Trans. GEARBOX

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Norcoastal

Norcoastal

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So I got a great deal on a ransmission ($75.00). It seems to be complete and from what the PO told me, it was working when removed.

Any thoughts as to what I should do? If I tore it apart, are there serviceable things that need to be done? Does it make sense to leave it alone?

I have the original trans case with numbers that match the engine cases and frame; one idea was to take it apart and put all the parts in the matching trans case, or...I could just leave it alone. My preference would be to use the matching trans case.

I’ve never opened up a transmission on Norton, but I have on Triumphs and BSA’s and I know some times it’s better to leave it well enough alone.

What do you guys think and advise?

Is a Norton transmission a pain in the ass? If I open it up with gears spill all over the place? Should I leave it alone and just put it in the cradle?

Any thoughts will be appreciated.

Thanks
 
Norcoastal said:
So I got a great deal on a ransmission ($75.00). It seems to be complete and from what the PO told me, it was working when removed.

Any thoughts as to what I should do? If I tore it apart, are there serviceable things that need to be done? Does it make sense to leave it alone?

I have the original trans case with numbers that match the engine cases and frame; one idea was to take it apart and put all the parts in the matching trans case, or...I could just leave it alone. My preference would be to use the matching trans case.

I’ve never opened up a transmission on Norton, but I have on Triumphs and BSA’s and I know some times it’s better to leave it well enough alone.

What do you guys think and advise?

Is a Norton transmission a pain in the ass? If I open it up with gears spill all over the place? Should I leave it alone and just put it in the cradle?

Any thoughts will be appreciated.

Thanks
Click to expand...
The answer is in the question.
 
If all the shafts and bushings are good, then swapping cases should be pretty simple. I did the obligitory layshaft bearing replacement that everyone seems to do eventually. I was fearful that I would get it apart and have a nightmare situation. In a certain way, it can only go together one way, so that part is a snap. My gears and bushes were buttery smooth, so I didn't touch them. I just disassembled the box, inspected all the gears and bushings (good and good) then changed both drive side bearings and reassembled the box, and it's been smooth as silk, but it always was smooth before I did the bearing upgrades....

I would say, Don't fear it. It's actually not that hard to do... My $.02
 
o0norton0o said:
If all the shafts and bushings are good, then swapping cases should be pretty simple. I did the obligitory layshaft bearing replacement that everyone seems to do eventually. I was fearful that I would get it apart and have a nightmare situation. In a certain way, it can only go together one way, so that part is a snap. My gears and bushes were buttery smooth, so I didn't touch them. I just disassembled the box, inspected all the gears and bushings (good and good) then changed both drive side bearings and reassembled the box, and it's been smooth as silk, but it always was smooth before I did the bearing upgrades....

I would say, Don't fear it. It's actually not that hard to do... My $.02
Click to expand...
That’s what I was hoping someone would say. I’ll replace the layshaft bearing and put it back together.

Thanks
 
Gear boxes look complex but in reality they will only go back together one way. Open it up, clean it out, inspect the gears, replace the layshaft bearing and new seals and gaskets at a minimum. One critical thing to check is look for a crack in the case in the thin metal between the main and layshaft bearing bores. I've done the same thing swap the guts in one box into a matching numbers case.
 
Mick Hemmings video on GB overhaul is well worth the 30 gbp, or so, cost.

I ordered a video and Mick's choice of layshaft bearing at the same time. Have not opened up the box as yet, so I cannot comment on how easy/difficult the job.

Slick
 
Check the shafts for run out, check the gears for teeth condition and the dogs for wear. As mentioned above check the cases for cracks.

I thoroughly enjoy rebuilding gearboxes; I applaud your gravitas for jumping in; take it slow, ask questions, they are much less expensive than gearbox parts.

Best.
 
The Norton gearbox is easier to overhaul than either the Triumph or BSA especially if you go on Old Brits website. print their teardown/overhaul instructions and folow them step by step. You can also buy all your overhaul parts from Old Brits. Great site, great company, great people. Its harder to get out and put back in than it is to overhaul.
 
htown16 said:
Gear boxes look complex but in reality they will only go back together one way. Open it up, clean it out, inspect the gears, replace the layshaft bearing and new seals and gaskets at a minimum. One critical thing to check is look for a crack in the case in the thin metal between the main and layshaft bearing bores. I've done the same thing swap the guts in one box into a matching numbers case.
Click to expand...
Very helpful, thanks
 
drp said:
The Norton gearbox is easier to overhaul than either the Triumph or BSA especially if you go on Old Brits website. print their teardown/overhaul instructions and folow them step by step. You can also buy all your overhaul parts from Old Brits. Great site, great company, great people. Its harder to get out and put back in than it is to overhaul.
Click to expand...
The BSA gear box was a real pain, but I took it apart and put it back together so many times, it got easy.
 
Read the instruction manual. It will tell you how time it, when you put it back together.
 
If you have a gas BBQ grille they are great for heating up cases to remove bearing. Put the new bearings in the freezer overnight. Put the case in the grille with the opening down, get the temp up to about 350 F (helps to have an infared temp gun) and the bearings will drop out on their own or with a light smack. Drop your cold bearings in and the should either drop in or need just a little persausion with a drift. If you don't have a grille you can use the oven inside, just make sure the case is spottless. I've found heating the entire case is much better than using a MAP torch to try to heat the bearing area. The rest of the case acts as a heat sink. But Mick Hemmings does it with a torch.
 
I’m pretty sure it was Comnoz who advised against freezing the bearings. IIRC the point is that the frozen bearings will expand quite suddenly upon contact with the hot case, and can catch you out. A heated case and room temp bearing gives you a little more stability with the bearing and a little more time to get it right.
 
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