The Ford Barn

Ed in Maine · 08-22-2023, 06:46 PM

Today I pressed in the double race and inserted the drive shaft with the pinion gear and bearing into the banjo. I am having trouble installing the new forward pinion bearing. This is the bearing that should be installed with a very, very light interference fit. The old bearing does go onto skirt of the pinion gear with your fingers but the new bearing does not. Is it possible to rub the bearing and the pinion gear with crocus cloth or fine emory paper to get this bearing to slide onto the pinion gear? I can see that if this is too tight, getting a good preload will not be possible. Also, if I get the pinion gear pushed on too tightly, I may not be able to work it back off! Please comment. Thank you, Ed

lotsagas4u · 08-22-2023, 06:55 PM

Ed, maybe this will help

https://www.youtube.com/watch?v=CKVT2z2vNF4&t=794s

Tom Endy · 08-22-2023, 07:34 PM

My advice is to never pull a rear end out of a Model A with the spring attached. Use a spring spreader and leave the spring in the car where it is safely attached to the frame with two U-bolts. When out of the car attached to the rear end the only thing containing the top leaves is the 3\8" center bolt that was never meant to contain the energy packed into a spreaded rear spring even when the bot was new. If the head of the bolt, that could be 90 years old and rusted, had popped off, it would likely have broken both ankles of the guy working behind it when the spring exploded.

Tom Endy

Ed in Maine · 08-23-2023, 06:32 AM

Hello Tom, it was your advice that made me leave the spring contained by the rear spring shackles. Now when I have to mess with the spreader, I just stay away from all areas below the spring. Thanks for your input, Ed

Gary WA · 08-23-2023, 08:54 AM

http://www.santaanitaas.org/wp-conte...vised-2014.pdf thanks to supplier

Will N · 08-23-2023, 09:44 AM

Sponsored Links (Register now to hide all advertisements)

When I helped rebuild a rear end, we installed that bearing race by chilling it in dry ice so it would contract, and we heated the housing to make it expand. Went in easily.

Tom Endy · 08-23-2023, 10:25 AM

I have a cottage industry rebuilding rear axle assemblies and have been doing them for the past 35 years. There are a number of articles about the process under my name on the web site of the Santa Anita A's of Arcadia, California. www.santaanitaas.org.

Attached is one we did in 2019.

https://www.santaanitaas.org/wp-cont...-9-2019_LB.pdf

Tom Endy

Bruce of MN · 08-23-2023, 01:37 PM

The steps that the factory took to set up the rear ends would be interesting; did they have special tools and gauges that streamlined the process?

rotorwrench · 08-23-2023, 03:23 PM

It was a common practice for Ford to utilize special tooling to assemble the various components. Anything to speed up and simplify the assembly process.

If a new pinion tapered bearing cone is a tight fit on an OEM pinion then the inner race of the cone doesn't match the original Ford part dimension. They were a snug fit but could be pushed on by hand. New Timken bearings is as close to OEM as person can get. I wouldn't hesitate to use some abrasive on the stub portion of the pinion but only enough to start the bearing on. A person can do the temperature differential to assemble. I'd measure the shaft and the race. The fit should be close to a zero fit. If it is .001" tight fit then I'd be concerned that the shaft threads on the pinion may be damaged during torque up. It needs to move so it can't be too tight.

I never heat a new bearing more than 250* F for a temperature differential assembly. Freeze the part as cold as possible in a freezer or with dry ice.

Tom Endy · 08-23-2023, 03:43 PM

The original pinion gear sleeves are machined to two different dimensions. The bearing that fits on closest to the gear presses on with an interference press fit. The second bearing slides on with a little more than a hand push on. The difference in dimension is .0015. The reason for this is so that it can be easily manipulated when setting the bearing pre-load. If you get the bearings too tight it is an easy task to loosen the nuts and tap the outer bearing back and start over.

For many years reproduction pinion gear sleeves were machined to the same interference fit dimensions and it made it difficult to set the pre-load. A number of years ago Bratton's was having R&P sets made locally and they were machined correctly. However, the company went out of business a few years ago and all reverted back to square one.

