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Creaking suspension
blueskate - 25/7/11 at 12:11 PM

Hi All,

I've had creaky suspension on my MK since i got it on the road. I've traced the issue to the poly wishbone bushes but can't see a way of resolving the problem. Any ideas?

rallyingden - 25/7/11 at 12:15 PM

Ear Plugs !!

Sorry

RD

mookaloid - 25/7/11 at 12:16 PM

strip them down and lubricate with silicone grease

Edited to add Castrol Red Rubber Grease Brake Caliper Rebuilds 100 g | eBay

[Edited on 25/7/11 by mookaloid]

indykid - 25/7/11 at 12:16 PM

quote:
Originally posted by mookaloid
strip them down and lubricate with silicone grease

Annually

ETA - I stripped all my rear ones last year and fully greased them, but they're creaking again this year.

[Edited on 25/7/11 by indykid]

mookaloid - 25/7/11 at 12:19 PM

I have often wondered about fitting grease nipples to the bones for this but it worries me that it might weaken them too much...

ReMan - 25/7/11 at 12:21 PM

There's a few threads on this already
Serach for Grease + Bush

IMO you need to use moly type greasy grease not silicone or copperslip it dries out

blueskate - 25/7/11 at 12:29 PM

cool cheers, doing a search now for Greasy bush....

Bluemoon - 25/7/11 at 01:23 PM

Could be gone sometime then.. It may also be an idea to think about replacing the crush tubes with stainless steel ones, I intend to do this one day but need a source of suitable tube..
Dan

Bumble - 25/7/11 at 02:03 PM

I had exactly the same issue last week which I only noticed now that it's passed the IVA and on the road. On bumpy surfaces it was a nightmare. Couldn't face stripping it down having only just passed so tried some spray silicone on all the bushes........covered them in fact and let them soak then wiped up the excess and repeated. Cured the squeaks & creaks instantly.......how long it will last is anyones guess but at least I can put off the strip down and save it for a winter upgrade.
HTH,
Matt

Frosty - 25/7/11 at 02:16 PM

The problem is that the poly section is too big for the crush tube. Having seen issues like this come up a lot, I wrote a guide to bushes the other day.

Have a read here for more info: http://boardroom.wscc.co.uk/cgi-bin/ikonboard.cgi?act=ST;f=12;t=91297

Basically the bushes do not fit properly. Either the crush tube is shorter than the bush, or the crush tube does not fit in the bush properly.

The only solution is to take each one off the car, check it, and modify it so:

1) The poly bush fits in the wishbone perfectly (not too loose, not too tight)

2) The crush tube fits in the fitted poly bush perfectly.

3) The crush tube is fractionally longer than the bush (by no more than 0.25mm total.

You could take a whole weekend addressing it, but you'll never need to touch them again once they are right.

You'll be amazed at how well your car rides the bumps afterwards.

The only problem is finding out if the poly bushes are the ones which are designed to work by the poly twisting, or rotating around the crush tube. One of the many reasons why I don't like poly bushes.

Bluemoon - 25/7/11 at 02:37 PM

quote:
Originally posted by Frosty
The problem is that the poly section is too big for the crush tube. Having seen issues like this come up a lot, I wrote a guide to bushes the other day.

Have a read here for more info: http://boardroom.wscc.co.uk/cgi-bin/ikonboard.cgi?act=ST;f=12;t=91297

Basically the bushes do not fit properly. Either the crush tube is shorter than the bush, or the crush tube does not fit in the bush properly.

The only solution is to take each one off the car, check it, and modify it so:

1) The poly bush fits in the wishbone perfectly (not too loose, not too tight)

2) The crush tube fits in the fitted poly bush perfectly.

3) The crush tube is fractionally longer than the bush (by no more than 0.25mm total.

You could take a whole weekend addressing it, but you'll never need to touch them again once they are right.

You'll be amazed at how well your car rides the bumps afterwards.

The only problem is finding out if the poly bushes are the ones which are designed to work by the poly twisting, or rotating around the crush tube. One of the many reasons why I don't like poly bushes.


Nice post; But any ideas of how to find out what the bushes supplied by MK are, twisting type or rotating?

MikeRJ - 25/7/11 at 02:40 PM

quote:
Originally posted by Frosty
The only problem is finding out if the poly bushes are the ones which are designed to work by the poly twisting, or rotating around the crush tube. One of the many reasons why I don't like poly bushes.


