Norton transmission sleeping problem

Hi to all

I bought a 1974 commando. Every was perfect for a couple of months until my 2nd and 3rd gears began to make a strange sound when I disengage the clutch, like the chains or the gearbox was forcing to make the bike moving. Every thing worked "normal" until my kickstart lever began to go down and hit my mufflers when I shift in second and third gears. When I shift into 4th, the lever goes up. When I engage the clutch and make the gearbox free, the kickstart comes up. The bike starts well with one or two kicks. I checked the kickstart spring which seems to have a good tension. I also checked the primary chain tension, which seems to be also normal. Is there anyone who had that problem before?

Thanks!

Phil

Sounds like your layshaft bearing is going bad. It needs to be checked right away!. Chuck.

Hortons Norton said:

Sounds like your layshaft bearing is going bad. It needs to be checked right away!. Chuck.

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+1
Ciao.
Piero

Several . Do NOT Ride It .

Matt Spencer said:

Several . Do NOT Ride It .

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+100---- good advice here, better to heed the warnings

Look here for the info on transmissions: http://www.oldbritts.com/gearbox_d.html

Phliper00 said:

Hi to all

I bought a 1974 commando. Every was perfect for a couple of months until my 2nd and 3rd gears began to make a strange sound when I disengage the clutch, like the chains or the gearbox was forcing to make the bike moving. Every thing worked "normal" until my kickstart lever began to go down and hit my mufflers when I shift in second and third gears. When I shift into 4th, the lever goes up. When I engage the clutch and make the gearbox free, the kickstart comes up. The bike starts well with one or two kicks. I checked the kickstart spring which seems to have a good tension. I also checked the primary chain tension, which seems to be also normal. Is there anyone who had that problem before?

Thanks!

Phil

Click to expand...

I agree with others this sounds very much to be the layshaft bearing failure.
Extremely dangers to ride it because as it continues to fail the pieces can jam the gears, locking the rear wheel THAT NO PULLING THE CLUTCH WILL HELP!
There are a number of threads on this issue.
I replaced mine earlier this summer.
The bearing can be replaced while still in the bike, however the box cannot be completely disassembled while in the bike if you find evidence of bushing or shaft damage involving the main shaft.
Involves a paint stripper elec heat gun to extract bearing while on layshaft, and to reinstall.
There was a recent thread on whether a high performance ball or a roller best.
I used the ball that Mick Hemmings recommnends and it avoids the need to shim for shaft end play.
Hemmings 6203 TB bearing
http://archives.jampot.dk/Technical/Tra ... anics_1987).pdf
hemmings-layshaft-bearing-t5838.html

I suggest you photograph very intensly every step so as you reassemble you see how all the parts relate.

Hope this works


http://archives.jampot.dk/Technical/Tra ... anics_1987).pdf

rx7171 said:

Hope this works


http://archives.jampot.dk/Technical/Tra ... anics_1987).pdf

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Damn I can't get this PDF to post properly. Nice Mick Hemmings show and tell ofrebuilding gearbox.

Without removing the box you could miss something. A small crack is OK but this is something of a concern
I'm glad I pulled mine out (layshaft disaster imminent)

2nd-layshaft-bearing-failure-please-advise-t17455-15.html

Jed

thank you all guys! I'am new to this forum and wow! What a community!!

I will open the gearbox and see if there are any cracks or if the bearing is jammed or what ever could it be. I already order a new layshaft bearing. I thought it would be a good idea to change it anyway.

phil

rx7171 said:

rx7171 said:

Hope this works


http://archives.jampot.dk/Technical/Tra ... anics_1987).pdf

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Damn I can't get this PDF to post properly. Nice Mick Hemmings show and tell ofrebuilding gearbox.

Click to expand...

If you delete the last section up to the 1st forward slash (/) in the address bar it opens the parent directory for this section. It looks like the 5th one is the Hemmings one.

http://archives.jampot.dk/Technical/Transmission/AMC/

Took out my layshaft and look at the bearing and seems to be in good condition.

Find that post on the forum that looks like my problem : kickstart-pulls-down-take-off-t9557.html

What would you recommend? Go at a local shop with my gearbox and make a full inspection and make the correction, buy a new layshaft and main shaft?