Obviously will need a full geometry carried out on it, but should be good for a test drive. Will try and bring this thread inline with the main build thread tomorrow along with a Day 6 update.
https://zroadster.org/threads/2006-e85-z4-m-roadster-rear-sub-frame-rebuild.48939/post-709347
Honestly I'm knackered after two full days of working on the car, so I'm going to cheat for now and just post a link to todays post on my full build thread. Just spent an hour since I've got home sorting pics and writing stuff up, and I don't have the energy to replicated here. I have an appointment with the shower, grab another coffee and count some sheep through my eyelids in my fave chair for a while
Enjoy it gents, we are having a rare Sunday shift tomorrow to get it down on the wheels and go for a test drive. Obviously will need a full geometry carried out on it, but should be good for a test drive. Will try and bring this thread inline with the main build thread tomorrow along with a Day 6 update.
https://zroadster.org/threads/2006-e85-z4-m-roadster-rear-sub-frame-rebuild.48939/post-709347
Day 6 - Reassembling everything else and the finishing touches....
There isn't a huge amount to the final reassembly day, mainly because it was busy and the majority of it was fairly dull like refitting the exhaust and the large amount of undertrays.
There were a couple of jobs which weren't really related to this which I've detailed on my main progress thread elsewhere.
- S54 Chain Tensioner leak
- Braided clutch line / clutch delay valve removal
What we do have is some nice pics of the shinier stuff that people like, so lets kick off with some brakes!
EBC Yellow Stuff and HEL braided brake lines are our combination of choice - expensive but entirely worth it. There are 6 lines in total for the Z4M, 4 rear and 2 front. £150 for the lines and £80 for the pads.
Brand spanking new BMW OEM 328mm rear discs. These are the same as fitted to the E46 M3 and 12mm bigger than the Z3M front discs. Pleasantly affordable at £215 a pair delivered from a BMW dealer through eBay. You can see the HEL braided lines joining the hard lines in the upper left. The discs have had a light spray coating of lacquer to make them easier to clear later on.
Calipers look ace with a fresh coat of paint. If you look closely at this picture you may see a slight issue we rectified later in the day!
Front brake tidy up as everything looks good up front except for changing the brake lines.
Trev gave the front discs a good clean up and coat of silver Hammerite. Refitted the calipers. You can see that the exhaust mid sections have been refitted as you can see the cats hanging in the background.
Checking wheel nut torque after first test drive up the top of the road and back. You can see the laquer overspray is starting to be scuffed off by the pads.
and that's it for the technical side of the rebuild - she's finished!
I've driven maybe 25 miles since wheels down, a couple of shield rattles but no major clangs or clunks! Need to get it booked in for a full 4 wheel geometry this week before I get a full understanding of how she drives.
Will be doing a couple more posts over the coming weeks where I'll be talking about how much more awesome it drives (it does even with iffy geometry), and cover some of the parts costs and how much labour we put in to this build.
There isn't a huge amount to the final reassembly day, mainly because it was busy and the majority of it was fairly dull like refitting the exhaust and the large amount of undertrays.
There were a couple of jobs which weren't really related to this which I've detailed on my main progress thread elsewhere.
- S54 Chain Tensioner leak
- Braided clutch line / clutch delay valve removal
What we do have is some nice pics of the shinier stuff that people like, so lets kick off with some brakes!
EBC Yellow Stuff and HEL braided brake lines are our combination of choice - expensive but entirely worth it. There are 6 lines in total for the Z4M, 4 rear and 2 front. £150 for the lines and £80 for the pads.
Brand spanking new BMW OEM 328mm rear discs. These are the same as fitted to the E46 M3 and 12mm bigger than the Z3M front discs. Pleasantly affordable at £215 a pair delivered from a BMW dealer through eBay. You can see the HEL braided lines joining the hard lines in the upper left. The discs have had a light spray coating of lacquer to make them easier to clear later on.
Calipers look ace with a fresh coat of paint. If you look closely at this picture you may see a slight issue we rectified later in the day!
Front brake tidy up as everything looks good up front except for changing the brake lines.
Trev gave the front discs a good clean up and coat of silver Hammerite. Refitted the calipers. You can see that the exhaust mid sections have been refitted as you can see the cats hanging in the background.
Checking wheel nut torque after first test drive up the top of the road and back. You can see the laquer overspray is starting to be scuffed off by the pads.
and that's it for the technical side of the rebuild - she's finished!
I've driven maybe 25 miles since wheels down, a couple of shield rattles but no major clangs or clunks! Need to get it booked in for a full 4 wheel geometry this week before I get a full understanding of how she drives.
Will be doing a couple more posts over the coming weeks where I'll be talking about how much more awesome it drives (it does even with iffy geometry), and cover some of the parts costs and how much labour we put in to this build.
grannyknot
Member
Interested to hear what you have to say on how the new bushings feel, did you notice any visual signs of wear or fatigue on the original bushing you removed?
Also, do you off hand if the Hammerlite paint has a similar chemistry as the POR15 paints?
Thanks
Also, do you off hand if the Hammerlite paint has a similar chemistry as the POR15 paints?
Thanks
Majority of them had failed either visibly or pretty much fell out when removed, particularly the rear trailing arm bushes which had failed both sides. Will see if I can find some more pics to post, but you can see some in the first few updates on this thread.grannyknot said:
As for the Hammerite question, no idea!
It's worth adding some very specific details, we both really need to sit down and compile them all, for example before refitting the diff you need to install both passenger side arms to the subframe, this is because the diff is not central and clashes with the bolts.
Cheers, I like doing the write ups almost as much as the spannering!patriot66 said:Brilliant thread ! Excellent work, great info and great photos. This will be my project possibly autumn next year, so this will come in handy for reference
Think I took something like 170 picture in total, will likely put them somewhere and post a link to all of them in case the ones that didn’t make the thread are useful.