E85 Rubber Bush Replacement Program

B

Boris

Member
 Durham
My new (to Me) Z4 2.2 Roadster was well looked after by its previous owners and only has 57,000 miles on it, but at the end of the day its 12 years old at least.

So in my thinking all the rubber suspension bushes must be starting to perish and the car can't be at its best if that's the case.

Does anyone have available a full list with locations of all the rubber bushes on the car (and ideally description and part numbers) I'm thinking of setting about over the winter and replacing them all, some I could do myself but others would be done by a local garage I have dealt with for years.

Cheers

Nev
 
jamie_z4 said:
here you go

https://www.powerflex.co.uk/road-series/products/Z4+E85+%26+E86+%282003-2009%29-1203/1.html
Click to expand...

Cheers,

so that's a grand total of £1788 just to buy the bushes :roll:
 
Can someone point out to me which would make the most difference to change, some of the others are going to have to wait!
 
yep! Doubt youll need them all changing. Biggest improvement is the RTAB's and the front lolipops. Others tend not to wear as quickly.
 
Rear Trailing Arm Bushes I know should be done and the lollipops but which bushes are the "lollipops"
 
Boris said:
Rear Trailing Arm Bushes I know should be done and the lollipops but which bushes are the "lollipops"
Click to expand...

Front Wishbone bushes :)

I would also do the wishbone whilst there as they are fairly cheap to replace. :)
 
jamie_z4 said:
yep! Doubt youll need them all changing. Biggest improvement is the RTAB's and the front lolipops. Others tend not to wear as quickly.
Click to expand...

These plus
-Front wishbones,
-Anti roll bar bushes
-Drop links

I would suggest as a starter, would go too mad on it, you would see a greater benefit in changing shocks to be fair though and a few of the main bushes :)
 
This is a spreadsheet I've made that highlights Poly possibilities from both powerflex and strongflex with some added notes on research

https://audio.home.xs4all.nl/zooi/z4/bussen/xls/
 
I wouldn't put poly on my Zed.. It's a firm enough ride as it is..

I replaced ALL of the bushes, front and rear with MEyleHD and Lemforder, plus RTAB limiters - Took me a day, and cost less than £105 all in..

Mike
 
Hi Neville,

There is a really good youtube video entitled "Polyurethane Suspension Bushes - The Good & Bad" , 27 minutes long but well worth watching. It shows some of the problems with using powerflex bushes and the advantages in using a properly engineered product, "super-pro bushes..

I tend to agree with Mike's comments and would either stick with Meyle HD or lemforder , or if looking for something extra investigate the use of super-pro bushes.

The limiter discs in the rear suspension mounting brackets would also be on my list of priorities plus renew shocks/springs.

Dave
 
Boris said:
Can someone point out to me which would make the most difference to change, some of the others are going to have to wait!
Click to expand...

As above, on mine the rear upper (balljoint) and lower eccentric bushes were badly worn (less than 60k miles) and this was affecting the ability to properly setup the geometry, as it would change under hand pressure on these points. The inner rears weren't too bad, but were definitely worn.

Mike
 
Peterboroughdave said:
Hi Neville,

There is a really good youtube video entitled "Polyurethane Suspension Bushes - The Good & Bad" , 27 minutes long but well worth watching. It shows some of the problems with using powerflex bushes and the advantages in using a properly engineered product, "super-pro bushes..

I tend to agree with Mike's comments and would either stick with Meyle HD or lemforder , or if looking for something extra investigate the use of super-pro bushes.

The limiter discs in the rear suspension mounting brackets would also be on my list of priorities plus renew shocks/springs.

Dave
Click to expand...


This one??

[youtube]_z6OEohnPKw[/youtube]

Mike
 
Peterboroughdave said:
Hi Neville,

There is a really good youtube video entitled "Polyurethane Suspension Bushes - The Good & Bad" , 27 minutes long but well worth watching. It shows some of the problems with using powerflex bushes and the advantages in using a properly engineered product, "super-pro bushes..
Click to expand...

