1st 2nd gear noise

Hi John

Welcome to the club, I don't know the correct answer to your question, but would suggest you buy/borrow Mick Hemmings excellent DVD on the AMC gearbox rebuild, he seems to be the expert on such matters. He rebuilt my box for me a few years ago, because of a bad 'whine' on third gear, and he ended up replacing most of the parts, and it is now fine.

I would also have a look at the primary chain/clutch etc,.............The shop has the DVD for sale (£17.50)

Once again welcome

Regards John O

Having had my box appart a few times to address gearchange issues I would happily pull it down in a trice , and back together in an hour,so don't be fritt of it. I would want to look at bearings/bushes , which mostly can be got at with the box in situ. Certainly worth a look.

Stab in thedarkbutletstry theobvious;

Primary tootight? Needs at leastan inch in the middle

Layshaft bearing? Try movingtheclutch basket around, does it wobble?

Thrust washer? pull/ pushthebasket to see how much itmoves

Mainshaft bearing,try thedrivesprocketformovement.

Yourdescriptionsoundslikeouterbearing wear, which isonly just inside the outercover soeasy to take apeek. But make thetests first. Gearsonly whinewhenthey are not meshing properly, either the pair areworn or the supportfor the shaft they are on isnotstable. The lowgearsare neartheouter side of thebox( kick startside),hencea bearingfaulttherewill showupmore on thelowergears.

As Robertsays; Dont beafraidof thebox itisarelativelysimple unit.

Good Luck,andhope itssoemthing simple

Jon

The AMC gearboxes have pairs of meshed gears. Each pair consisting of one bushed gear and the other splined. Wear in the bushes will cause whining in first or second or both. There is no thrust washer in the AMC box but wear in the ball bearings will allow the respective shafts to move about allowing some of the gears to contact parts they should be clear of.

The best move would be to strip this gearbox and check all the chunks. The help of someone who has done this before will be a really smart move. Getting hold of the Norton Gearbox strip/rebuild DVD would also make sense. The Haynes book is difficult to follow for most people new to a dismantle then rebuild.

If anyone would like a preview of the AMC gearbox innards in action .........head for the search site box (top left) and type in Roadholder 296 April 2012. here you will find Les Howard's excellent diagrams of how all the bits fit together and work. Or possibly, as in John's case, do not appear to be.

I agree with Jon, the bearing in the inner cover or bushes, My bearing and its replacement were all too tight in there loosing the running clearance, the housing was undersize ,I don't think the Norton machinery was at its best around that time.Perhaps it had not yet wore out in 1957 !!.

Previously jonathan_newton wrote:

Stab in thedarkbutletstry theobvious;

Primary tootight? Needs at leastan inch in the middle

Jon

I'm all in favour of slack rather than tight but think an inch is overkill for a primary. I wouldn't have more than 3/4" at the tightest point.