general layout of front wishbone fixing points and polybushes

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

your statement is only valid for metalasitc bushes, where the inner sleeve is bonded to the rubber-bush..

with polybushes or uniballs it doesnt matter when you tighten the bolts.

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

a bit of an update:

i wondered why the inner sleeve was flush with the PU-bush after assembling:

the wishbone eyelets seem to be wrongly made from marlin, they are a few millimetres too wide.

when both PU half-bushes are fitted into the eylet there is a gap between the bushes. and this is exactly the measurement which prevents that the inner metal-sleeve sits correctly.

narrower eylets--> less gap--> inner sleeve would stick-out --> everthing fine.

as the wishbones are like they are, modifying (narrowing) the PU-bush collar was the only way for solving the problem. job done!!

[b_caswell]

Re: general layout of front wishbone fixing points and polybushes

https://www.youtube.com/watch?v=_z6OEohnPKw you might find this of interest does go on a bit but first ten mins covers the point raised

[andyf]

Re: general layout of front wishbone fixing points and polybushes

Just noticed on wheeler dealers that the jag front end uses the same arrangement.

SDC11386.JPG

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

thanks for the youtube video...by luck i already viewed that a few days ago.

and it shows exactly the problem on my car.

the video shows the bushes fitted to a mass -production car...where the bush-eylet on the wishbone is given by the car manufacturer. means the bush-manufacturer has to respect the given measurements from the car-manufacturer.

here we are talking of a kitcar where the wishbones are "handmade"...so theoretically the bush was first, and the eylet could have been suit to match. which unfortunately didnt happen.

surplus the eylets have a rather big tolerance speaking of the internal diamter, means some bushes need to be forced in, others slide in easy.

consequetively this has an effect how easy the crush-tube / sleeve passes through the bush, and how much force is needed for rotating the bush around the sleeve.

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

everything sorted..front suspension is back togehter. now the bushes are rotating nicely over the inner sleeves.

new front 005.jpg

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

next update:

as i wasnt happy with the alignment of both wishbone eylets, surplus i needed more castor on the driver side i replaced one of the polybushed eylets for a rod end bearing / uniball.

to make things look identical, the same will be done also on the passenger side. there, mostly for eyelets alignment reasons.

new front 009.jpg

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

razr xt925 jan 2015 418.jpg

[Mike]

Re: general layout of front wishbone fixing points and polybushes

Is the pivot point on the threaded rod end bearing shorter from the wishbone than the polybush pivot point?
From the photos it is difficult to see what length advantage you gained by fitting the rod end bearing.

I am interested in this idea for my Cabrio which has the same issue, but has a much more difficult way to make the adjustment, where the fixing bracket has shims behind it which have to be slackend off, then new shims added, then tightened up again.

Mike

[Sportster-Green]

Re: general layout of front wishbone fixing points and polybushes

both sides (polybush as well as rod end) have the same distance from the wishbone to pivot point.

but i had 2 problems:

as the thread inside the wishbone is M16, i needed to use a M16 rod end bearing. but M16 bearings are very long....so no way for getting it fitted to the car, without resulting in extreme positive camber.

i used a female type bearing, shortened the bearing body to a measurement which, when fully screwed into wishbone, the camber was set at around -1,5degrees.

http://www.ebay.co.uk/itm/251297538711?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

in the shortend rod end body, i screwed-in a M16 set-screw which was than welded together with the rod end body.

as the rod end bearing is narrower than the polybush eyelet, i had now the possibility moving the wishbone further backwards for getting a better castor setting.

the problem on my car was, that on the left side castor was correct on the right side i had negative(!!!) castor and with the wide polybush eyelets there was no way correcting it, as i had zero shims on that car.

with the narrower rod end i could correct it, but i have now some shims on the rear side of the whisbone

another advantage: the alignment of front and rear pivot point --> the long bolt holding the wishbone in place is now less under flexural force.

oh...i forgot:

the pivot point of the whisbone is M10...the inner sleeve of the polybush eylets was for M10...but for the m16 rod-end i needed to fabricate some adapter sleeves from 16mm to 10mm

you can also buy some adapter from M16 to m12 and M12 to M10 here but you still need to modify them a bit:

http://www.ebay.co.uk/itm/161213623619?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT