Which polyurethane bushes?

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Mr Spigot
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Which polyurethane bushes?

Post by Mr Spigot »

I have read many of the posts here about poly suspension bushes and their superiority to the old rubber bushes, but wondered if there is any difference between the vast range of poly bushes available? Some mention different colours giving different hardness, although others say the colours are just random. Then there is Powerflex, SuperPro, Polybush etc. etc. with just as many variations in price. I have seen some posts giving scientific measurements of softness/hardness, but they don't seem to transfer into the adverts by the various outlets, so I am none the wiser.
Is there any consensus on which ones are best or what differences there may be between them?
1960 2 door with 1275 Midget engine - WOI 577
1952 MM convertible with original engine - MWD 305
philthehill
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Re: Which polyurethane bushes?

Post by philthehill »

I have fitted SuperFlex poly bushes Pt No: SF 0258-95K. Which can be also used for the rear spring eyes/shackles.
The colours are just random. I have measured the Shore hardness of different coloured poly bushes with a genuine Shore test meter and I can confirm that the colour in relation to harness is not relative.
This is my genuine Shore test metre
Shore gauge.JPG
Shore gauge.JPG (1.25 MiB) Viewed 315 times
The majority of poly bushes of what ever colour are around the 75 Shore hardness mark.
The main differences between them are the thickness of the shoulder which if not of the correct thickness can give fore and aft movement of the pin in the front suspension eye.viewtopic.php?t=75201 See
poly bushes.JPG
poly bushes.JPG (576.74 KiB) Viewed 324 times

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Mr Spigot
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Location: East Sussex
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Re: Which polyurethane bushes?

Post by Mr Spigot »

Thanks. So from your investigations, the material is much the same in all these bushes, but the dimensions can vary between suppliers? I am focusing on the rear suspension at the moment and will be looking at the front later in the year.
Does anyone do poly bushes for the Spax shock absorbers?
1960 2 door with 1275 Midget engine - WOI 577
1952 MM convertible with original engine - MWD 305
philthehill
Minor Maniac
Posts: 10768
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Which polyurethane bushes?

Post by philthehill »

There is little variance between the shore hardness of the poly bushes offered by the various Minor parts suppliers.

As regards the Spax dampers - Yes - Super Pro Pt No: SPF0718-80K as fitted to my Spax gas dampers.
The dampers have large eyes at either end and the bush is able to be pushed into the eye before fitting.
This is the Spax kit I have fitted to the front of my Minor. The original Spax mounts have been modified to suit my modified suspension: https://www.ebay.co.uk/itm/174632566597 ... gKBzfD_BwE
Before ordering check the size of your damper eye as some Spax dampers have a small eye and a Metalastic bush fitted to the eye.

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