Powerflex bushings - fitting

[Ferret]

Okay, the heavens opened so I've only got one side done, and by god was it a bitch of a job!

Found that you can just about wind the old bushing out with a three-leg puller and a bit of luck...
http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00035.jpg

Yes, it's pissing it down
http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00038.jpg

It takes all of 5 minutes to get the new bushing fitted after the small 4 hour war of getting the old one out...
http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00041.jpg

http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00042.jpg

[Ferret]

Amazingly, the left side of the car is no longer sagging after fitting this bushing! The car now has an imbalance between left and right with the left wheel sitting in the arch like it was designed to... I noticed when lifting the car the core of the old bushing was moving freely up and down inside the rubber of the bushing - I wonder if this is why E34 rear suspension sags so badly as it ages?
http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00044.jpg

[e34.535i.sport]

Looking good mate!

You've got me tempted with them, how much and were did you source them?! You'll have to give a reveiw once they're both in!!!

[Ferret]

Looking good mate!

You've got me tempted with them, how much and were did you source them?! You'll have to give a reveiw once they're both in!!!

They're about 25 quid a pair [EDIT: I meant side!] mate!

They're soooo easy to put back in after you've just battled the old bushings out - it was a total 'WTF!?' moment :D

Something that's been nagging me though - I couldnt saw through the rubber using either a metal blade or a wood blade - am I just not trying hard enough or something?

[e34.535i.sport]

They're about 25 quid a pair [EDIT: I meant side!] mate!

They're soooo easy to put back in after you've just battled the old bushings out - it was a total 'WTF!?' moment :D

Something that's been nagging me though - I couldnt saw through the rubber using either a metal blade or a wood blade - am I just not trying hard enough or something?

Hey thanks for the info!

I used a jigsaw and had trouble for a long time until I just said **** it and went nuts on it. At first I was worried about cutting too far, but once I decided to go hard at it it wasn't too long before it was out! Putting some oil on the blade was the way forward too as it helps the blade move through the rubber... Oh and I used metal blades I think!

[e34.535i.sport]

Good job mate, I think this is on the cards for me as well, it books as a 5 hour job at a garage apparently. Did you have to get the car on axle stands or can you use ramps?

Axel stands are sound for this job, do one side at a time... Have a look at this it may come in handy:

http://www.bimmer.info/forum/showthread.php?t=35718

[BigKriss]

The bush sits flush with the subframe plate below. Is this correct?

http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00044.jpg

[Ferret]

According to other treads it's rather tough to fit in new subframe bushing (special lubricant recommanded and must put the bushing in the freezer couples of hours before doing the job...). If it was that easy, is it to say that the subframe assembly may easily play along your new bushing and possibly knock the bottom plate / rod ? The bushing seems to have kind of shoulder on subframe top but it's not the case at the bottom end, so if the bushing is not real stiff in the frame don't you think you may experience a play there (handling compromise and possible clink noise)?

The bushings have shoulders at the TOP and BOTTOM - they do not require a friction fit to keep the subframe in place!
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/DSC00025.jpg

Unlike the genuine subframe parts that only have a shoulder at the bottom:
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/7036_1.jpg

With the double shoulder above, super tight friction is not necessary as the subframe is effectively locked from moving up or down.

[Ferret]

Are they Poly bushings? Also where did you get them from?

Yeah, they're slightly rubberised poly bushings - just rubberised enough to not transmit diff noise etc!

Got them from ebay - manufacturer http://www.powerflex.co.uk

You should be able to get them all over the world, but I may consider exporting some for people that cant find them...

[Ferret]

The bush sits flush with the subframe plate below. Is this correct?

Yeah mate, top and bottom the bush is profiled such that it takes the maximum slack out of the system - the shoulders at the top and bottom are under slight compression when the whole lot's bolted together.

There's literally nowhere for the subframe to go - it cant flex up and down like with the old genuine bushing.

[Ferret]

Good job mate, I think this is on the cards for me as well, it books as a 5 hour job at a garage apparently. Did you have to get the car on axle stands or can you use ramps?

