Polybushes

[JDUB]

I have just refurbed the rear beam on the Rocco (MK2 1.8 GTS) everything has been refinished or replaced and the last part to fit before I refit it to the car is the pivot bushes VW Part no. 171 501 537. These aren't available from VW or Heritage anymore so I have been reluctantly thinking about using Polybushes. I'm confused though about how they could ever work properly - This is my thinking :

I am happy to use Poly bushes on the ARB as they work in exactly the same way as the original bushes i.e. by "squashing" with a negligible rotational movement.

The bushes on the pivots however rotate mostly with a bit of "squashing" too. The original OEM rubber bushes are bonded to a steel sleeve and into a larger steel sleeve, both sleeves are clamped tight and the rotation is achieved within the flexibility of the rubber. Nothing moves against anything else, no wearing surfaces, no lubrication. The movement is all as a result of the torsional quality of the rubber, all good. The only downside is that eventually, after many years, they perish.

But as far as I can find out, Poly bushes in this application are not bonded to the inner or outer sleeves and therefore must rely on rotation to work ? Either in the outer sleeve, around the inner sleve, or both ? They assemble with grease but even so surely something is going to be wearing against something else and, surely they will stick before they break free and move even when they are new ?

I researched on the internet and came up with this http://www.netbug.net/blogmichael/?p=103 which seems to make perfect sense.
Is this wrong ? Can anyone explain how a polybush would operate properly in this application ?

[JDUB]

I'm going to fit some pattern rubber inserts which replace the rubber in the original VW housing. They have a bonded steel tube inside and once assembled should operate like the OEM setup. I sourced them from Ebay a while ago but, It's taken me a long time to get around to fitting them so I was revisiting the polybush option before I used them, posted a link some time ago but can repost if anyone's intetested after reading about poly bushes ?

[Nate]

I'm not a fan of polybushes. I fitted them to the front of my mk2, and they destroyed what little ride comfort there was. They lasted nearly 2 weeks before they were in the skip.

That said, I have just found myself in the same situation as you. Rear beam shotblasted and painted, with all new brakes, shocks and springs going on. Although the rubber is fine, the metal brackets are neeeding some love, and given that poly bushes have only set me back a tenner, I'll give them a try. I am expecting to be disappointed, but we'll see. In the meantime, I am looking out for sensibly priced rubber ones!

[beekeeper]

been fitting these for years.

yes, they can make the back end twitchy but i wouldn't say excessively hard.

[Mr Funk]

I'm not a fan of polybushes. I fitted them to the front of my mk2, and they destroyed what little ride comfort there was. They lasted nearly 2 weeks before they were in the skip.

That said, I have just found myself in the same situation as you. Rear beam shotblasted and painted, with all new brakes, shocks and springs going on. Although the rubber is fine, the metal brackets are neeeding some love, and given that poly bushes have only set me back a tenner, I'll give them a try. I am expecting to be disappointed, but we'll see. In the meantime, I am looking out for sensibly priced rubber ones!

I use them all apart from the engine. It's slightly firer but the Weitecs take care of that. Next time you're down I'll make sure the Bandit is out. Giggidy

[mark1gls]

Can't notice any differnance between rubber or polybushes on the rear beam on my Mk1 but I don't really drive it near the limit.