The Ford Barn

Milt K from Pa · 05-10-2011, 02:54 PM

Barners,
I have been unable to find torque specs for the bolts holding both axle housings to the center banjo housing on my '34. These are the 10 on each side bolts. Anyone have Fords spec, rather than standard max torques set up for 3/8-24 bolts?
Thanx
Milt K from Pa

PeteVS · 05-10-2011, 03:03 PM

I thought Ford didn't specify torques back in the day, buy Bratton's shows 35 foot pounds. I'd say that using a standard torque for the bolt size should be safe if it differs from the above. One thing you don't want to do is chase the holes in the pumpkin casting with a tap. That's supposed to be a snug fit of the bolt in the tapped hole to reduce leakage of the lube out through the threads. Might want to put some mild LocTite on them to help seal.

Milt K from Pa · 05-10-2011, 03:18 PM

Pete, thanx for the reply. After finishing the process of shimming the two housings, the threads are lose as it is. I will be using a sealant. I guess the standard torque will have to do.
Milt K from Pa

rotorwrench · 05-10-2011, 03:40 PM

The old Ford manuals state to install an assembly and "secure the bolts". Later maintenance manuals gave special torque specs at the end of the applicable chapter and that was as good as it got. Standard torques depend on the type of fasteners used. In aviation, there are AN standards for bolts but very few use National Course thread. The chart I use for standard torques is from an old Hughes Helicopters 269 series maintenance manual. The 3/8-24 threaded bolts with tension type nuts calls out 160 to 190 Inch/Lbs with a max tourque of 390 In/Lbs. This translates to 14 to 16 Ft/Lbs with a 32 Ft/Lb Max torque. On shear type applications where the fastener is not under tension, the torque is much less. 3/8-24 is 95 to 110 In/Lbs with a max of 240 In/Lbs. Translation in Ft/Lbs is 8 to 9 Ft/Lbs with a max of 20 Ft/Lbs.

I've used this chart for years and never had a problem with the Ford fasteners. I would use the tension specs for a housing that is under both tension and shear.

Kerby

Bruce Lancaster · 05-11-2011, 09:21 AM

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Origianally in the overhaul instructions the only torque spec given was the preload on the pinion...that changed from a very subjective description to an actual inch-pound number maybe '32 or '33. Different numbers for the different generations of the Banjo of course. They released numbers for the axle end nuts near the end of early Ford times, too.
There are good procedures for the different models in Model A bulletins updated in '32 bulletins, 1933 bulletins for that rear, and about 1938 to cover the later group.

05-10-2011, 02:54 PM	#1
Milt K from Pa Senior Member Join Date: May 2010 Location: Pittsburgh Pa. Area Posts: 272	Rear end bolts Barners, I have been unable to find torque specs for the bolts holding both axle housings to the center banjo housing on my '34. These are the 10 on each side bolts. Anyone have Fords spec, rather than standard max torques set up for 3/8-24 bolts? Thanx Milt K from Pa

05-10-2011, 03:03 PM	#2
PeteVS Senior Member Join Date: May 2010 Location: FP, NJ Posts: 2,811	Re: Rear end bolts I thought Ford didn't specify torques back in the day, buy Bratton's shows 35 foot pounds. I'd say that using a standard torque for the bolt size should be safe if it differs from the above. One thing you don't want to do is chase the holes in the pumpkin casting with a tap. That's supposed to be a snug fit of the bolt in the tapped hole to reduce leakage of the lube out through the threads. Might want to put some mild LocTite on them to help seal. __________________ Don't never get rid of nuthin!

05-10-2011, 03:18 PM	#3
Milt K from Pa Senior Member Join Date: May 2010 Location: Pittsburgh Pa. Area Posts: 272	Re: Rear end bolts Pete, thanx for the reply. After finishing the process of shimming the two housings, the threads are lose as it is. I will be using a sealant. I guess the standard torque will have to do. Milt K from Pa

05-10-2011, 03:40 PM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: Rear end bolts The old Ford manuals state to install an assembly and "secure the bolts". Later maintenance manuals gave special torque specs at the end of the applicable chapter and that was as good as it got. Standard torques depend on the type of fasteners used. In aviation, there are AN standards for bolts but very few use National Course thread. The chart I use for standard torques is from an old Hughes Helicopters 269 series maintenance manual. The 3/8-24 threaded bolts with tension type nuts calls out 160 to 190 Inch/Lbs with a max tourque of 390 In/Lbs. This translates to 14 to 16 Ft/Lbs with a 32 Ft/Lb Max torque. On shear type applications where the fastener is not under tension, the torque is much less. 3/8-24 is 95 to 110 In/Lbs with a max of 240 In/Lbs. Translation in Ft/Lbs is 8 to 9 Ft/Lbs with a max of 20 Ft/Lbs. I've used this chart for years and never had a problem with the Ford fasteners. I would use the tension specs for a housing that is under both tension and shear. Kerby

05-11-2011, 09:21 AM	#5
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: Rear end bolts Sponsored Links (Register now to hide all advertisements) Origianally in the overhaul instructions the only torque spec given was the preload on the pinion...that changed from a very subjective description to an actual inch-pound number maybe '32 or '33. Different numbers for the different generations of the Banjo of course. They released numbers for the axle end nuts near the end of early Ford times, too. There are good procedures for the different models in Model A bulletins updated in '32 bulletins, 1933 bulletins for that rear, and about 1938 to cover the later group.