123hotchef
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the nylock did work loose that is what i dont under stand
- Thread starter 123hotchef
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the nylock did work loose that is what i dont under stand
PhillipM
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The nylon bit is not to stop the nut from coming loose, it's to stop the nut coming off the bolt if it does come loose, the nut itself will only loosen if there's an issue with the torque settings or a manufacturing fault, there shouldn't be anything turning against it to try to undo it so it doesn't matter if the threads are left or right or any of that, the nut should clamp the steel boss solid against the arm, the boss should not turn at all, the bush should flex.
the snooper
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If the wishbone fr
If there is enough force against the nut it will turn and become loose, all the nylon insert does is stop it vibrating along the threads and falling off
normspanners
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well there is a huge force trying to undo the rear nut it's the upward motion of the arm as you brake that upward movement will try and twist the bush insert anticlock and undo the rear nut and then clockwise at the front nut therefore tighten the front nut. Under normal suspension movement there is not as much force passing through the bushes but as you brake the upright 'wants' to turn with the wheel so increasing the load on the bushes as they restrict the uprights rotational movement.
If the rubber bush is a harder compound rubber the nut may not be able to stand all those forces passing through it.
Escort rally cars used to undo the right hand / OSF anti roll bar to track control bar nut, under extreme braking if a nyloc was used instead of a castellated nut and split pin, road cars would run OK with nylocs but the old group one rally cars used to slacken off the nuts because of the weight but the left side never slackened because that same force was tightening the left nut.
As a matter of interest did the originals have castellated nuts and split pins?, many of this type do, for this very reason.
123hotchef
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No the originals just had standard nuts probably with thread lock on them but I can not be sure. The originals also look and feel better quality.
Migmac
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123hotchef
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Rust would be holding the originals on tooHarriet sorting you out?
Ha Ha, yes she has mate new one will be with me today. Looking at the originals they are still in great shape I don't know why I bothered replacing them to be honest, it aint like ~I have plenty of time on my hands.
Migmac
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Hopefully the replacements are ok. Well I thought I was done working on my truck but ain't to be. Truck was sitting ticking over and oil was dripping again. Just replaced the oil cooler pipes and thought that one had work loose, nah the oil pressure switch was leaking. Got the new one today, are they just a metal to metal fit or should there be a fibre washer or something to seal it?
123hotchef
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if it is a classic mine is tapered so it seals itself just don't over tighten it or it can crack the housing.
They only sent me 1 replacement wishbone and told me to use thread lock on the other side we will see if that works, actually I should have my m14 nylocks today or tomorrow so I will double the nuts up
123hotchef
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is it leaking from the actual centree part where the spade connector is? if so that will cure it
123hotchef
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stops the chassis rotting
Migmac
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The front end of my chassis should be mint then !
PhillipM
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Whilst I can see a rally car or a modded car fitted with poly bushes having a huge force from friction (which isn't there in a twisting rubber bush) and vibration and flex slackening the nut, the force from a rubber bush twisting on a road car should be tiny compared to the clamp load on the sleeve from an M14 nut - you should be around 6-8 tonnes of clamping load on both faces. Castellated nuts have the same problem as nylocks, they only stop the nut coming off, they don't stop it from coming loose, which would make the bush rattle on the bolt and lead to snapping the bolt again.
I'd suggest it's not the braking moment trying to undo it - it's normal movement upwards - which of course does occur under braking.
The braking moment will react through the upright and try to turn the top of upright forwards around the wheel centre, pushing the front of the arm inwards, the rear pulled outwards, which it would do even if the suspension was locked, not really twisting the nut itself. Some Caterham guys found exactly this a few years ago - replaced the upper joint to the upright with a rose-type joint - which promptly bent forwards under braking.
I'd hazard that if there isn't a material defect in the threaded section, that the bush inner tube is being pushed into that plated washer on the spindle on the other side of the bush enough to back off the clamping force of the fully torqued nut. If they don't want the arm back, it'd be interesting to cut it apart to see.
Regarding the comment earlier about serrations in the bush tube - I've never seen one with serrations - they would simply smear flat I would think. I looked at the picture and thought they were indentations from something like a nordlock washer - now they take some undoing when fitted correctly!
If you think about it - what ever force, if that's what it is, is undoing the rear nut in suspension bump, it should equally be undoing the front one on rebound - or even re-torquing the rear one . . . ;-)
Suitable threadlock (ie retainer) given time to cure on clean threads will hold pretty much anything - I've sheared screws before that stuff has given up.
The braking moment will react through the upright and try to turn the top of upright forwards around the wheel centre, pushing the front of the arm inwards, the rear pulled outwards, which it would do even if the suspension was locked, not really twisting the nut itself. Some Caterham guys found exactly this a few years ago - replaced the upper joint to the upright with a rose-type joint - which promptly bent forwards under braking.
I'd hazard that if there isn't a material defect in the threaded section, that the bush inner tube is being pushed into that plated washer on the spindle on the other side of the bush enough to back off the clamping force of the fully torqued nut. If they don't want the arm back, it'd be interesting to cut it apart to see.
Regarding the comment earlier about serrations in the bush tube - I've never seen one with serrations - they would simply smear flat I would think. I looked at the picture and thought they were indentations from something like a nordlock washer - now they take some undoing when fitted correctly!
If you think about it - what ever force, if that's what it is, is undoing the rear nut in suspension bump, it should equally be undoing the front one on rebound - or even re-torquing the rear one . . . ;-)
Suitable threadlock (ie retainer) given time to cure on clean threads will hold pretty much anything - I've sheared screws before that stuff has given up.
doubleboost
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Many bushes are seated to give a bite on initial assembly
A properly designed / manufactures assembly will never come loose with just plain nuts
The clamping force will be immense It will take a mechanical fault to loosen it
"big end bearing caps ect" just use plain nuts or bolts
The nylock is for safety to stop a loose nut unwinding
123hotchef
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new arm has been delivered looks fine to me the bolts on either end are tight so I think I will leave them alone and see not sure it is a nylock now or if it is blue thread lock. Any way i just stuck it in a vice and rotated it to how the old one was ready for fitting at the weekend probably now
normspanners
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Just as a matter of interest was the nut that slackened on the near side the foremost nut ?
A lot of suspension bushes have serrations in the bush crush tube some have d shaped holes in the washers and flats on the pins to prevent the rotational movement transmitting to the fastener.
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