Most R&P sets sold today are made in Italy and they are good quality, except the sleeve is machined to the interference fit dimension.

I have a tool I made from a discarded axle that slips into the pinion gear and can be chucked up into a lathe or a drill press to machine or file some material off the outer portion of the sleeve to make for a slip fit of the outer bearing.

Tom Endy

Grier · 08-23-2023, 10:00 PM

I just went through this with the Italian made pinion and you do need to reduce the press fit in the area for the forward second bearing. I started with Emory cloth and quickly decided this would take for ever to take 0.0015 off the diameter. You have to get the diameter down to a very slight slide fit. Which means you need to take that 0.0015 interference away. I did this with a sisal buffing wheel on my stand alone buffing motor and used either stainless steel polishing/cutting compound or rouge applied to the sisal buffing wheel. Rubbing away, rotating the pinion only where the second bearing would sit. It didn’t really take much time to do. But you have to mic or use vernier calipers during this process so that you don’t over shoot and test the fit numerous times until you are satisfied. Of course there might be a better setup to do this or take it to a machine shop, but I was successful with my method and it didn’t cost me anything except some rubbing compound.

rotorwrench · 08-24-2023, 02:47 PM

It would take a while to remove even .0015" from a pinion quill by hand. If a person has a stub shaft or a cut off end of an old drive shaft, that could be used as an arbor to chuck it into a lathe. A quick finish cut in the affected area of the bearing stub would do the trick and should keep it concentric. The manufacturers should be told to do this by the parts sources that order these parts in bulk from the manufacturer. A part should be finished when offered for sale.

08-22-2023, 06:46 PM	#1
Ed in Maine Senior Member Join Date: May 2010 Location: Washington Cty., ME or Flagler Cty., FL Posts: 1,106	31 Rear Axle Rebuild, Forward Pinion Bearing Today I pressed in the double race and inserted the drive shaft with the pinion gear and bearing into the banjo. I am having trouble installing the new forward pinion bearing. This is the bearing that should be installed with a very, very light interference fit. The old bearing does go onto skirt of the pinion gear with your fingers but the new bearing does not. Is it possible to rub the bearing and the pinion gear with crocus cloth or fine emory paper to get this bearing to slide onto the pinion gear? I can see that if this is too tight, getting a good preload will not be possible. Also, if I get the pinion gear pushed on too tightly, I may not be able to work it back off! Please comment. Thank you, Ed

08-22-2023, 06:55 PM	#2
lotsagas4u Senior Member Join Date: Apr 2011 Location: Plainview, Texas Posts: 757	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing Ed, maybe this will help https://www.youtube.com/watch?v=CKVT2z2vNF4&t=794s

08-22-2023, 07:34 PM	#3
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing My advice is to never pull a rear end out of a Model A with the spring attached. Use a spring spreader and leave the spring in the car where it is safely attached to the frame with two U-bolts. When out of the car attached to the rear end the only thing containing the top leaves is the 3\8" center bolt that was never meant to contain the energy packed into a spreaded rear spring even when the bot was new. If the head of the bolt, that could be 90 years old and rusted, had popped off, it would likely have broken both ankles of the guy working behind it when the spring exploded. Tom Endy

08-23-2023, 06:32 AM	#4
Ed in Maine Senior Member Join Date: May 2010 Location: Washington Cty., ME or Flagler Cty., FL Posts: 1,106	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing Hello Tom, it was your advice that made me leave the spring contained by the rear spring shackles. Now when I have to mess with the spreader, I just stay away from all areas below the spring. Thanks for your input, Ed

08-23-2023, 08:54 AM	#5
Gary WA Senior Member Join Date: May 2010 Location: Clinton,WA/Whidbey Island Posts: 4,105	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing http://www.santaanitaas.org/wp-conte...vised-2014.pdf thanks to supplier __________________ www.whidbeymodelaclub.com

08-23-2023, 09:44 AM	#6
Will N Senior Member Join Date: Jul 2010 Location: Pennsylvania Posts: 1,100	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing Sponsored Links (Register now to hide all advertisements) When I helped rebuild a rear end, we installed that bearing race by chilling it in dry ice so it would contract, and we heated the housing to make it expand. Went in easily.

