aka Keith
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| posted on 30/3/15 at 08:26 AM |
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suspension bush movement
Was giving the car a good spanner check at the weekend and have noticed that the top front bush of the suspension wishbone has a little play front to
back
The crush tube is tight against the bracket but the bush has about 1mm of movement front to back.
the bushes are a couple of years old, so I not sure if it is ware and tear, or can I put a nylon washer between bush and bracket like caterham do, to
take up the slack?
Yours
Craig
PS Anyone know what the OD of the crush tube is - car is MK indy.
[Edited on 30/3/15 by aka Keith]
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Doctor Derek Doctors
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| posted on 30/3/15 at 12:04 PM |
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I belive the crush tube OD is 19.05mm (3/4" )
I would expect the bushes to be slightly wider than the crush tube so that they cant shunt back and fourth. I think my fist action would be to start
with some new high quality bushes.
[Edited on 30/3/15 by Doctor Derek Doctors]
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DIY Si
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| posted on 30/3/15 at 01:34 PM |
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If I've understood it right, it sounds like your crush tube is a tad long. If you were to take it out and shorten it, or add the washer, the
play would be reduced to a reasonable amount, as there should be a little bit to stop it binding.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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aka Keith
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| posted on 30/3/15 at 01:57 PM |
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the crush tube itself fits snuggly into the bracket on the chasis, which when tightened up, allows the bush to then rotate around the crush tube, but
at the moment the bushes themselves allow the front of the top wishbone to move backwards and forwards.
If you where to grab the top front wishbone, you can move it front and backwards (along the length of the car) by a mm or two, even thought the crush
tube is tight up against the chassis bracket. Does that help explain what I am trying to say?
Cheers
Craig
[Edited on 30/3/15 by aka Keith]
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Slimy38
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| posted on 30/3/15 at 03:25 PM |
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I see that as being the fine balance between being too loose and allowing the suspension to move back and forth, and being too tight and causing
things to bind! Personally I wouldn't alter the crush tube, if you come to replace the bushes you'll then have them too tight.
When I put mine together I am going to use teflon washers both to take up the slack but also allow a smooth surface for the bushes to slide against
the bracket.
You could also consider what effect that fore and aft movement is having on the suspension geometry. For example, if it's the rear suspension
then does it actually matter that it can move?
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leon51274
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| posted on 30/3/15 at 03:45 PM |
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I might be barking up the wrong tree here but could it be that the bolt is the wrong size ie 12mm and not 1/2"
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joneh
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| posted on 30/3/15 at 05:56 PM |
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quote:
Originally posted by leon51274
I might be barking up the wrong tree here but could it be that the bolt is the wrong size ie 12mm and not 1/2"
That's the same issue I had with my Fury. Had to ream the chassis to 1/2 inch for the bigger bolts to match the crush tubes in the bushes.
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avagolen
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| posted on 30/3/15 at 08:05 PM |
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If I read you correctly, and the bush movement is just along the length of the crush tube,
you will be ok packing it to prevent it floating in that axis as long as you do not cause it to bind.
If the bush is loose on the crush tube, then the bush needs replacing.
I would not shorten the crush tube if it sits nicely in the chassis bracket and is nice and tight.
Doing so in my opinion will deform the chassis brackets from what sounds like a good fit.
HTH
Len.
The Answer for everything, but never the last word....
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aka Keith
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| posted on 31/3/15 at 12:28 PM |
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Thanks all for the replies. Have ordered some nylon suspension washers from Caterham and will see how it goes. Will double check all the
measurements and fittings and update if there is any development.
cheers
Craig
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Slimy38
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| posted on 31/3/15 at 12:58 PM |
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quote:
Originally posted by aka Keith
Thanks all for the replies. Have ordered some nylon suspension washers from Caterham and will see how it goes. Will double check all the
measurements and fittings and update if there is any development.
cheers
Craig
How much did you pay for them? I was going to get a sheet of material and get it cut, but if they do the proper things for a good price then I might
take the easy option.
I assume the ID of the washers is larger than the crush tube, IE it only packs out the bush and not the whole bracket?
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aka Keith
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| posted on 31/3/15 at 01:06 PM |
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The washers are 98p each direct from Caterham plus postage. I am sure you can get them cheaper elsewhere and I will look for an alternate
supplier.
The washers are actually 17.5mm ID and 32mm OD so the ID is slightly to small and will need reamed or enlarged to fit over the crush tube so that, as
you say, it only packs out the bush.
cheers
Craig
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40inches
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| posted on 31/3/15 at 01:08 PM |
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quote:
Originally posted by aka Keith
Thanks all for the replies. Have ordered some nylon suspension washers from Caterham and will see how it goes. Will double check all the
measurements and fittings and update if there is any development.
cheers
Craig
These? http://www.caterhamparts.co.uk/product.php?id_product=1438
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aka Keith
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| posted on 31/3/15 at 01:22 PM |
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Yip, that's the ones.
cheers
Craig
[Edited on 31/3/15 by aka Keith]
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