rear axle nut torque

It is high, very high like around 200 ft lbs. I never try to take it up that high in 1 pull. I tighten it up pretty tight, (leave cotter pin out) drive around the block, tighten again. I do that a couple of times to work the hub onto the taper. Then when it is REALLY tight, I put a torque wrench on it and take it to 195 ft lbs and then the next cotter hole and install cotter.
It is the friction of the taper of the axle and the hub that keeps the hub from spinning on the axle NOT the key. If the hub is loose enough that the axle key is driving the car, you will eventually brake the end off the axel as a crack will develop at the inner end of the axle key recess.
 
it is high, very high like around 200 ft lbs. I never try to take it up that high in 1 pull. I tighten it up pretty tight, (leave cotter pin out) drive around the block, tighten again. I do that a couple of times to work the hub onto the taper. Then when it is really tight, i put a torque wrench on it and take it to 195 ft lbs and then the next cotter hole and install cotter.
It is the friction of the taper of the axle and the hub that keeps the hub from spinning on the axle not the key. If the hub is loose enough that the axle key is driving the car, you will eventually brake the end off the axel as a crack will develop at the inner end of the axle key recess.

perfect (accurate) advice.
 
Thanks Mike!
I forgot to mention that I also take a sharpie and draw a line on the end of the axle so I know where the cotter hole is located.
 
Thanks Mike!
I forgot to mention that I also take a sharpie and draw a line on the end of the axle so I know where the cotter hole is located.

Reminds me of when I owned a 1966 Big Block Corvette with real knock-off wheels. If not torqued right they would come off the car at speed! Needless to say I was a perfectionist at setting to torque specs and then adding safety tape to each spinner to watch for any movement. Every time I went for a ride I would perform a "preflight" inspection to monitor those wheels! Never had a mishap!
 
After I had to change an axle since the threads stripped, i spent a bunch of time cleaning the surfaces and lapping the axle to the drum to ensure a good fit.
I also fabbed up a set of drum retainers in case the axle ever breaks.
 
I've been through the axle torque issue. There are differing views. I''m passing on this one from a FB member given to me as "just his opinion" & I choose not to identify him. I think his view has a lot of credibility, however. Here it is:



I would think the purpose of the initial torque which seems to be very high, is to set the axle and hub tapers tight enough to keep them together. Once this has been accomplished, a lesser torque value would be sufficient to keep the hub from loosening on the axle. After the cotter key has been placed the nut is not going to move whether the torque is 225 or 125. I would go back to the super clean fitment between axle and hub tapers and their exact angle degrees to be of the utmost importance. Do not take any of this to the bank! Just my thoughts at this time
 
Update. Cleaned axle threads a bit using Blue Point tool. Then, using correct 5/8” - 18 good used Ford nuts obtained from unidentified source, was able to torque both rear drums to 175 FPs. As suggested by John (JM 35 Sedan), will drive the car a bit, then add 10 FPs repeating until I reach 200. Thanks again to everybody for your input.

psogden, just wondering if you have taken the axle nut torque on your car any higher than 175 ft lbs?
 
Ford Model A Rear Axle Specifications
Type: Three Quarter Floating

Material: Special Ford Carbon Manganese Steel

Gear Ratios:

3.78:1
3.70:1 (early 28’s)
3.54:1
4.11:1
Bearings:

Rear Wheel:
O.D. of Axle Housing Race – 2.061″ to 2.0635″
I.D. of Wheel Hub 3.188″ to 3.190″ – Max Wear 3.185″
Pinion Bearing:
Timken 28156 (2 each) – Double Taper Roller Type
Bearing Cup: Timken 28317
Ring Gear:

8.4″ Pitch Diameter
1 3/16″ Wide Teeth
Axle Shaft:

1 1/8″ Diameter
1.128″-1.130″ at Wheel Bearing
Dimension From Housing Flange to bearing Shoulder in Axle Housing:

Before 1929: 1.370″ to 1.372″
After: 1.365″ to 1.367″
Axle and Drive Shaft Seal: CR 10926

Rear Axle Seal: CR 20112, Victor 49024

Differential Lube: 600W to 160W

Differential Oil Capacity: 2 1/4 Pint

Torque Specs:

Axle Nut Torque: 100 ft/lbs
 
I'm not going to say that is wrong but I believe it should be much higher than 100 ft/lbs.
 
As a teen I remember it well ! NO brakes at ALL - FOOT PEDAL WEMT TO THE F;OOR -- EMERGENCY ALL THE WAY UP. - SHUT OFF AND WAITED FOR IT TO STOP !! I was lucky - no traffic and just to go, pick up the fender skirt . Car resting on the tire on the fender bead !! Car was a 48 Mercury Convertible. kerk
 
I just picked up a 50-250# torque wrench to do the wheelbearing on my brothers 08 chevy truck. Torque was like 200plus. Wrench wasn't cheap but if a shop did the wheelbearings it would have cost a few hundred past that.

Story not really helpful here but,... I do think most places like autozone lend tools out for free. Torque wrenches included.


Link lifted from the Model A forum right here on the barn. Model A Ford 100-125#

https://www.fordbarn.com/forum/showthread.php?t=257654&highlight=rear+axle+nut+torque



.
 
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Take a look at a the torque value chart, even a grade #2 5/8-18 bolt/nut recommend torque value dry is 115 ft-lbs. And Ford axles are not grade #2 equivalent by a long shot.

Torque Values (dry) for:

Grade #5 bolt/nut - 180 ft-lbs
Grade #7 bolt/nut - 210 ft-lbs
Grade #8 bolt/nut - 240 ft-lbs

Ford axles and axle nuts are high quality/grade parts.
 

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For me, 100-125 lbs/ft isn't tight enough for a V8 axle.

200-220 lbs/ft according to Service Letter mentioned in an old V-8 Times; then follow duece roadster's advice... do not exceed 275 lbs/ft when lining up for the cotter pin.
 
Let me tell you a little story about the pre 48 axle nuts.

When I was 18 (1963), my best friend had a 32, chopped and channeled, 5 window coupe, with a 326 CI Olds and a 4-71 blower on top of it. It had a 37 LaSalle trans and a 4500# Hays clutch connected to the rear axle.

We were street racers and after George got the blower, almost every race, we would shear a key. After the 3rd key, we put a 4 ft, pipe wrench on that nut. I can't tell you how much torque, a 150 lb kid put on the nut (150x4ft = 600 ft #, I'd say at least 350 ft#) but, the nut and threads did not strip. At the very next race, the key stayed but, we broke the axle!!!

This picture is after that. We put a Olds rear end and 4 speed hydro behind it.
 

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250 ft. Lbs. And back off until you can insert the cotter pin. Make sure the fine threads are clean and good.
 
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