I cheated and used two jacks - you dont have to work with the wheels off and you most certainly dont have to work in a position where the car will fall on you!

Remove the subframe plate with all four wheels on the deck, or at least loosen all three bolts off - if you cant get the subframe bolt to shift, cheat again and put a trolley jack under it, lift the back end of the car a cm with it and bounce the back end - it'll come out like a bullet from a gun so be careful.

I found the best way to get the bushing out was to carefully insert 2 legs of a puller up through the gaps of the bushing, turn inwards and build the puller up with the puller bolt going through the centre of the bushing. Then carefully lower the subframe, place a lump hammer or equivalent solid object over the top of the bushing - lift the subframe until the hammer contacts the body work and start winding the puller out.

Once the bushing moves 2-3mm you're safe, undo everything, convert to a 3 leg puller and repeat the above, except place the puller legs carefully around the outside lip of the bushing...

btw, once you've got the subframe plate off, you can happily jack the car up on a trolley jack with a pad straight onto the plate where the two 13mm bolts attach - it's a reinforced plate!

[leicesterboy15]

Good job mate, I think this is on the cards for me as well, it books as a 5 hour job at a garage apparently. Did you have to get the car on axle stands or can you use ramps?

[Ferret]

Those shoulders look like the dimentions that Bruno's spacers are trying to tighten up. Don't know Bruno's exact dimesions, but the look pretty close.

I was thinking that actually - I'll grab a measurement off them when I go out to get drowned, sorry, fit the other bushing later.

[healtoeit]

They're about 25 quid a pair [EDIT: I meant side!] mate!

Are they Poly bushings? Also where did you get them from?

[Claude]

Amazingly, the left side of the car is no longer sagging after fitting this bushing! The car now has an imbalance between left and right with the left wheel sitting in the arch like it was designed to... I noticed when lifting the car the core of the old bushing was moving freely up and down inside the rubber of the bushing - I wonder if this is why E34 rear suspension sags so badly as it ages?
http://i11.photobucket.com/albums/a190/Ferret101/subframe/DSC00044.jpg

According to other treads it's rather tough to fit in new subframe bushing (special lubricant recommanded and must put the bushing in the freezer couples of hours before doing the job...). If it was that easy, is it to say that the subframe assembly may easily play along your new bushing and possibly knock the bottom plate / rod ? The bushing seems to have kind of shoulder on subframe top but it's not the case at the bottom end, so if the bushing is not real stiff in the frame don't you think you may experience a play there (handling compromise and possible clink noise)?

[sneekens]

Nice!! Btw, what do you mean by sagging? The rear wheels having a negative camber? Anyways, give us feedback on how it feels on the road! thanks!

[BigKriss]

nice work. with a jigasaw i found the subframe bush difficult to cut

[Sixdown]

Nice!! Btw, what do you mean by sagging? The rear wheels having a negative camber? Anyways, give us feedback on how it feels on the road! thanks!

Usually the driver's side is a little higher than the rest of the car to compensate for the driver. This is normal design, and if you don't have the minor difference, then the bushings and such can be quite worn down as far as I know.

I've never noticed any abnormal sagging with age.

Whats the easiest way to cut out the bushing? I've tried to work on my old volvo's bushings and a normal hack saw didn't even work...

[MBXB]

http://www.tycksen.com/bmw/tech/subframe/index.php

[MBXB]

Those shoulders look like the dimentions that Bruno's spacers are trying to tighten up. Don't know Bruno's exact dimesions, but the look pretty close.




The bushings have shoulders at the TOP and BOTTOM - they do not require a friction fit to keep the subframe in place!
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/DSC00025.jpg

Unlike the genuine subframe parts that only have a shoulder at the bottom:
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/7036_1.jpg

With the double shoulder above, super tight friction is not necessary as the subframe is effectively locked from moving up or down.

[Ferret]

Oups ! i didn't realized that the bushing was build in two parts, now i understand !

If those bushings are that stiffer than the genuine (rubber) ones, is it to say that the ride will be harsher and they will do less noise isolation / filtering ? Are those side effects noticables ?

