alfas
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| posted on 11/12/17 at 03:45 PM |
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Polybushes....are those correct?
eBay item number:
322847773565
why those bushes have grooves on the external surface?
"Poly bushes have grease retention grooves to minimise "squeak""
makes no sense, imo, as the bush should not rotate inside the wishbone eye.
the grooves should be insiede, where the sleeve sits.
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mikeb
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| posted on 11/12/17 at 04:55 PM |
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Agree, I thought the steel insert gets clamped allowing the polybush to rotate around it.
Saying that mine squeak and have huge hysteresis but only a few miles on the clock so hoping they will loosen up.
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fregis
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| posted on 11/12/17 at 05:54 PM |
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maybe grooves are also in inear side.
i glue polibushes, because they rotated in housing..... housing size what should be
But i dont like my polibushes, they to soft, quality poor... buy from ebay
[Edited on 11/12/17 by fregis]
Never be afraid to do what you are insolvent, remember: amateurs built the ark - Professionals built the Titanic.
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alfas
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| posted on 11/12/17 at 08:29 PM |
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so common conclusion about those bushes with external grooves: they could be called "a total mis-construction" 
[Edited on 11/12/17 by alfas]
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craigdiver
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| posted on 11/12/17 at 10:26 PM |
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I made the mistake of buying a set similar to those (but in black). They turned out to be far too stiff and after advice from god himself (Matt @
Procomp) I swapped for softer ones and were much easier to work with.
If it ain't broken, fix it anyway (just because).
Building - BMW powered Haynes Roadster/442E hybrid.
Volvo C30 T5 Polestar
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CosKev3
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| posted on 12/12/17 at 11:58 AM |
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Bit of a worry that when the manufacturer of a part doesn't understand how it works 
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alfas
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| posted on 21/12/17 at 07:56 PM |
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i sent him several quesions about this issue...he is insisting that he is right that the bushes MUST rotate inside the wisbone...i tried to explain
him the correct working principle several times, incl. several links to other webpages.....conclusion: he insists on his opinion .
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alfas
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| posted on 12/1/18 at 12:44 PM |
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as they havent been expensive i purchased a set from this company Polytorq
shipping took 1 months thanks to ebay´s famous GSP (global shipping program)...and here comes the facts:
the inner sleeves are made of mild steel, with a rough, unmachined surface
the sleeve has an OD of 18mm and the hole in the bushes are 17.5mm
means extrem tight fit, plus rough surface...those bushes will never pivot over the sleeve, the complete assembly will rotate inside the wishbone
eye....a total mis-construction.
the supplier was replying:
This is our preferred design as tested with other users. The grade is 95 shore A. There are grease retention grooves on the outside of the bush. It is
deliberately tight on the sleeve. The principle is that the sleeve is clamped rigid between the pivot points. With the forces of suspension this
allows the poly to rotate either on the sleeve or inside the arm location and by so doing reducing the chance of poly squeak. Regards. Mike
my reply:
a polybush, whatever brand, MUST rotate/pivot on the sleeve...never the bush inside the wishbone.
any design which does not follow this principle has been wrongly designed.
why the above described principle is followed by ALL other brands of polybushes?
why the above described principle is written in all books about suspension?
why the above described principle is described in every web-forum about suspension?
why all other brands are using a sleeve which has a polished / smooth surface and yours have a rough / matt surface?
suely not because ALL the others are wrong!!
their reply:
I have been involved in the manufacture of polyurethane bushes since their concept in 1990. There are many schools of thought on how they should
perform
I do not wish to enter into a technical debate with you
Please return for a full refund including the cost of postage
Good luck with your project. These bushes are used on OEM vehicles. We are happy with our product
They are happy with our product
They have a lifetime guarantee against failure
my reaction:
those bushes went straight into the bin!!
[Edited on 12/1/18 by alfas]
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Mr Whippy
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| posted on 12/1/18 at 12:56 PM |
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quote:
my reaction:
those bushes went straight into the bin!!
pity as he was about to give you a full refund including the cost of postage... kind of shot yourself in the foot there
[Edited on 12/1/18 by Mr Whippy]
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Camber Dave
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| posted on 12/1/18 at 02:11 PM |
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Quote
" These bushes are used on OEM vehicles. We are happy with our product"
Polytorqe may supply bushes to be used as he described in a cast iron component but our 'thinwall' wishbone eyes make them totally
unusable.
I only use Superflex. All come with Stainless sleeves, grease and some bushes including ARB mounts have a grease retaining cross hatch INSIDE the
bush.
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rusty nuts
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| posted on 12/1/18 at 06:59 PM |
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I can't help it wonder how many wishbone failures that used to be a regular problem on locost suspension was down to incorrect poly bushes and
crush tubes?
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alfas
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| posted on 18/1/18 at 12:30 AM |
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quote:
Originally posted by Mr Whippy
quote:
my reaction:
those bushes went straight into the bin!!
pity as he was about to give you a full refund including the cost of postage... kind of shot yourself in the foot there
[Edited on 12/1/18 by Mr Whippy]
not really....as a (trackable) parcel from my country to UK woud have cost me roughly 10,-€..plus my efforts to pack them, plus toime for driving to
post offie, plus fuel ....return-trip 15km...... the refound would have been the original purchas price, plus the original shiping from UK to my
country...in total 19,-pound....
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