Front Control arm bushes 1986 LHD Syncro T25

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syncro4us
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Front Control arm bushes 1986 LHD Syncro T25

Post by syncro4us »

I will be having to install some new old stock  VW bonded rubber  bushings (Bently page 40.16) into the front control arms for our syncro prior to installing them into the sub frame.
The bushes  are rubber bonded to an inner metal cylinder core tube through which the securing bolt runs. The core tube itself has one end that is machines/produced with flat rim and the other where the rim has three pips at 60 degrees to each other to presumably stand off and lock rotation of the bush at some point.
But  I am trying  to determine whether the flat end or the end with pips face forward
So far the consensus  from others seems to be that the end with the pips faces forward as this would be the thrust face when the vehicle is driven forward.Anyone else have any other views on this. 
It seems a small point but can anyone describe how exactly the rubber bushes work
1 If they are locked then as the suspension moves then presumably the rubber itself has to move building up potential torque whilst the core stays stationary.  
2 If the cores are allowed to freely move then the bolts should not be tightened to allow free rotation  but Bently page 40.26 shows the nut on the securing bolt to be tightened to 90Nm or 66ft lbs which would immobilise the central core or at least cause the pips on the core to scrape and perhaps erode the metal of the sub frame  over time or am I missing something?

Any one with further information can you let me know and thanks to those that have contributed so far.

Kevin

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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by syncroandy »

The bonded rubber suspension bushes twist as the suspension moves. The bolts through the sleeves should be tightened, but only once the suspension has been put into its normal resting position (eg. wheels on the ground). As regards orientation, I'm not sure it matters hugely, I just try to get them back in the same as the old ones came out.

Edited: Corrected typo.
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by silverbullet »

I now wish that I had fitted polybushes when I rebuilt my front suspension a few years ago. The supposed OEM rubbers have split, the radius rod ones have too (the nuts werent even tightened up!), even though the van has never been used since.
So that will all have to come off again.
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by syncroandy »

Ian, that is shocking. Did you complain to the supplier, what did they say ?

I've been lucky and so far have managed to use genuine for those bushes I've done, but for my kombi rear arms, I had to use aftermarket, so your experience is a concern. I still have a few genuine front arm bushes in stock, thankfully. So far I've been lucky with track rod bushes.

I'm not a fan of poly, so a source of good rubber bushes matters to me.
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by silverbullet »

BW are well aware of the problem with modern black rubber that comes from Lemförder.
We can, unfortunately, blame an EU directive that forced manufacturers to reduce the actual natural rubber and sulphur content of vulcanized rubber products on environmental impact grounds.
Trouble is that its resulted in a far shorter product lifespan and an increase in raw materials useage...
What can we do? Everything "OEM" is made from the same rubbish rubber, not the original formulation that lasts for 30 years +
85 syncro Caravelle twin slider Oettinger T3200E-6
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by silverbullet »

PS the very same radius rod bushes were fitted to our SA and they split after 4 months of daily useage.
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

http://www.025motorsport.com

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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by syncroandy »

Eek. The ones I got were from BW in October 2018, their stock code T3501131A-ALT:

https://www.brickwerks.co.uk/trailing-a ... ative.html

JP Group, not Lemforder.. So maybe made in China and so not subject to EU regs ? Maybe a good thing on this occasion..

 
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by silverbullet »

I am done with JP group. Everything seems to be "close, but not close enough"
The only thing they seem to do well is panel pressing and cast parts.
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by syncroandy »

I've had these bushes and that's about all. They seemed fine, quite firm rubber same as OG, fitted OK, nothing to fault really.
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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by silverbullet »

I think that the box is still on a shelf holding some spare fron cv seals, I'll check the origin
85 syncro Caravelle twin slider Oettinger T3200E-6
90 SA Microbus supercharged wbx/UN1 project

http://www.025motorsport.com

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Re: Front Control arm bushes 1986 LHD Syncro T25

Post by syncro4us »

the control arms that are currently on our syncro appear to have the longer piece of the core tube ie that bit with the three raised pips on towards the rear and the front has the rubber bush in contact with the mounting bracket. They are old eg 30 years and need replacing so until they come off I am not 100% sure. There must be a VW contact somewhere who has worked on these over the last 30 years that can confirm things?
cheers
Kevin

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