They split like this:
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/DSC00028.jpg

You dont really get any extra road noise with these... however they DO transmit slightly more 'vertical' noise apparently - though not an intrusive level (going over small bumps/rough surfaces)... I'll review em when I get the other one in... however it's looking like with this weather I'm not going to be able to get the other one fitted till next friday - I'm working away from the office most of next week!

[Ferret]

Nice, can you choose the durometer of the urethane or is there only one choice in stiffness?

Not 100% sure what you mean, but if you're referring to the stiffness - the 'standard' ones I got have just enough rubber-y-ness (I can hear my old English teacher yelling in my head for that one) that they're stiff, but will take most vibrations out!

I dont think you can choose these - they come as is!

For a couple of extra quid they threw in replacement anti-rollbar bushings too :)

[Claude]

The bushings have shoulders at the TOP and BOTTOM - they do not require a friction fit to keep the subframe in place!
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/DSC00025.jpg

Unlike the genuine subframe parts that only have a shoulder at the bottom:
http://i11.photobucket.com/albums/a190/Ferret101/Suspension/7036_1.jpg

With the double shoulder above, super tight friction is not necessary as the subframe is effectively locked from moving up or down.

So with those double shoulder with larger diameter than the place you have to insert it in the subframe, how can you insert it that easily ? If that powerflex material is that flexible to permet squizzing it in place what about it's durability ? What's the experience of others with the durability of those bushings ?

If it really does the job for long time, that's what i need, two years ago mine were change by a BMW dealer, i saw them do the job, the put the genuine ones, put a lot of grease to insert them... results few month later some knocking noise from behind and i suspect it's the subframe moving up and down on those bushing that causes the noise.

Were did you get those powerflex bushing ?

[BigKriss]

Nice, can you choose the durometer of the urethane or is there only one choice in stiffness?


Yeah mate, top and bottom the bush is profiled such that it takes the maximum slack out of the system - the shoulders at the top and bottom are under slight compression when the whole lot's bolted together.

There's literally nowhere for the subframe to go - it cant flex up and down like with the old genuine bushing.

[Sixdown]

So with those double shoulder with larger diameter than the place you have to insert it in the subframe, how can you insert it that easily ? If that powerflex material is that flexible to permet squizzing it in place what about it's durability?

The bushings are two part. In the image you can see the seam in between the top and bottom. These two parts slide over the metal insert which the bolt feeds through, compressing both ends together and giving it a tighter fit.
As far as i know, they last FAR longer than OEM bushings but are substantially stiffer.


EDIT: Just noticed this was already responded to...stupid post time disorder.

[Claude]

The bushings are two part. In the image you can see the seam in between the top and bottom. These two parts slide over the metal insert which the bolt feeds through, compressing both ends together and giving it a tighter fit.
As far as i know, they last FAR longer than OEM bushings but are substantially stiffer.


EDIT: Just noticed this was already responded to...stupid post time disorder.


Oups ! i didn't realized that the bushing was build in two parts, now i understand !

If those bushings are that stiffer than the genuine (rubber) ones, is it to say that the ride will be harsher and they will do less noise isolation / filtering ? Are those side effects noticables ?

[BigKriss]

I'll try to be more clear, you received the standard ones, is there a harder/softer version available?


Not 100% sure what you mean, but if you're referring to the stiffness - the 'standard' ones I got have just enough rubber-y-ness (I can hear my old English teacher yelling in my head for that one) that they're stiff, but will take most vibrations out!

I dont think you can choose these - they come as is!

For a couple of extra quid they threw in replacement anti-rollbar bushings too :)

[Ferret]

I'll try to be more clear, you received the standard ones, is there a harder/softer version available?

Nah sorry, as-is one-hardness-fits-all routine :)

Picked up some new dogbones today as well to go in... still effing raining though!

[saluki540i]

In response to the quality of Powerflex - they're top notch. I've installed them on my xr4ti. They should last just about forever.

[BigKriss]

ferret, how did these end up going?