Norton gearbox # 142754

seattle##gs · Saturday at 4:36 PM

What year is this GB? Gears have no marking on them...no AHA or AH.

It is 47 degrees outside. If I turn the GB over the bearings fall out on their own. On a 75 degree day they will be loose as a goose. The only solution short of buying a new gear case (approx $400) is to use some super strong Loctite on the bearing and case and assemble. Sounds iffy to me but has anyone done this and inspected 500 miles later? Or 1000 miles later? Did the bearings stay put or is the loctite all gone?
Perhaps there is an epoxy that would work and the bearings would be a permanent installation.

I have 4 gear cases in the same condition. I hate to throw them out.

L.A.B. · Sunday at 2:54 AM

142754 should be early 1971.

marinatlas · Sunday at 3:14 AM

seattle##gs said:
What year is this GB? Gears have no marking on them...no AHA or AH.

It is 47 degrees outside. If I turn the GB over the bearings fall out on their own. On a 75 degree day they will be loose as a goose. The only solution short of buying a new gear case (approx $400) is to use some super strong Loctite on the bearing and case and assemble. Sounds iffy to me but has anyone done this and inspected 500 miles later? Or 1000 miles later? Did the bearings stay put or is the loctite all gone?
Perhaps there is an epoxy that would work and the bearings would be a permanent installation.

I have 4 gear cases in the same condition. I hate to throw them out.

Comnoz said years ago , you can use jb weld ...worth a try !

kommando · Sunday at 3:32 AM

Loctite from bitter experience does not work in an alloy engine to hold steel bearings, the heat cycles and the differential expansion rates of the two metals will break the bond in less that a 1000 miles. In a pre-unit gearbox its different as the casing does not get as hot but the loctite grade has still to be a high temperature grade.

marshg246 · Sunday at 9:05 AM

seattle##gs said:
What year is this GB? Gears have no marking on them...no AHA or AH.

It is 47 degrees outside. If I turn the GB over the bearings fall out on their own. On a 75 degree day they will be loose as a goose. The only solution short of buying a new gear case (approx $400) is to use some super strong Loctite on the bearing and case and assemble. Sounds iffy to me but has anyone done this and inspected 500 miles later? Or 1000 miles later? Did the bearings stay put or is the loctite all gone?
Perhaps there is an epoxy that would work and the bearings would be a permanent installation.

I have 4 gear cases in the same condition. I hate to throw them out.

Both Loctite and Permatex have special bearing retaining compounds. One for close fitting and one for loose fitting. Sounds like you need the close fitting. Normal Blue or Red thread lockers are NOT the correct thing to use. In all cases, the bearing retainers are high temperature. They also require reading and following the instructions - they are not instantly strong.

DennisMo · Sunday at 12:10 PM

I read of a loctite that is specifically made to fill gaps when bearings are inserted into housing.
"LOCTITE® 660 High Strength Retaining CompoundIf you want a product that enables re-use of worn bearing seats, keys, splines or tapers, try LOCTITE® 660."

baldy · Monday at 6:23 AM

Not the best solution. You can carefully grind small notches into the od of the bearing. Then you punch the aluminum case into the notch to retain the bearing. Ugly but seen done.

Mofosheee · Monday at 6:44 AM

Mine wasn't quite as bad as what you described. I used the hi strength Locktite as suggested above. No issues

NickZ · Monday at 10:07 AM

If the bearing is not held tight enough in the case and slip occurs, what is the effect / symptom / result?

Peter Restaino · Monday at 12:26 PM

seattle##gs said:
What year is this GB? Gears have no marking on them...no AHA or AH.

It is 47 degrees outside. If I turn the GB over the bearings fall out on their own. On a 75 degree day they will be loose as a goose. The only solution short of buying a new gear case (approx $400) is to use some super strong Loctite on the bearing and case and assemble. Sounds iffy to me but has anyone done this and inspected 500 miles later? Or 1000 miles later? Did the bearings stay put or is the loctite all gone?
Perhaps there is an epoxy that would work and the bearings would be a permanent installation.

I have 4 gear cases in the same condition. I hate to throw them out.

I had the same problem on my rolling basket 70 Commando S. When I tore it down found loose bearings and somebody tried to stake the bores but It doesnt work. I found a good used gearbox on Ebay. 140 dollars. Got lucky no cracks and good bores. Dont waste your time on trying to fix it because it will fail again.

David750 fastback · Monday at 3:06 PM

Loctite 603 resists 150°C
it is used to seal the bearings in the housings. It's a little tedious to disassemble but it works perfectly.
I used it for an RG 500 so that the crankshaft bearings do not rotate in the crankcases

Torontonian · Monday at 5:02 PM

Clint Eastwood . " Do you feel lucky today , Punk ?
My new build MK111 gearbox has been to and from the machine shop , to put set screws (drilled and threaded ) , into the outer- outer race (s) of both roller bearings , fitted into to the box . No chance of any looseness drifting now . Good luck with the glues .

marshg246 · Monday at 6:49 PM

Torontonian said:
Clint Eastwood . " Do you feel lucky today , Punk ?
My new build MK111 gearbox has been to and from the machine shop , to put set screws (drilled and threaded ) , into the outer- outer race (s) of both roller bearings , fitted into to the box . No chance of any looseness drifting now . Good luck with the glues .

Wow! How much did that cost? A new shell is less than $400 USD delivered to the US. And, there are often good ones on eBay for less than $50 USD.

Torontonian · Monday at 6:56 PM

I wanted both rollers to fit , tightly , main and lay .
No issues with the box being wallowed out in the shell .
Just wanted it .
Labour $150 , Both roller bearings about the same . Enjoy .

frank73x89 · 2025-01-14T07:20:37-0700

Torontonian said:
I wanted both rollers to fit , tightly , main and lay .
No issues with the box being wallowed out in the shell .
Just wanted it .
Labour $150 , Both roller bearings about the same . Enjoy .

Hi Torontonian. Just wondering what is the roller bearing number you are using on the main shaft? And any pics on where the set screws are located in your shell? TKS!

Torontonian · 2025-01-14T10:54:33-0700

Can't help much on those questions , except that the roller main is undersized to the outer circumference, so the machinist made a sleeve for it to press into place . Then the 3 set screws to hold/press it even tighter .
The roller lay is the standard recommended upgrade one , NJ203E TVP2 C3 .
Never took pics , just reassembled it all following the Old Britts article . oldbritts.com/gearbox_a.html . using a rear isolastic shim . New 1 st. gear bush , gaskets , seals and the newer style neutral switch and matching cam plate button from A.N. ( This is MK111 , I own 2 ) .
Enjoy .

Norton gearbox # 142754

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