Actually, let me nuance this a bit because if you apply this video on the z4 its just a bunch of 'fear mongering'
I'm probably one of the only people here who has personally polybushed a z4 for all bushings and has a few years of experience (5-7 years) driving it.
That video is about an MX5. All problems with bushings, or ANY part on a car are always part specific (so brand/model specific)
The problems highlighted in that video are probably real (although there is no real comparison there as we dont see a proper mounted powerflex bushign), but they only apply for that specific bushing for that specific car. If that specific bushing isnt applied in the z4, it wont have that specific problem.
That doenst mean that certain important design features are worth looking at. For instance that knurling which is talked about. For the z4, most powerflex and strongflex bushings also have that knurling. So thats absolutly not a superpro feature, powerflex has that too on most bushings. (and there are also superpro bushings without that knurling) That means that (in your words) powerflex makes a properly engineerd product. Also in that video we see an old bushing that how long god knows may have been in there. Both powerflex and superpro (and strongflex for that matter) continiously redevelop their products and you can see that in that their products for specific applications change over the years. As a matter of fact, if you'd now look up that very same bushing at powerflex that's talked about in that video, you'd see that their current product has a different design. For all we know the bushing in that video is a design sold back in the 90's. (looking back at everything in hindsight is always very easy but not representative)
I'm not trying to talk down superpro because I think they too make a very good product, but basing opinions on that video and transposing it on z4 products makes absolutely no sense at all from an engineering pov.
Usually the first product on the market is the worst one designwise.
 
GuidoK said:
Peterboroughdave said:
Hi Neville,

There is a really good youtube video entitled "Polyurethane Suspension Bushes - The Good & Bad" , 27 minutes long but well worth watching. It shows some of the problems with using powerflex bushes and the advantages in using a properly engineered product, "super-pro bushes..
Click to expand...

Actually, let me nuance this a bit because if you apply this video on the z4 its just a bunch of 'fear mongering'
I'm probably one of the only people here who has personally polybushed a z4 for all bushings and has a few years of experience (5-7 years) driving it.
That video is about an MX5. All problems with bushings, or ANY part on a car are always part specific (so brand/model specific)
The problems highlighted in that video are probably real (although there is no real comparison there as we dont see a proper mounted powerflex bushign), but they only apply for that specific bushing for that specific car. If that specific bushing isnt applied in the z4, it wont have that specific problem.
That doenst mean that certain important design features are worth looking at. For instance that knurling which is talked about. For the z4, most powerflex and strongflex bushings also have that knurling. So thats absolutly not a superpro feature, powerflex has that too on most bushings. (and there are also superpro bushings without that knurling) That means that (in your words) powerflex makes a properly engineerd product.
I'm not trying to talk down superpro because I think they too make a very good product, but basing opinions on that video and transposing it on z4 products makes absolutely no sense at all from an engineering pov.
Click to expand...


http://www.suspension.com/blog/rubber-v-polyurethane-suspension-bushings/ :fuelfire: :fuelfire:

:D

Mike
 
^sure most polyurethane will give more nvh but thats because they're mostly stiffer because they're a performance product.
A KW coilover kit is also stiffer than OEM but will also give more performance.
I have quite a few performance products on my car and seriously I cant name a single one that gave less NVH. But that comes with having a faster/better handling car, there's always a tradeoff. But the car in itself is also already a tradeoff. If you want a cumfy car, buy a mercedes S class (not suitable for enthousiastic driving on back roads or mountain roads though.....)

As for your article about the re-grease (4-5 years) I've inspected my fcab (powerflex) after 7 years (they have been the longest on my car) and they were still properly greased, so thats not a set rule (the bushing looked like new also). However what has been a fact is that the factory bushings in that spot DIDN'T last 7 years on my car, so in this instance the re-greasing period was longer than the lifespan of the OEM bushings. And thats quite a testimony to quality I think. (usually performance products dont have OEM lifespan because their main goal is performance gain, not lifespan)

Also indeed fitting them is easier, but If you can remove the old bushing it usually means you can also install an OEM bushing (because thats always easier). But it saves some time (although there are multiple poly bushings that also have to be pressed in; most bushings that have a orient critical mounting).

BTW OEM bushings can also squeak once they start to wear a bit. And not all OEM bushings are bonded. The OEM arb bushings for example. They have the same risc of squeaking (maybe even more) than polyurethane ones.
 
Dave/Mike,

Much appreciate the trouble you have gone to digging out that vid; a picture or vid in this case speaks a thousand words as they say.

I must admit I thought the poly bush was an interference fit on the crush tube and the crush tube rotated around the bolt, but now you see it in action it can't its crushed between the two flanges, simples.

:thumbsup:
 
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