Gearbox servicing (not by Hemmings)

If you can turn the gearbox over with the clutch disengaged but not engaged, it sounds more like an engine stoppage.As its a Dominator,have you checked for conrods poking out through the crankcase,other wise it might just be a seizure.This would explain the lack of gearbox faults.The layshaft is obviously still tight in the ball bearing[thats good] and the case must be heated to release it.Otherwise it might be a bushing seizure in the box,but that would lock the box in one speed,whether its in neutral or not.As you only have layshaft third still in situ, it would be that gear seized to the shaft.If any.Regards John.

The description of the problem seems to matchthat of a Layshaft bearing failing. The symptoms of this are a kickstart which seems tosuddenly geta life of its own. Swinging round and whacking your leg where it hurts. Jumping out of gear may also occur as the layshaft drops out of being parallel with the Mainshaft.

Unless this bearing is well an truly mangled, heating the bearing housing on both sides of the shellshould allow it to be pulled outclinging tothe Layshaft. I use a loop of wire round the shaft and a stick, as a lever, to help with thistask.

Replace the bearing, if it is the standard ball race typewith the equivalent roller. Something like NJ203C3.

Hi Isaak, no problem getting the parts you require, but you will want to fix whatever caused those parts to wear.

From Norvil's website:

040071PLATE - KICKSTART PAWL STOP040042STOP - KICKSTART - THE ONE SUPPOSEDLY NOT AVAILABLE

http://www.norvilmotorcycle.co.uk/040042.htm

Skip Brolund

Using a correct rivet punch,

http://www.centaurforge.com/Nordic-Forge-Rivet-Set-Punch-with-Concave-Face/productinfo/305/

and a good whack with a hammer should do the job. Don't try to just strike the end with a hammer, you will hit all over the place!

Previously tom_mortensen wrote:

Using a correct rivet punch,

http://www.centaurforge.com/Nordic-Forge-Rivet-Set-Punch-with-Concave-Face/productinfo/305/

and a good whack with a hammer should do the job. Don't try to just strike the end with a hammer, you will hit all over the place!

mick hemmings dvd is excellent and should answer all your problems!!

Previously Isaak wrote:

Hi there!

I have started this challenge that the AMC gearbox in my Dominator 88 is asking for. It is the first time I open a gearbox of any sort, and I am finding it rather exciting. My issue:

A few months ago, while riding, I was about to drop a gear (to 2nd I think) when the change lever felt to be blocked. The engine stalled, I pulled aside and I were unable to move the kickstart anymore. Only when clutching in the kickstart would turn. I am not sure what the problem is, but I presumed it has to do with the gearbox. I didn't want to take the whole gearbox from the frame. I know it is easier to work on it, but unless I need to, I prefer to leave it mounted. I am now at the stage where the clutch is off and all the gearbox inners have been removed, apart from the layshaft (with 4th and 3rd gear), the 4th gear on main shaft, camplate and quadrant.

1) I am unable to remove the layshaft from the gearbox. I don't know if it only needs a good pull or if something else is preventing it from coming out. Any ideas?

2) So far I have not seen any broken bits, and the wear of the gears are almost non visible. So I am a bit disappointed, worried that I am doing much more work than needed... I was expecting a bit of broken metal at the bottom of the box. Given that I have stripped it down, what would you recommend to replace even if not visibly worn (Apart from the obvious gaskets)?

Thanks in advance for your comments!

Isaak

Windsor, UK

Hello Well I have seen both the VHS and DVD of this gear box rebuilds and I seen the bad practices in them too , so we sent them back , and Did it my way . It was like falling off a log so easy to do, you do need some home made tools to hold things like the two different clutch Holding tools I have made one is to hold the clutch boss the other is too hold the clutch center to change out the center rubbers also I made a bearing removal tool for mainshaft bearings . heating the gearbox housing is done by a oven I have in the workshop . Safety always comes first . preparation before starting a job. But really Norton gearboxes are easy to do . And so it the engines too there not rocket science. yours anna j

Previously anna jeannette Dixon wrote:

Previously Isaak wrote:

Hi there!

I have started this challenge that the AMC gearbox in my Dominator 88 is asking for. It is the first time I open a gearbox of any sort, and I am finding it rather exciting. My issue:

A few months ago, while riding, I was about to drop a gear (to 2nd I think) when the change lever felt to be blocked. The engine stalled, I pulled aside and I were unable to move the kickstart anymore. Only when clutching in the kickstart would turn. I am not sure what the problem is, but I presumed it has to do with the gearbox. I didn't want to take the whole gearbox from the frame. I know it is easier to work on it, but unless I need to, I prefer to leave it mounted. I am now at the stage where the clutch is off and all the gearbox inners have been removed, apart from the layshaft (with 4th and 3rd gear), the 4th gear on main shaft, camplate and quadrant.

1) I am unable to remove the layshaft from the gearbox. I don't know if it only needs a good pull or if something else is preventing it from coming out. Any ideas?

2) So far I have not seen any broken bits, and the wear of the gears are almost non visible. So I am a bit disappointed, worried that I am doing much more work than needed... I was expecting a bit of broken metal at the bottom of the box. Given that I have stripped it down, what would you recommend to replace even if not visibly worn (Apart from the obvious gaskets)?

Thanks in advance for your comments!

Isaak

Windsor, UK

Hello Well I have seen both the VHS and DVD of this gear box rebuilds and I seen the bad practices in them too , so we sent them back , and Did it my way . It was like falling off a log so easy to do, you do need some home made tools to hold things like the two different clutch Holding tools I have made one is to hold the clutch boss the other is too hold the clutch center to change out the center rubbers also I made a bearing removal tool for mainshaft bearings . heating the gearbox housing is done by a oven I have in the workshop . Safety always comes first . preparation before starting a job. But really Norton gearboxes are easy to do . And so it the engines too there not rocket science. yours anna j

I agree that the Norton gearbox is relatively easy to work on. However the Mick Hemmings video instruction is excellent, especially for the novice. Mick knows more than most about the Norton engine and I know who I would rather trust for advice.

JMc

Unfortunately, I have been a little too busy to keep up to date with this thread but it sounds to me like there are still a few issues that need sorting.

Both the Mick Hemmings and John Hudson Gearboxvideos/DVDs are excellent for stripping and rebuilding but do not always help with identifying causes of problems. I have recently refurbished2 Norton Dominator plus 2 early Commando gearboxes. One of the Commando boxes was quite low mileage but had exhibited the usual signs of a failed Layshaft bearing.

Actually the bearing had not failed but had been replaced, by a previous owner,by a standard roller bearing. This had allowed the Layshaft to drift sideways and the Kickstarter shaft then followed ituntil the Pawl had jumpedits Stop Plate. The steel Kickstarter Bearing Ring was also driffing sideways and to add to the misery, the bush in the 4th Kickstart Gear had got mashed.

Fortunately fixing the mess was straightforward, using the correct replacement bearing, bushes and some bearing fix where needed.

One useful tip that John Hudson gave me was to assemble the gearbox upright by clamping the mainshaft in a vice. You get a nice clear view of where everything goes and the selector arm studsslip into the quadrant plate and gear clusters much more easily than if the box is horizontal.