Page 2 of 2

Re: Gears advice.

PostPosted: Wed Oct 03, 2018 3:47 pm
by Danbretta
Warkton Tornado No.1 wrote:Having watched the video, I would suggest that you need to eliminate the chance of the cluster rubbing with the crankcase/miss-meshing with the loose gears by fitting the endplate (it doesn't need to be fixed securely) so that the cluster can be pulled into it's correct position by tightening the clutch nut.

If that does not eliminate the noise, remove the cursor entirely & try the same test.

Many cursors are machined out of alignment & catch on first gear internal faces &/or dogs & I have taken to re-using old OEM cursors with re-ground dog faces because new cursors are so poor......


Thanks for your advice, I'll try this tonight.

Re: Gears advice.

PostPosted: Wed Oct 03, 2018 7:42 pm
by kennystag
Any luck.

Re: Gears advice.

PostPosted: Wed Oct 03, 2018 9:59 pm
by Danbretta
Didn't get the chance to look at it tonight. Will attempt tomorrow.

Re: Gears advice.

PostPosted: Thu Oct 04, 2018 12:21 am
by Fast n Furious
Have you shimmed the layshaft correctly as described in the Sticky manual? Your U-tube vid shows excessive play. There should only be 3 to 11 thou' of end float here.

Re: Gears advice.

PostPosted: Thu Oct 04, 2018 9:04 am
by Danbretta
The first video I uploaded showed the gearbox when I first took the chaincases off. The tolerance was way off and the kickstart wasn't seated correct in the chain case. I reshimmed it with a 2.4mm which game a tolerance of just under 0.1 mm that I believe to be acceptable. I've since stripped it back and will give each part an inspection again before reinstalling.

Re: Gears advice.

PostPosted: Fri Oct 05, 2018 8:05 pm
by Danbretta
Tonight's rebuild uploaded.

https://youtu.be/RK3Qjs7Tl08

I've got to back in and reshim again as it's out of tolerance now...? Rear hub torque up so will inspect again tomorrow if I have the patience.

Re: Gears advice.

PostPosted: Sat Oct 06, 2018 8:26 am
by HxPaul
Mine makes that kind of sound,I thought it was just the gears meshing,so I left it.That was two years ago and its run alright since then.

Re: Gears advice.

PostPosted: Sat Oct 06, 2018 7:04 pm
by Danbretta
The amount of times I've had the gears in and out of the case recently I'm tempted to leave it however it sounds next time I put it together. I've ordered a few shims as I discovered the shim I was using was slightly out across one plane. It was throwing the tolerance out and pinching the feeler gauge when rotating the layshaft.

Re: Gears advice.

PostPosted: Mon Oct 08, 2018 7:35 am
by kennystag
Is it not just the gears meshing, it should be quieter with oil running round the gears .
Good luck
Stag
:)

Re: Gears advice.

PostPosted: Mon Oct 08, 2018 9:04 am
by Danbretta
Hi Stag,
When I rotate the rear hub while pulling the cluster in and out there's a sweet spot where the noise softens right off. Hopefully when its torque and shimmer up it finds this spot. Otherwise as you say the oil should tone it down.
Thought I'd check with the forum before I put the chain case on in case the noise was highlighting an issue before I put the case on. This is my first rebuild.

Re: Gears advice.

PostPosted: Mon Oct 08, 2018 9:37 am
by kennystag
Best of luck Mate.
Stag
:)

Re: Gears advice.

PostPosted: Mon Oct 08, 2018 6:05 pm
by Warkton Tornado No.1
The second video is a vast improvement on the earlier version.

For total peace of mind, you could have done the same test but without the cursor in place, as previously suggested ;)

Lambretta gears are spur & the noise is therefore inherant as there is a compromise between strength & quiteness. The pressure angle (the slope of the gear face) generally becomes louder with a steeper angle as the individual teeth 'ring' as they make contact with the gear that they mesh with. Helical gears are not so strong but are a lot quieter, though tend to make a whining noise.

(I have a feeling that another brand of scooter may use helical gears, but can't think of the name. Apparently, the whining noise is supposed to be similar to some of the owners, but I'm sure that must just be a silly rumour......)

Re: Gears advice.

PostPosted: Tue Oct 09, 2018 8:04 pm
by Danbretta
Thanks, I wasn't sure what level of noise was acceptable from the gears. Think I'll go ahead and put it all back together and add the oil. While I'm at it I'll take the top end off and inspect before getting the exhaust back on. I'm sure there will be another thread from me when I get stuck into the piston end.
Thanks for all the help those that posted. I'll upload another vid ones it's all together.