nc24 rear bearings and axel help

[sp00ka]

after taking the bike to the mot station, it failed on front and rear wheel bearings. I have followed neo's guide on how to change the rear wheel bearings. The conclusion i have come to is that i cannot detemine whether the play has come from wear on the bearings or wear on the axel itself or is there another reason it could be ? i have the axel in two parts, the axel itself and the unit that holds the three wheel bearings. The unit that hold the three bearings, the two roller bearings on the left hand side are clean and have no play in them at all (are these two bearings the same as they both have the same code ? david silver spares told me one is a hub bearing an one is a wheel bearing is this correct ? as they said one is £10 and other £56 ) the needle bearing on the right looks absolubtley fine. ive cleaned the rear axel and there is a slight groove on the right where the roller bearings sit in between. with the wheel fitted on the axel and you wobble it with both hands there is about 2mm play with the wheel off and wobblke it from crush drive side there is minimal play. What i need to know is it the axel is worn or the inner race of the two roller bearings ? as the play is that minimal i dont want to take the bearings out if nothing is wrong. Sorry for the complicated explanation but i have attached a couple of pictures to help with understanding the problem.

[Neosophist]

perhaps both are knackered.

Did you take the grease out of the bearings to check for play?

The caged ball race comes as one bearing (it's 2 stuck together with a plastic clip (6908RS Koyo), thats the 56gbp one.

You also have the needle roller and if I remember rightly a bearing in the cushdrive cover.

Play in the wheel can come from any one of these... all the ones i've had to change the needle roller has been fine its' been the caged ball race (56gbp jobbie) thats the problem.

Not seen any kind of wear like that before though, general overal polishing of the axle where it runs in the bearing yes but not a deep groove, perhaps something was caught in the axle.

My monies still on the bearings being knackered... can be hard to tell... new bearings, re-assmeble and check for play.

[sp00ka]

In the top picture where I mark inbetween the 2 roller bearing ( the none polished part ) that's raised bit! it's only slightly raised, like a edge of a piece on paper sitting on it , maybe less , I was hoping that might be normal because if I buy the bearings and it still has that slight play in it then it will fail again !
If I buy the bearings and it sill has play it's either the needle bearing or a problem with the axel ! Will I have trouble finding a rear axel ?

[sp00ka]

Just to add does the black plastic cover on the bottom picture come off caeca use it on really tight and don't wanna break , and just checked the roller bearings codes on the bike there Elges. 61908rs double roller bearing. Makes me think maybe they have been changed before and needle rollers buggered or there a crap bearing !

[Neosophist]

Just to add does the black plastic cover on the bottom picture come off caeca use it on really tight and don't wanna break , and just checked the roller bearings codes on the bike there Elges. 61908rs double roller bearing. Makes me think maybe they have been changed before and needle rollers buggered or there a crap bearing !

Could be standard, i've always seen Koyo bearings but can't be 100% sure it's not stock.

I'd change all the bearings and re-assmeble.. it'll 99% fix your issue. If theres still play the axle is worn. You can get the specs of the axle runout and service limits from the Haynes NC30 manual (NC24 specs at the rear) to check before you re-assmeble.

Be careful changing bearings.. if you dont' know how to do it or don't feel confident then get a shop to do it, the number 1 case of premature bearing failure is damage on installation.. if you knock the cage or don't drive it straight you'll scrap the bearing and shorten its life-span. and at nearly 60quid there not cheap.

You've only got to measure the axle to see if it's in tolerance.

The black 'plastic cover' is the dust/oil seal... if you nick it or scratch it then it's scrap and you'll have to replace it, and yes it does come out. Pry under-it with an apporiate tool being very careful not the scratch the lip (inside part that touches the axle.

This seal stops water getting in and grease getting out.. if it fails your axle and bearings will rust up when it rains.

[bunker]

Thanks for the information guys, just looking for this