polybushes

[procta]

where is the best place to buy a full blown poly bush kit for the 306? as my HDI has got a knock, so I suspect that one of the anti roll bar bushes has bit the dust.
what do you lads run?

[Stef205]

Oem bushes, polly bushes give more play imo. A decent oem bush will be far superior

[procta]

Oem bushes, polly bushes give more play imo. A decent oem bush will be far superior

i read about the engine mount one failing, which I am not too keen on the idea, Plus with this car been 14 years old I am wanting to look at replacing bushes, and want to make sure that this car continues to be flawless.

[Stef205]

engine mounts fine but not wishbone or any suspension units imo

[miles]

Std front wishbone and ARB are by far the best and Vibra Tech P bush's, none are Polly

[zx_volcane]

Running powerflex black series front and rear wishbone bushes here and no complaints. I do agree that genuine oem Peugeot bushes are going to be pretty fantastic.

Had a big bar in all the wishbones when the subframe was off recently, and could find zero play at all there.

I did weigh up running the vibratechnic p bushes with oem front wishbone bushes, but went the other way mostly due to the groupbuy that was organised here.

Not sure arb bushes are hugely prone to wearing out?

[Poodle]

I've had to do them on a few 306s now, wouldn't say it's a common problem though.

I find the powerflex black stuff a little harsh, really want vibratechnics kit but it's not cheap.

[RetroPug]

Bear in mind that polyurethane is cheaper than good quality rubber, OEMs would use it if it were as durable, and gave favourable characteristics. Absolutely minimal compliance in suspension components designed to be compliant by using a stiff material that doesn't flex very well is not necessarily ideal just because subjectively it feels good.

Good quality bushes like vibratechnics are expensive because they are good. Cheap polybushes are cheap because they're made of sub-optimal, cheap materials. Whether or not you like or dislike them personally, rubber is a superior material for bushes if it is good quality rubber with the desired characteristics.

With suspension components you get what you pay for.

[powerandtorque]

Bear in mind that polyurethane is cheaper than good quality rubber, OEMs would use it if it were as durable, and gave favourable characteristics.

In some rare instances they do - 205 GTi anti-roll bar bushes are poly as standard for example, and they last exceptionally well.

[Rippthrough]

Crap polyurethane is cheaper than good quality rubber....decent polyurethane isn't.

The reason OEM's don't use it for bonded bushes is the bond strength to the steel is lower than the rubber without an extra step of treatment so it ends up much more expensive, and they won't use them as aftermarket bushes are used (as bearings rather than bushes) because it means there's much more friction and wear in the suspension, so the ride/noise/handling all deteriorates compared to a flexing bush, which has almost no friction.
To make a rotating bush work you need all sorts of extra machining steps to ensure there's plenty of preload to keep full contact and increase the wear life, knurling to bring grease into the bearing area - otherwise the poly grabs the tube and you end up with massive wear and even in some cases, bent or broken arms (see mx5's and rx8's with cheap powerflex kits...), then you need a pair of lip seals either side to keep dirt and water out, and tapered ends with smooth stainless bearing surfaces on the chassis side to allow the flanges easy movement.
If your polybush is just a top hat shape and pushes in easily by hand, then it's probably 99% certain it's shit.

Basically you've just quadrupled the price of the bush in order to make it a bit stiffer. When an OEM can do that for the same price as before just by making the rubber one wider.

[RetroPug]

Made the point I was attempting to make a lot better than I did with some extra info that I didn't know. Thanks!

[welshpug]

Where a manufacturer makes its own high spec variant of a production vehicle, you'll find proper steel bearings, often still with some rubber around them.