5th Gear problems.

[PhilMill63]

So I started the engine re-build today and while checking the gearbox clusters I see damage on the teeth of both 5th gear cogs, first question, is this a common issue? second question am I likely to find a decent pair of gears? anybody on here got some by chance?? I'm kicking myself because when I stripped the bike I found the gearbox main shaft bearing broken up and should have checked the clusters then Pictures attached to show the extent of the problem.
I am not confident doing the strip of the clusters myself so ideally need somebody to do the rebuild of the clusters and fit the new bearings too. Anybody able to help please.

[warren3200gt]

Yeah, I've got some gearbox clusters only problem is I've no idea what they are from. Came with a box load of bits with a project bike.
Anyway to identify them anyone? Have they got numbers on them anywhere? They are still on the shafts but as I didn't need them that's where they stayed.

[PhilMill63]

So is this something the 900 is known for?

[zed1015]

So is this something the 900 is known for?

No!
It's just high mileage or infrequent oil changes , hard use etc etc..

[warren3200gt]

Rob, is there any way of determining what my clusters are from so I might be able to help Phil out?
Or were all the 900/1000/1100 clusters the same?

[zed1015]

All 903/1015 clusters are the same ratios.
There's subtle differences with output shaft length on the post Z1 models and the mk2 gears are a bit tougher but they are all basically the same gearbox.
(998/1100 clusters are different ratios and tooth form with larger dia output shafts and don't fit without modification)

[warren3200gt]

Thanks Rob.
Phil if you can post up specs of the gears you need I'll see if they match anything I have.

[PhilMill63]

Thanks Rob.
Phil if you can post up specs of the gears you need I'll see if they match anything I have.

Thanks, I'll take some pics, its only 5th gear I think. I'll have a good look today.

[PhilMill63]

If I can bump this back up, Warren looked at his clusters and they are different (different number of teeth) so I'm still on the hunt. I have found an NOS gear in the US (pt no. 13136-042) for the shaft on the clutch side but still on the hunt for the one on the sprocket shaft.

Another question, I cannot remove the bearing behind the sprocket, can anybody suggest a bearing puller that will fit in the small gap behind this bearing? don't want to buy something that will not fit, its quite tight there. Once I get that bearing off I should be able to strip the shaft and get to the 5th gear.

What's the thought if I cannot get the gear and only replace one? the one I can get seems to be the worse of the two but don't fancy doing another engine strip if I get noisy gearbox.

Thanks, Phil

[PhilMill63]

Nobody even able to offer advise on the bearing puller

[ADRIAN H]

If I can bump this back up, Warren looked at his clusters and they are different (different number of teeth) so I'm still on the hunt. I have found an NOS gear in the US (pt no. 13136-042) for the shaft on the clutch side but still on the hunt for the one on the sprocket shaft.

Another question, I cannot remove the bearing behind the sprocket, can anybody suggest a bearing puller that will fit in the small gap behind this bearing? don't want to buy something that will not fit, its quite tight there. Once I get that bearing off I should be able to strip the shaft and get to the 5th gear.

What's the thought if I cannot get the gear and only replace one? the one I can get seems to be the worse of the two but don't fancy doing another engine strip if I get noisy gearbox.

Thanks, Phil

I’d send Ralph @ Bikertoolbox a email to discuss. He’s Z1OC south west area rep. https://www.bikerstoolbox.co.uk/

[r3sc]

I’d never replace a single damaged gear and leave other damaged components in there. No way, keep hunting for the parts you need.

[PhilMill63]

I’d never replace a single damaged gear and leave other damaged components in there. No way, keep hunting for the parts you need.

I did replace both in the end, managed to find them.

[r3sc]

Top job! Glad you got it sorted.

[chrisNI]

I’d never replace a single damaged gear and leave other damaged components in there. No way, keep hunting for the parts you need.

I did replace both in the end, managed to find them.