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Z900 front hub

Posted: Fri Oct 25, 2019 8:59 pm
Author: Richard Q
Hi all, I have a small problem, or maybe two.

I dropped the Z into a local bike shop to get a couple of new tyres. This chap knows Zeds, in fact there was one exactly the same as mine there when I turned up :shock:

I picked it up, and rode home but found I had no speedo. It worked when I got there but not on the way home. He was locking up when I left, so I couldn't just go back. I jacked the front wheel off the ground and spun the front wheel, but it was stiff and only turned about a third of a turn before stopping :|

So, I dropped the wheel out.

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When I dropped the wheel, this fell out onto the floor. Now, I am assuming this is a anti squeal shim for the brake pad and as it's been crushed and was keeping the pad against the disc. There don't appear to be any anti squeal shims in the exploded diagram of the calipers though, it is supposed to be there, or is it something else?

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I cleaned out the speedo drive, and cleaned up the gears, they were perfect, so new grease and put it back together. Then put the axle back in and spun the wheel, drive didn't turn? I took the axle out and had a good look around the hub, nothing seemed amiss so I put it back in and this appeared.

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It appears to be an aluminium distance piece, although on closer inspection, it's actually two stuck together. After a lot of head scratching, and finding it doesn't appear in the exploded diagram I put the hub back together without it, and lo and behold the speedo gear turns.

The question is, do I put it back together without the aluminium washer thingies, and beat the shim flat with hammer and put it back together? I'm asking because I do sometimes do some really daft things and don't want to with the front wheel of my Z.

Oh, another question, do the collars need to be torqued or just hand tight? The left hand one was loose when I dropped the wheel out.

:)

Re: Z900 front hub

Posted: Fri Oct 25, 2019 10:17 pm
Author: CAT3
Your man might know his Zeds, but he obviously can't refit a wheel properly.

I would guess either the speedo drive was not engaged correctly with the plate on the hub or more likely the speedo inner cable was not correctly located onto the speedo drive.
That plate is off the back of brake pad, it's obviously come off while your man was refitting the wheel. He can't of check spun the wheel after he'd finished refitting it. You quite lucky really there not any damage to the disc.
No idea what those two washer are though.

There is a torque for the two axle nuts as well as the four axle clamp nuts. There is also a correct way round to fit the actual clamps, there should be no gap at the front.

Re: Z900 front hub

Posted: Fri Oct 25, 2019 10:36 pm
Author: Richard Q
Thank you CAT3

I am of the opinion that the spacers have put the speedo drive 3mm further out than it should be, and that has allowed the gear to run off of the worm drive for the cable, if that makes sense? Hence it works without the spacers, but doesn't when they're there.

It was engaged correctly.

Do you know what the torque figure is for the axle collars/nuts as it's not in the manual? (I have a Z1 manual and a 1976 Z900 parts list).

Cheers

Richard

Re: Z900 front hub

Posted: Sat Oct 26, 2019 9:54 am
Author: CAT3
Spacers should not be there at all, no idea what or where they're from !

Front axle nuts should be torqued to 51 - 65 Lbs.ft.
Front axle clamp nuts should be torqued to 11.5 - 16 Lbs.ft.

I always use new nylon nuts for the clamps & after positioning them the correct way round, (there should be arrows cast into each clamp, which should point forward) & ensuring they are square, I nip the front nut up & then tighten the rear nut to the minimum torque figure. It always feels a bit too tight to me to tighten these nuts up to the specified maximum.

Re: Z900 front hub

Posted: Sat Oct 26, 2019 12:26 pm
Author: Richard Q
Cheers CAT3

All back together now, axle collar bolts to 58 lb ft (spacers removed), caliper bolts to 21lb ft (plate hammered flat and refitted properly), clamp bolts to 14lb ft (arrows pointing forward), speedo connected up and working, and front wheel spins freely.

I might change the oil and filter now, but I might go home as it's cold and damp down here :(

Richard