Gearbox, layshaft bush, driveside

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
User avatar
Posts: 2651
Joined: Wed Dec 14, 2011 1:02 am
Location: ESSEX UK

Re: Gearbox, layshaft bush, driveside

Postby Ozmadman » Fri Feb 14, 2020 9:22 am

ajscomboman wrote:Well the quotation did say 32mm and not 31.5mm as well as stating steel cage. If they come in wrong I'll have wasted 1hr of my life yesterday on the phone talking them through our requirements!

:beer:
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed

Member
Posts: 6679
Joined: Wed Sep 01, 2004 12:00 am
Location: WEST SUSSEX UK

Re: Gearbox, layshaft bush, driveside

Postby SPRIDDLER » Fri Feb 14, 2020 10:08 am

ajscomboman wrote:If they come in wrong I'll have wasted 1hr of my life yesterday on the phone talking them through our requirements!

Good on yer. From my experience (in a salaried job) of exasperating conversations with various suppliers I doubt that it was your first time and it won't be the last.
:beer:
I poke badgers with spoons.

Member
Posts: 55
Joined: Sat May 18, 2019 4:50 pm
Location: Cheshire UK

Re: Gearbox, layshaft bush, driveside

Postby vigo » Tue Feb 25, 2020 8:07 pm

My main bearing RNU205 is now fitted and things are taking shape. Only anomaly is that if I tighten the left hand thread nut up very tight as recommended in "fixit"it will the bind up the bearing. I think the ring under the sprocket is closing on the end of the rollers. I will pinch it up and lock with the washer, feels great then.
When I get back to UK next week there should be a layshaft bush, drive side from AMOC waiting, they have stock.
Now this is another confusing one, I have a couple ofseals 040005x ring kickstarter shaft from AMOC. They have an internal diameter of 25mm and are far too big for the shaft, am I missing something here?

Member
User avatar
Posts: 1018
Joined: Sat Jun 20, 2015 8:38 am
Location: Chester, UK

Re: Gearbox, layshaft bush, driveside

Postby clanger9 » Tue Feb 25, 2020 8:39 pm

Hmm, it shouldn't bind when the nut is done up tight. There should be plenty of space at the end of the rollers to allow the output sprocket to "float" axially in the bearing.
Is the outer seal fully home?

Your o-ring 040005 sounds like it's the wrong size. It has an internal diameter of 16mm and just sits on the step of the shaft, as per this photo. It has negligible sealing effect (given the usual endfloat on the kickstart shaft), so it's common to fit two o-rings side by side to try and rectify this...
Gm6JXp2KJncoTvEN.huge.jpg
You do not have the required permissions to view the files attached to this post.
1966 AJS Model 14 250 CSR cafe racer
1989 Moto Morini Dart 350
1993 Ducati 750SS

Member
Posts: 55
Joined: Sat May 18, 2019 4:50 pm
Location: Cheshire UK

Re: Gearbox, layshaft bush, driveside

Postby vigo » Tue Feb 25, 2020 8:53 pm

Well the main Bearing seal is as recommended fixit or Bill Redford assy at least 5mm from surface. Should it be pressed home as far as possible?
I have meanwhile decided as you recommend to fit 2x o rings but I understand these x seals should fit where the o rings do and are much too big in i/d. They cost only pence so it doesn't matter but it's another head scratcher.

Member
User avatar
Posts: 1018
Joined: Sat Jun 20, 2015 8:38 am
Location: Chester, UK

Re: Gearbox, layshaft bush, driveside

Postby clanger9 » Tue Feb 25, 2020 9:25 pm

It's difficult to say exactly where the seal should be, but there needs to be end float on the bearing.

I just put together a spare output gear assembly and the bearing roller track measures 6.82mm. So the rollers in your bearing need to be shorter than this to give it some endfloat.
IMG_1175.jpg


Admittedly this is a worn bearing and it's not done up super tight, but you can see how much "float" there is on this type of bearing in this video:
https://youtu.be/R_ppKNU6vi8
You do not have the required permissions to view the files attached to this post.
1966 AJS Model 14 250 CSR cafe racer
1989 Moto Morini Dart 350
1993 Ducati 750SS

Member
Posts: 55
Joined: Sat May 18, 2019 4:50 pm
Location: Cheshire UK

Re: Gearbox, layshaft bush, driveside

Postby vigo » Wed Feb 26, 2020 9:22 am

Thanks Clanger that did the trick. I set the seal a bit further in and now there's no binding at all.

Member
User avatar
Posts: 1018
Joined: Sat Jun 20, 2015 8:38 am
Location: Chester, UK

Re: Gearbox, layshaft bush, driveside

Postby clanger9 » Wed Feb 26, 2020 9:48 am

Excellent! Should be fine now. I'll add a note to the iFixit...
1966 AJS Model 14 250 CSR cafe racer
1989 Moto Morini Dart 350
1993 Ducati 750SS

Member
Posts: 55
Joined: Sat May 18, 2019 4:50 pm
Location: Cheshire UK

Re: Gearbox, layshaft bush, driveside

Postby vigo » Tue Mar 03, 2020 8:20 pm

Just opened the new layshaft bush from club spares. It has a 4.5mm thick rim and apart from some manufacturing burrs which need polishing off, all is good. The surprise is the i/d does not need reaming and has some nice spiral lube grooves. I checked the i/d with a go/no go guage I made as my new layshaft is in Germany. Complicated but I will not travel with a lump of metal in hand luggage I've already lost a timing light.

Member
User avatar
Posts: 1360
Joined: Sat Oct 09, 2010 8:17 pm
Location: SWANSEA UK

Re: Gearbox, layshaft bush, driveside

Postby cbranni » Tue Mar 03, 2020 9:18 pm

Complicated but I will not travel with a lump of metal in hand luggage I've already lost a timing light.


I lost a 12" shifter like that, just forgot it was in my laptop bag, don't ask

Colin
only dead fish go with the flow

PreviousNext

Return to G5 / Model 8

Who is online

Users browsing this forum: No registered users and 0 guests