gearbox layshaft wear

[johny]

For fun Ive got a Vitesse 2L gearbox in bits and the layshaft is very good but you can see the normal wear patterns on the top half of the shaft so I wondered if any gearbox gurus could advise me on the possibility of reusing the shaft but rotated by 180deg? It means the shaft locating roll pin will be sticking up not down in the extension housing but it looks as if it will still do its job of preventing the shaft from rotating....

[Pete Lewis]

well thats a call for compromise or...utopia 

is there any signs of distress as that means the rollers are also in need of replacement 

its not a call i would wish to recommend

 pete

[johny]

no I think the layshaft is very good as theres no discernible wear ridge and its just a dulling of the surface on the sides where the load has been taken so I would happily reuse it rather than risk a pattern part replacement but obviously it will last longer if the load can now be taken on the opposite side. The only disadvantage I can see is that in the usual position if the roll pin came out (possible as they only push in) it would be trapped in the pocket of the extension housing whereas reversed it will be free to travel around the housing....

[Nick Jones]

27 minutes ago, johny said:

For fun Ive got a Vitesse 2L gearbox in bits and the layshaft is very good but you can see the normal wear patterns on the top half of the shaft so I wondered if any gearbox gurus could advise me on the possibility of reusing the shaft but rotated by 180deg? It means the shaft locating roll pin will be sticking up not down in the extension housing but it looks as if it will still do its job of preventing the shaft from rotating....

Yes, this is something that gets done, provided the shaft shows nothing worse than "burnishing" or the merest hint of pitting on the wear side.  Mick Papworth has even been known to recommend it.  Anything wear lip you can feel with a fingernail, or more extensive pitting, forget it.

Nick

[johny]

Thanks Nick, thats really handy and I'll make sure the roll pin is really in there!

[daverclasper]

Can the roll pin be removed and Loktited in, or maybe best left alone?

Edited April 20, 2020 by daverclasper

[Pete Lewis]

it is just a short spiral roll pin  easy to remove with any sort of grip.

and tap back in place 

Pete

[rogerguzzi]

Hello Johny

                      I have done that on one of my gearboxes I made a small plate to hold it in the new position (belt and braces!) 

I fit new needle rollers

Roger

[johny]

Yes when I removed this layshaft the roll pin just fell out! I've tapped it back in and it feels solid but there's obviously some fretting action from the layshaft in use which is concerning if the shaft is rotated 180degs...

[Pete Lewis]

the roll pins have been known to come out with an oil drain

a good call for a magnetic plug  roll pins  are pretty hard /tough they dont do teeth much good 

[GT6M]

drill thru shaft, its easy

then loctite in,

I,d be look,n at the needles under a magnifying glass.

then yee,l see pits in em,

they cheep enough t,replace, so replace em

 

And, whilst yer at it, bung a front thrust wesher in the back,

it,ll be same size as thrust face, so will be 100% cover

as agenst 70% cover oft original wee,n

 

need t,check the end of laygear for ridges, remove ridges, so its flat

file,grind,  back of thicker thrust so its a good fit into box and layshaft

then file either side oft tang  doon aboot an  1/8th inch, so that 1st gear no touches bigger thrust

 

Note, used gears, dont always give a good syncro actionee

as the steel cones wear, so yee,l need a decent supply of sync cones t,get the best match

or biggest gap between gear face an back of sync cone

As all sync cones are no the same, slight variances, so ive fun oot.

 

the gap in 2nd gear  and gap in 1st gear hub, fill both wid v cold SLD lube

it,ll stop the split collars frae drop,n oot, which saves ye tek,n it t,bits agen

dont use grease.. same for the needles too, plenty of  cold SLD t,hod the needles in spot

and a dummy mainshaft is a must, or needles can, and doo drop oot, then wen ye put shaft in,        then its most likely a full strip doon agen, unless ye can re fit the needles in situ,

hard , but dooable

and turn gb upside doon t,fit layshaft assembly, as gravity is better than a bit of wire pull,n gears up.

Meb,e some use t,ye an others.

 

 

M

[johny]

Thanks. It looks like a good box except that all the synchros are heavily worn which I didnt expect (maybe 2nd and 3rd) considering the great condition of the layshaft. It has been apart recently though so maybe it had a new layshaft + thrusts and nothing else. Unfortunately the mainshaft tip has a patch of pitting so isnt really reusable unless a sleeve is fitted...

[thescrapman]

You can open out input shaft and Gond end of mainshaft down, the thee is a sleeved bearing that fits