The Ford Barn

Grampy · 10-13-2011, 02:09 PM

A question came up in conversation today. In the 1930 transmission, does the bearing need to be pressed onto the main shaft, or should it slide on without needing to be pressed?
We've consulted two recognized authorities and have gotten conflicting answers.
It's been quite awhile since I built my transmission, but I seem to recall pressing the bearing on.
What do you guys think?
Thanks

Doug in NJ · 10-13-2011, 02:15 PM

If there is nothing to hold the inner race firmly to the shaft, it could creep and the shaft could get worn at that spot. Does the U-joint clamp the bearing in place?

Doug

Tom Endy · 10-13-2011, 02:24 PM

Most all of the transmissions I have worked on I have had to press the old front bearing off and press the new bearing on. The rear bearing is a different story. Most seem to slip on and off. Occasionally I have had to press them on and off. I suspect they originally were a press fit but must have spun somehow. The stop on the mainshaft and installation of the U-joint holds ithe rear bearing in the proper place.

Tom Endy

Robert Putnam · 10-13-2011, 04:09 PM

Rule of thumb is that a bearing is always installed with a race fastened to the part of the machine that rotates. In your case the shaft rotates so the inner race of the bearing should be a press fit onto the shaft. If the shaft is worn so that the race is a slip fit, loctite can be used to secure the bearing race to the shaft.

Doug in NJ · 10-13-2011, 05:11 PM

I assume he was talking about the rear bearing. Doesn't that fit over splines, which might make a tight press fit problematic? I expect the front bearing to be a press fit.

Doug

Purdy Swoft · 10-13-2011, 05:55 PM

Sponsored Links (Register now to hide all advertisements)

I lay the bearing over a hundred watt light bulb for a while to heat up and expand, I then slip the bearing in place, no press needed. This method was published in one of the national club magazines many years ago and has always worked for me.

Wick · 10-14-2011, 05:28 AM

I use a bearing heater when I can. The light bulb works well too. 220 degrees bearing temp and it will fall right on.

Grampy · 10-16-2011, 11:33 PM

It is the rear bearing we were talking about, and, yes it does fit over splines, which is exactly what started the conversation in the first place.

Thank you guys for your comments.

James Rogers · 10-17-2011, 08:33 AM

Neither bearing needs to be pressed on or should not be pressed off. Either might be a tight fit but, both are held on by a clip so, pressing is not needed. The front by a cup circlip and the rear by a small standard circlip.I have never had to press one on, just some light tapping with a hammer and pipe but, some are a bear to remove.

10-13-2011, 02:09 PM	#1
Grampy Member Join Date: May 2010 Posts: 61	Press the bearing or not A question came up in conversation today. In the 1930 transmission, does the bearing need to be pressed onto the main shaft, or should it slide on without needing to be pressed? We've consulted two recognized authorities and have gotten conflicting answers. It's been quite awhile since I built my transmission, but I seem to recall pressing the bearing on. What do you guys think? Thanks

10-13-2011, 02:15 PM	#2
Doug in NJ Senior Member Join Date: May 2010 Location: Princeton, NJ Posts: 965	Re: Press the bearing or not If there is nothing to hold the inner race firmly to the shaft, it could creep and the shaft could get worn at that spot. Does the U-joint clamp the bearing in place? Doug __________________ My '31 S/W sedan project:http://31ford.dougbraun.com My restoration diary: http://dougbraun.com/blog

10-13-2011, 02:24 PM	#3
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: Press the bearing or not Most all of the transmissions I have worked on I have had to press the old front bearing off and press the new bearing on. The rear bearing is a different story. Most seem to slip on and off. Occasionally I have had to press them on and off. I suspect they originally were a press fit but must have spun somehow. The stop on the mainshaft and installation of the U-joint holds ithe rear bearing in the proper place. Tom Endy

10-13-2011, 04:09 PM	#4
Robert Putnam Member Join Date: May 2010 Posts: 41	Re: Press the bearing or not Rule of thumb is that a bearing is always installed with a race fastened to the part of the machine that rotates. In your case the shaft rotates so the inner race of the bearing should be a press fit onto the shaft. If the shaft is worn so that the race is a slip fit, loctite can be used to secure the bearing race to the shaft.

10-13-2011, 05:11 PM	#5
Doug in NJ Senior Member Join Date: May 2010 Location: Princeton, NJ Posts: 965	Re: Press the bearing or not I assume he was talking about the rear bearing. Doesn't that fit over splines, which might make a tight press fit problematic? I expect the front bearing to be a press fit. Doug __________________ My '31 S/W sedan project:http://31ford.dougbraun.com My restoration diary: http://dougbraun.com/blog

10-13-2011, 05:55 PM	#6
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Press the bearing or not Sponsored Links (Register now to hide all advertisements) I lay the bearing over a hundred watt light bulb for a while to heat up and expand, I then slip the bearing in place, no press needed. This method was published in one of the national club magazines many years ago and has always worked for me.

10-14-2011, 05:28 AM	#7
Wick Senior Member Join Date: May 2010 Location: Gwynn's Island Va Posts: 1,390	Re: Press the bearing or not I use a bearing heater when I can. The light bulb works well too. 220 degrees bearing temp and it will fall right on.

10-16-2011, 11:33 PM	#8
Grampy Member Join Date: May 2010 Posts: 61	Re: Press the bearing or not It is the rear bearing we were talking about, and, yes it does fit over splines, which is exactly what started the conversation in the first place. Thank you guys for your comments.

10-17-2011, 08:33 AM	#9
James Rogers Senior Member Join Date: May 2010 Location: Asheville,NC Posts: 3,104	Re: Press the bearing or not Neither bearing needs to be pressed on or should not be pressed off. Either might be a tight fit but, both are held on by a clip so, pressing is not needed. The front by a cup circlip and the rear by a small standard circlip.I have never had to press one on, just some light tapping with a hammer and pipe but, some are a bear to remove.