Author Topic: Transmission Needle Bearing broken??  (Read 810 times)

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Offline bdillworth

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Transmission Needle Bearing broken??
« on: September 19, 2020, 04:48:59 PM »
1971 cb500 four.

Had issues shifting into 2nd but neutral and 1st was working. Just would let me shift past that.
So after further inspection I found that the end of the needle bearings metal snapped off! Sorry if I’m wording it wrong.. pictures should help with that.

Anyone ever seen this happen before? If so, what’s a easy fix instead of splitting the cases?  :o

Offline bryanj

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Re: Transmission Needle Bearing broken??
« Reply #1 on: September 20, 2020, 12:06:13 AM »
I have heard of, but not personally seen, the roller cage breaking but never the outer fracturing.
I would suspect the bearing locating peg was not located properly and crackef the outer but you can only prove that by splitting cases, which you have to do anyway.
I can see a lot of wear in the brass bush or the pushrod, was that broken?
You may end up getting a complete used box to get that bearing
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline bdillworth

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Re: Transmission Needle Bearing broken??
« Reply #2 on: September 20, 2020, 03:23:57 AM »
I’ve have driven  this bike for over 5 years on and off, never had any issues with shifting gears. If the needle bearing pin wasn’t properly set in its groove, then wouldn’t I have know that by now?

 I’m hesitant more to jb welding the snapped off end back on and seeing if that works. If not, splitting the cases will have to follow. Splitting cases is the correct way to do it but I just rebuilt the top end this year...  :'(


Offline bryanj

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Re: Transmission Needle Bearing broken??
« Reply #3 on: September 20, 2020, 09:16:49 AM »
You can leave the top end in situ ans split the cases, did not know you had been driving it 9 yrs as was not in first post and my crystal ball is broken
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline dave500

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Re: Transmission Needle Bearing broken??
« Reply #4 on: September 20, 2020, 02:08:40 PM »
jb weld wont fix that and shouldnt be attempted!you cant buy that bearing anymore so try and find a new transmission,or maybe a 550 motor?

Offline bryanj

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Re: Transmission Needle Bearing broken??
« Reply #5 on: September 21, 2020, 12:48:13 AM »
500 only bearing and they do crop up on ebay occasionally
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline Little_Phil

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Re: Transmission Needle Bearing broken??
« Reply #6 on: September 21, 2020, 01:41:29 AM »
Is that 91022286016 (also 91022286004). CMSNL have a couple (but will probably cost more than an s/h box) and it is a CB250 part and also a lot of early CB/CL350s? Or have I got the wrong part?