08-23-2023, 10:25 AM	#7
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing I have a cottage industry rebuilding rear axle assemblies and have been doing them for the past 35 years. There are a number of articles about the process under my name on the web site of the Santa Anita A's of Arcadia, California. www.santaanitaas.org. Attached is one we did in 2019. https://www.santaanitaas.org/wp-cont...-9-2019_LB.pdf Tom Endy

08-23-2023, 01:37 PM	#8
Bruce of MN Senior Member Join Date: May 2010 Location: VA Posts: 1,411	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing The steps that the factory took to set up the rear ends would be interesting; did they have special tools and gauges that streamlined the process?

08-23-2023, 03:23 PM	#9
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing It was a common practice for Ford to utilize special tooling to assemble the various components. Anything to speed up and simplify the assembly process. If a new pinion tapered bearing cone is a tight fit on an OEM pinion then the inner race of the cone doesn't match the original Ford part dimension. They were a snug fit but could be pushed on by hand. New Timken bearings is as close to OEM as person can get. I wouldn't hesitate to use some abrasive on the stub portion of the pinion but only enough to start the bearing on. A person can do the temperature differential to assemble. I'd measure the shaft and the race. The fit should be close to a zero fit. If it is .001" tight fit then I'd be concerned that the shaft threads on the pinion may be damaged during torque up. It needs to move so it can't be too tight. I never heat a new bearing more than 250* F for a temperature differential assembly. Freeze the part as cold as possible in a freezer or with dry ice. Last edited by rotorwrench; 08-23-2023 at 03:32 PM.

08-23-2023, 03:43 PM	#10
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing The original pinion gear sleeves are machined to two different dimensions. The bearing that fits on closest to the gear presses on with an interference press fit. The second bearing slides on with a little more than a hand push on. The difference in dimension is .0015. The reason for this is so that it can be easily manipulated when setting the bearing pre-load. If you get the bearings too tight it is an easy task to loosen the nuts and tap the outer bearing back and start over. For many years reproduction pinion gear sleeves were machined to the same interference fit dimensions and it made it difficult to set the pre-load. A number of years ago Bratton's was having R&P sets made locally and they were machined correctly. However, the company went out of business a few years ago and all reverted back to square one. Most R&P sets sold today are made in Italy and they are good quality, except the sleeve is machined to the interference fit dimension. I have a tool I made from a discarded axle that slips into the pinion gear and can be chucked up into a lathe or a drill press to machine or file some material off the outer portion of the sleeve to make for a slip fit of the outer bearing. Tom Endy

08-23-2023, 10:00 PM	#11
Grier Member Join Date: May 2017 Location: Topsail Beach, NC Posts: 40	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing I just went through this with the Italian made pinion and you do need to reduce the press fit in the area for the forward second bearing. I started with Emory cloth and quickly decided this would take for ever to take 0.0015 off the diameter. You have to get the diameter down to a very slight slide fit. Which means you need to take that 0.0015 interference away. I did this with a sisal buffing wheel on my stand alone buffing motor and used either stainless steel polishing/cutting compound or rouge applied to the sisal buffing wheel. Rubbing away, rotating the pinion only where the second bearing would sit. It didn’t really take much time to do. But you have to mic or use vernier calipers during this process so that you don’t over shoot and test the fit numerous times until you are satisfied. Of course there might be a better setup to do this or take it to a machine shop, but I was successful with my method and it didn’t cost me anything except some rubbing compound. Last edited by Grier; 08-23-2023 at 10:05 PM.

08-24-2023, 02:47 PM	#12
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: 31 Rear Axle Rebuild, Forward Pinion Bearing It would take a while to remove even .0015" from a pinion quill by hand. If a person has a stub shaft or a cut off end of an old drive shaft, that could be used as an arbor to chuck it into a lathe. A quick finish cut in the affected area of the bearing stub would do the trick and should keep it concentric. The manufacturers should be told to do this by the parts sources that order these parts in bulk from the manufacturer. A part should be finished when offered for sale.