bodger
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| posted on 11/2/07 at 03:03 PM |
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Polybush fitment
Fitted a top wishbone arm last night & it was so tight it could hold up the whole wheel up on its own! and that was after filing the tube seam out
& removing any powder coating left inside the tube. Despite being reassured that the crush tube should be a tight fit I think its way too tight.
Just found this info on the net about fitting poly bushes which seems
to make a lot of sense so it looks like I'll have to tweak the bushes on a lathe.
What I can't understand is why nobody else has had this problem.
Where is a good source for stainless crush tubes ?
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MkIndy7
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| posted on 11/2/07 at 03:20 PM |
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Possibly a silly question but did you use any grease when assembeling them?.
I didn't think they needed them until about 2 months after the car was on the road and it delevoped a terrible squeeking noise lol
Amazing the difference a bit of grease makes!
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BenB
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| posted on 11/2/07 at 03:41 PM |
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I just tickled the end edges of the bushes to allow easy insertion then gave them a good slap of copper slip. Quite stiff initially but sweet now.....
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mark chandler
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| posted on 11/2/07 at 04:08 PM |
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My experience of polybushes, on landrovers, is that once you have pushed in the bush the steel insert onced greased up can be pushed in by hand.
The bush will rotate on the insert/crush tube but once you have taken up the free space either side of the bush it will take a lot of force to
twist/lateral move.
Either way you should not be able to pick up the car, maybe the wishbone tube is a little small so you now have to compensate on the crush tube.
Regards Mark
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bodger
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| posted on 11/2/07 at 05:26 PM |
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Yes, I lubed them up with plenty of moly grease but it still took a lot of force in the vice to push them in. I'm sure they will free up a bit
when on the road but I still think they're way too tight a fit to work properly.
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flak monkey
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| posted on 11/2/07 at 05:31 PM |
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Mine were the same. Inner tubes very tight in the poly bush itself. Seems to work fine though...! And they dont take that much force to move once the
bones are bolted up to the chassis. Though they will support their own weight quite easily.
David
Sera
http://www.motosera.com
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Dave Bailey
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| posted on 11/2/07 at 10:31 PM |
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I fitted my bushes recently to my Velocity and they needed to be pt in with a nylon mallet. The thing is that the steel tubes actually are shorter
than the bushes and so the wishbone will not move on the tube. Is this normal? The assy instructions state tighten up then slacken the nut until the
bolt starts to turn.......
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flak monkey
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| posted on 12/2/07 at 07:30 AM |
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Not this again...
The crush tube should be held firmly between the bracket by the bolt, which means do the bolt up FT...
Any other way the bush really isnt doing its job. Search for previous posts on polybushes, plenty of detail.
David
Sera
http://www.motosera.com
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rusty nuts
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| posted on 12/2/07 at 08:46 AM |
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If the bushes/ crush tube are too tight when the bolt is tightened so that the arm will not move IMO there will be to much strain on the arm and the
brackets. Stripped all my arms off after being on the road for a year , removed all weld burrs etc from inside arms retried and still found them too
tight. On measuring the crush tubes were found to be too short . Ended up skimming the top hat section of the bush . Reassembled with rubber grease
and tested each arm by nipping in vice an rotating arm around crush tube. Ride and handling are now very much improved without jarring my spine
everytime car hit a bump. Suspect some suspension arm failures may ?? be due to overtight bushes/crush tubes
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bodger
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| posted on 12/2/07 at 12:53 PM |
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Quote from Fisher Fury build manual:
'Fit the rocker arm first, this pivots on an M12 x 225 bolt, using tube ferrule and nylon tophat section
bushes. These bushes will be a tight fit in the rocker arms, the tube ferrule must be 0.5mm longer
than the bushed arm and must be able to move freely. If the ferrule is too tight in the nylon, ream out
with an old bolt slotted and fitted onto a drill with emery cloth. Some resistance is acceptable – too
loose and you will have slack suspension!'
Considering the difference it will make to the handling it sounds like it's worth spending a bit of time getting this bit right.
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procomp
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| posted on 12/2/07 at 01:59 PM |
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Hi what has been qoueted from the fisher build manuel above is the correct way of doing the job.
Any other way means that the suspension is going to suffer from stiction bad enough to cause problems on the car when driving .
Whether you are able to realize you have and be able to notice these problems when driving is another question alltogether.
cheers matt
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Dave Bailey
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| posted on 12/2/07 at 07:12 PM |
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I take the point.....I don't know how many Luego people have built their suspensions in the way that he manual states. My crash tubes are
shorter than the bushes...... Looks like I will be taking it all apart again. What doesn't make sense is that the front suspension has some
spacing washers fitted which means that the crash tubes will not move in the bushes but the arms will move on the bolt. Have a read of the Luego
manual on the web site.
strange
Dave B.
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rusty nuts
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| posted on 12/2/07 at 07:14 PM |
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There wasn't a manual when I built my suspension and yes the crush tubes are too short. Thats why I skimmed the top hat section
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Dave Bailey
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| posted on 12/2/07 at 07:36 PM |
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Just sent Dean @ Luego a note to get some more bushes..... Did you say you left the crash tubes protruding by 0.5 mm?
thanks
Dave B
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rusty nuts
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| posted on 12/2/07 at 09:55 PM |
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Probably more like 0.25mm , Dean was told about problem at Newark last year .
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