All the poly-bushes I have seen have to have some motion between the crush tube and the bush. If they were design to work purely through bush deformation, then the crush tube would need to be bonded to the bush (or moulded in), like a metalastic bush.

Frosty - 25/7/11 at 03:04 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by Frosty
The only problem is finding out if the poly bushes are the ones which are designed to work by the poly twisting, or rotating around the crush tube. One of the many reasons why I don't like poly bushes.


All the poly-bushes I have seen have to have some motion between the crush tube and the bush. If they were design to work purely through bush deformation, then the crush tube would need to be bonded to the bush (or moulded in), like a metalastic bush.

Indeed, yet the fitting instructions for most specify that you must torque them up on the floor, indicating that the bush deforms a little too.

If they were a true rotating type, you could torque them up in the air. In my experience, they seem to work a bit by rotation, and a bit by deformation. How much of each depends on how well (or badly) each one fits into its wishbone housing. The end result is that every corner has a different rate until this is addressed, and this is my major gripe with poly bushes.

whitestu - 25/7/11 at 03:11 PM

quote:

The problem is that the poly section is too big for the crush tube. Having seen issues like this come up a lot, I wrote a guide to bushes the other day.

Have a read here for more info: http://boardroom.wscc.co.uk/cgi-bin/ikonboard.cgi?act=ST;f=12;t=91297

Basically the bushes do not fit properly. Either the crush tube is shorter than the bush, or the crush tube does not fit in the bush properly.

The only solution is to take each one off the car, check it, and modify it so:

1) The poly bush fits in the wishbone perfectly (not too loose, not too tight)

2) The crush tube fits in the fitted poly bush perfectly.

3) The crush tube is fractionally longer than the bush (by no more than 0.25mm total.

You could take a whole weekend addressing it, but you'll never need to touch them again once they are right.

You'll be amazed at how well your car rides the bumps afterwards.

The only problem is finding out if the poly bushes are the ones which are designed to work by the poly twisting, or rotating around the crush tube. One of the many reasons why I don't like poly bushes.


From my experience of my Indy the only part of that which applies is that the bushes are tight on the crush tubes and they push any grease off the tubes when you assemble them.

I took mine apart to check bush length and it was a complete waste of time as they were all spot on.

All my wishbones move very freely by hand with the springs off, but still creak if they arenīt lubricated regularly.

I just spray some chain lube on them every so often.

Stu

wicket - 25/7/11 at 03:21 PM

Creaked like mad when 1st on the road, used moly grease and been on the road 5 years and no creaky suspension.

Davegtst - 25/7/11 at 04:23 PM

Although mine isn't on the road yet i did have a few problems with it creaking and the suspension being extremly tight. It took me ages to press the bushes and crush tubes into the wishbones which Mk assured me was normal. About a month ago i took it all apart again as i wasn't happy with it. When i took the bushes out there is a ridge of metal inside the wishbone about 1mm high. I ground all these ridges flat and polished the insides of the wishbones with a dremel to get rid of the pwdercoating overspray. It was so much easier to reassemble it and now the suspension is much more free with no noise at all.

[Edited on 25/7/11 by Davegtst]

mad-butcher - 25/7/11 at 06:48 PM

I ground all these ridges flat and polished the insides of the wishbones with a dremel
If I've read this right you've ground the weld off the inside of the tube

tony

RichardK - 25/7/11 at 07:17 PM

quote:
Originally posted by Davegtst
When i took the bushes out there is a ridge of metal inside the wishbone about 1mm high. I ground all these ridges flat and polished the insides of the wishbones with a dremel to get rid of the pwdercoating overspray. It was so much easier to reassemble it and now the suspension is much more free with no noise at all.

[Edited on 25/7/11 by Davegtst]


I hope you didn't mean you used erw tube for the bush tubes, if you did I hope that the weld bit was in the middle of the bone arm with weld either side if that makes sense.

Hope I haven't worried you but I would take a look at them mate and replace if in doubt.

Cheers

Rich

mad-butcher - 25/7/11 at 07:46 PM

I must admit I've sent Dave a u2u as having seen posts and horrific photos of were the tubes have split I'm extremely concerned about the possible weakening

Tony