The Ford Barn

Russell Reay · 09-01-2021, 08:55 AM

Just discovered a shim on the left axle, so there is one on each side. Since the hub does not rotate on the axle, how can there be enough hub to axle abrasion to cause wear?

katy · 09-01-2021, 10:12 AM

Caused by the vehicle being driven w/out the nut being properly tightened enough.

WHN · 09-01-2021, 10:45 AM

Quote:

Originally Posted by katy

Caused by the vehicle being driven w/out the nut being properly tightened enough.

Needs to be torqued to at least 100. Common problem.

Enjoy.

Fullraceflathead · 09-01-2021, 10:46 AM

You can try removing the shim and reinstalling the hub to see if the brake drum rubs the backing plate most likely it does rub and that is why the shim was installed.

nkaminar · 09-01-2021, 08:16 PM

The axle nuts have to be tightened once a year or more depending on how much you drive the car

Bob Bidonde · 09-02-2021, 08:09 AM

Sponsored Links (Register now to hide all advertisements)

Some reverse engineering shows this is how the rear axle taper works, and the probable causes of a drum rubbing on the backing plate:

Russell Reay · 09-02-2021, 08:29 AM

Quote:

Originally Posted by Bob Bidonde

Some reverse engineering shows this is how the rear axle taper works, and the probable causes of a drum rubbing on the backing plate:

Good explanation, but can't help noting conflicting info. Others have declared that the torque is transmitted from the tight fit of the hub to the axle, and NOT the key. Also, you recommend torqueing nut to 50 lbs, whereas almost all others recommend 100 lbs. New hub is on order.

Bob Bidonde · 09-02-2021, 08:43 AM

Take the key out of the right rear axle hub and attempt to drive the car on the friction fit of the taper alone. Let me know how far the car goes. As for the torque value, the higher the torque, the higher hoop stress in the hub goes. At 100 lbs-ft of torque on the nut, I think the hub is yielding. I doubt that the factory assembly-line worker torque the nut to 100 lbs-ft. That's a 100 lb force on a 1-foot long wrench!

WHN · 09-02-2021, 10:57 AM

Without the key, or with a broken key the car will stop moving. However, the key being there is not the only reason the car moves. The key along with the torque on axel tapper is how it was designed to work. A loose hub will ware both the axel end and eventually break the key. Causing the axel to spin within the hub.

A properly torqued axel without a key will move the car. How long? You need both for it to work properly. 100 foot pounds is the right figure. Not my first rodeo with this problem.

Enjoy.

Russell Reay · 09-02-2021, 12:01 PM

Not looking to provoke an argument here, just seeking best info and guidance from those who have lots more experience than me--that's everyone. I cannot possibly imagine working on a Model A w/o the participants on this forum. Thank you a thousand times, and I'll be back for more.

john in illinois · 09-02-2021, 05:06 PM

Quote:

Originally Posted by Bob Bidonde

Take the key out of the right rear axle hub and attempt to drive the car on the friction fit of the taper alone. Let me know how far the car goes. As for the torque value, the higher the torque, the higher hoop stress in the hub goes. At 100 lbs-ft of torque on the nut, I think the hub is yielding. I doubt that the factory assembly-line worker torque the nut to 100 lbs-ft. That's a 100 lb force on a 1-foot long wrench!

This is not correct. I hope the new A owners on the forum reallize this.

John

09-01-2021, 08:55 AM	#1
Russell Reay Senior Member Join Date: May 2021 Location: NH/ VT Posts: 334	Rear axle shims Just discovered a shim on the left axle, so there is one on each side. Since the hub does not rotate on the axle, how can there be enough hub to axle abrasion to cause wear?

09-01-2021, 10:12 AM	#2
katy Senior Member Join Date: Jun 2015 Location: Red Deer, Alberta Posts: 5,042	Re: Rear axle shims Caused by the vehicle being driven w/out the nut being properly tightened enough. __________________ If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn!

09-01-2021, 10:46 AM	#4
Fullraceflathead Senior Member Join Date: May 2012 Location: Chillicothe, Missouri Posts: 1,176	Re: Rear axle shims You can try removing the shim and reinstalling the hub to see if the brake drum rubs the backing plate most likely it does rub and that is why the shim was installed. __________________ "If I asked people what they wanted they would have said faster horses." -Henry Ford "Primitive technology is not a design flaw" 1928 Ford Model A Roadster Pickup 1930 Gordon Smith Air Compressor 1941 Willy's Pickup 1960 Thunderbird-For Sale 1964 Buick Riviera 2x4 425 1965 Pontiac GTO, 455 Super Duty 2004 Dodge Ram SRT-10, V-10 Viper 1977 Charger Jet Boat,460 Ford,Jacuzzi Jet Front Engine Nostalgia Dragster,Supercharged 296 "Fullrace Flathead" Ford Engine Build up on DVD ask

09-01-2021, 08:16 PM	#5
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,900	Re: Rear axle shims The axle nuts have to be tightened once a year or more depending on how much you drive the car __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

09-02-2021, 08:43 AM	#8
Bob Bidonde Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 3,464	Re: Rear axle shims Take the key out of the right rear axle hub and attempt to drive the car on the friction fit of the taper alone. Let me know how far the car goes. As for the torque value, the higher the torque, the higher hoop stress in the hub goes. At 100 lbs-ft of torque on the nut, I think the hub is yielding. I doubt that the factory assembly-line worker torque the nut to 100 lbs-ft. That's a 100 lb force on a 1-foot long wrench! __________________ Bob Bidonde

09-02-2021, 10:57 AM	#9
WHN Senior Member Join Date: Mar 2017 Location: Connecticut Shoreline Posts: 1,821	Re: Rear axle shims Without the key, or with a broken key the car will stop moving. However, the key being there is not the only reason the car moves. The key along with the torque on axel tapper is how it was designed to work. A loose hub will ware both the axel end and eventually break the key. Causing the axel to spin within the hub. A properly torqued axel without a key will move the car. How long? You need both for it to work properly. 100 foot pounds is the right figure. Not my first rodeo with this problem. Enjoy.

09-02-2021, 12:01 PM	#10
Russell Reay Senior Member Join Date: May 2021 Location: NH/ VT Posts: 334	Re: Rear axle shims Not looking to provoke an argument here, just seeking best info and guidance from those who have lots more experience than me--that's everyone. I cannot possibly imagine working on a Model A w/o the participants on this forum. Thank you a thousand times, and I'll be back for more.