Author Topic: model M right side bearing inner race direction  (Read 2334 times)

Scooter4

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model M right side bearing inner race direction
« on: October 27, 2023, 05:03:14 PM »
Good evening,
I noticed a lot of end play on my crank shaft when fitting up parts and I think the right side bearing inner race was installed on the wrong side.  The inner race was facing the inside of the engine and I was able to drive the bearing out, but I am thinking the inner race should be facing the flywheel.
I cant tell from parts books, does anyone know.  Refer to attached image of bearing.

Please let me know.
Thank you,
Scooter

Ricks

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Re: model M right side bearing inner race direction
« Reply #1 on: October 27, 2023, 05:58:56 PM »
I’ve built numerous model M engines, and have never seen a bearing like that.  What is the bearing number?

Do NOT pound bearings in and out of the case, that is how you crack the case.  The procedure is to heat the case, I like doing it on the gas grill outside so it doesn’t stink up the house.  The bearings will just about fall out. Installation is the same, except I put the bearings in the freezer for about 30 minutes, and they go right in without  having to beat on anything.
Rick

pd

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Re: model M right side bearing inner race direction
« Reply #2 on: October 28, 2023, 06:09:12 AM »
Interesting .
I'm guessing someone has been in that motor before .
Looks like a roller bearing . Very doubtful the factory installed it . Pretty sure they used only ball bearings .
Most likely , there will be a # stamped on the outer race edge .  What is it ?

And , how much is 'a lot' of end play ?

Pete . :)
Goes around , Comes around . :)

Scooter4

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Re: model M right side bearing inner race direction
« Reply #3 on: October 28, 2023, 06:34:31 AM »
Good morning,
It is a Timken R1304.  Do you know a number of one that would normally be in there? I can compare them. May be better when installed the correct way.
I wonder if it is why the parts book shows three different bearing numbers?
I did not measure the endplay.  Probably 1/8".
I agree about not pounding them out.  I drove it out because I checked it and moved with light force. Otherwise, I use a couple of propane torches because I dont have a grill.
Please let me know.
Thank you,
Scooter

Ricks

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Re: model M right side bearing inner race direction
« Reply #4 on: October 28, 2023, 08:20:24 AM »

They have used 2 different bearings on the inside of the case. I'm not sure why, but I just match it up to the one I remove. 

Inside Wide Main  5205-2RS  25x52x20.6
inside Narrow Main 6205-2RS  25x52x15
Outside Main  6304-2RS  20x52x15

I have also seen the wider bearing come in a single row bearing, as opposed to the double row number I posted.  I'm not sure it matters at all.
Rick

Scooter4

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Re: model M right side bearing inner race direction
« Reply #5 on: October 28, 2023, 08:57:43 AM »
Thank you for the information.
I will compare dimensions to the one I have.
Thank you,
Scott

Scooter4

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Re: model M right side bearing inner race direction
« Reply #6 on: October 28, 2023, 03:33:41 PM »
I turned the bearing around so the thrust would be in the correct direction and have about .015" end play now.
My inner bearing is Koyo 6205 and no spacer.  I did see a note in the manual that eventually they did not need it. 
Thank you,
Scooter

Ricks

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Re: model M right side bearing inner race direction
« Reply #7 on: October 28, 2023, 04:02:06 PM »
I turned the bearing around so the thrust would be in the correct direction and have about .015" end play now.
My inner bearing is Koyo 6205 and no spacer.  I did see a note in the manual that eventually they did not need it. 
Thank you,
Scooter

If you used the wide bearing, you probably wouldn't need a spacer at all.  Good that you got it figured out!
Rick