Author Topic: Output shaft bearing replacement?  (Read 2859 times)

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Offline mattcb350f

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Output shaft bearing replacement?
« on: March 17, 2008, 01:51:26 PM »
There are two bearings in the transmission of my 350F which are no longer available from Honda. They are the two large bearings, one of them being on the output shaft (sprocket shaft) next to the seal.

My bearings are fine. No grity spots and no side to side movement so I think they are still fine. I know I should replace them but that might be hard to do since I don't know where to get them.

If they were available I would just replace them but since they're not, I'm considering using the old ones.

What do you think? Has anyone reused these bearings or had bearing failure stories to share because they used old ones?

I read one post about a 400F blowing this particular bearing... but due to a bad seal

 Thoughts folks....

 Matt.
1974 CB350F,  1980 CB125S,  1981 XL80S
Non Honda's: 86 & 87 Husqvarna 400wr's

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Offline mystic_1

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Re: Output shaft bearing replacement?
« Reply #1 on: March 17, 2008, 02:03:46 PM »
I've considered re-using old bearings before but the cost does not outweigh the risk in my opinion.  You should be able to read off the bearing number on the side of the bearing race and find an equivalent bearing from a variety of suppliers.

mystic_1
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Offline City Boy

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Re: Output shaft bearing replacement?
« Reply #2 on: March 17, 2008, 06:29:47 PM »
The problem I think is the groove for the bearing retainer.The bearings themselves conform to International standard but the groove is not.If you cannot locate new,and your used ones pass a close inspection,use them.
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Offline Bodi

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Re: Output shaft bearing replacement?
« Reply #3 on: March 18, 2008, 06:36:47 AM »
The groove can be ground into a new bearing. This is an open (no shields or seals) bearing so buy a sealed bearing (2RS or equivalent) to keep the insides clean during grinding and have the groove cut - a bearing supply house should either get it done or will know where to take it. Once the groove is done, pry out the bearing seals and wash the grease out with solvent. I had to do this some years back for a CB77 bearing.

Offline City Boy

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Re: Output shaft bearing replacement?
« Reply #4 on: March 18, 2008, 06:53:52 AM »
Good to know.Tks.Rock On
'52 Kiekhaefer Mercury Rocket Hurricane KG4H
'70 750/RC 1000 Original Owner
'83 1100F

Offline Soos

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Re: Output shaft bearing replacement?
« Reply #5 on: March 18, 2008, 07:27:02 AM »
I have done a similar bearing modifications before.
I had to cut a step on the OD on a double tapered timken bearing once.

Any capable machine shop can groove a bearing race for you.
The smaller the shop(job shop) the more likely they are to be willing to do it for you.

I work at a large machine shop, and know of several co-workers with lathes and mills in their garage/basements.
They do oddball jobs that job shops shy away from.
Mostly due to the time involved just getting to the broken part.
at a min. of 60.00/hr... machine shop time can add up quick.


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Offline mattcb350f

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Re: Output shaft bearing replacement?
« Reply #6 on: March 18, 2008, 09:20:31 AM »
Oke dokey, thanks fella's. My machinist should be able to cut a new grove, or make one wider.

Just one more question....

How does one get the bearings off the shafts? are they pressed on (requiring a puller) or what.

The Honda manual and Clymer manual completly ignore these bearings and make no mention of how to get them off, or diagnose them for that matter  ::)

 cheers, Matt.
1974 CB350F,  1980 CB125S,  1981 XL80S
Non Honda's: 86 & 87 Husqvarna 400wr's

My CB350F resto: http://forums.sohc4.net/index.php?topic=30467.0
Gallery at:
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Offline bryanj

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Re: Output shaft bearing replacement?
« Reply #7 on: March 18, 2008, 10:52:22 AM »
As these bearings run in oil they rarely fail, as long as it is not rough and has no play i would re-use it.
Its also quite probable that Honda have upgraded to a new part number--have you tried asking at Dave Silver? and finally yes you need a press to get them off
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).

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Offline Cvillechopper

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Re: Output shaft bearing replacement?
« Reply #8 on: March 18, 2008, 11:04:08 AM »
I have been able to get them off and back on using a open end wrench just big enough to get around the shaft and a hammer.  Not a standard way to do it and far from the recommended method, but it can work.  You just have to make sure you don't hit the shaft, rotate the wrench after each hit, and use more of a tapping hit than trying to get it off all at once.  Make sure the end of the shaft that's on the outside of the bearing is on a block of wood or hard plastic, not metal or concrete.  The hard part is hitting the wrench close enough to the shaft to transfer the force while holding the wrench perpendicular.  I've used various assistants with this and found that a couple cardboard boxes stacked inside each other provide enough resistance on the outter end of the wrench to keep it parallel.  They crush a little bit with each hit about as far as the bearing moves(at least they did for me).

With the right precautions and patience, you can get it off and re-use it, no problem.  It is risky though so only use this method if you're willing to accept the possibility of dinging the shaft (that's not slang for anything Terry) or damaging the bearing. 
It is the mark of an educated mind to be able to entertain a thought without accepting it.  Aristotle

Offline ttr400

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Re: Output shaft bearing replacement?
« Reply #9 on: March 18, 2008, 12:17:16 PM »
The bearings on the main and counter shafts are both the same (part# 91002-286-008).
The main shaft bearing can be replaced. the countershaft bearing is part of the shaft.
The bearings and the countershaft are discontinued. I have found them on ebay from time to time.
To remove the countershaft bearing, support the bearing and use a press on the shaft.  first the oil seal collar will come off and then the bearing.  The oil seal collar has an o-ring fitted as oil is fed direct from the oil pump through the seal and collar to feed the countershaft.
However Bryanj is quite correct in that I have never found one that has needed replacing.
Hope you understood that. (Oh, the countershaft, also known as the output shaft)

Kevin
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