Rear axle/hub nut torque

Kustom Komet

Kustom Komet

Member
I am servicing the brakes and installing Snyder's shock brackets on my '28, and I have a question regarding the torque spec on the rear axle nut. It is 125 lb/ft per the Les Andrews book.

The right side was quite tight, and the hub was tough to pull. The left side was comparatively loose; the nut was just beyond finger tight and the hub came off almost by hand. There didn't seem to be any ill-effects driving it around like that, no damage or looseness at the taper.

I did the right side about a month ago to rebuilt the wheel cylinder, and torqued it per specs. That seemed too tight for a nut with threads that size, and it didn't "feel right" to do it, like I was risking stripping the axle threads. I don't want to take them down that tight, can I just get away with 75-80 pounds instead?
 
I don't have the spec handy (search archives) but I believe I remember it being over 200 ft-lbs. The hub is supposed to be tough to pull even with the correct puller. The KR Wilson puller is generally touted to be the best. The "ill effects" may be the start of a crack that will at some time in the future cause the axle to fail. When the axle fails (without any retaining clips/safety hubs) the hub, drum and wheel can come off of the car. It can go down hill rapidly from there depending upon where you area at the time. Considering the potential damage I would very strongly consider the retaining clips to hold the brake drums/hubs on after having run with the nut that loose. Am I an alarmist, probably? Can it happen, maybe? Would I risk it, definitely not?

You said "with a nut that size". Did someone turn the axle down to smaller size? I would use the correct hardened nuts on the axle maybe from Roy Nacewicz Parts, (734) 654-9450, fordbolts.com. They are not the bolts from "Home Depot".

Charlie Stephens
 
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Kustom Komet,

Make sure you have original castle nuts, they are special hard 5/8 castle nuts and will take the torque without damaging the threads.

I torque mine to 90 pounds and then just enough to line up the cotter hole.

I have had no problem with lose rear drums.

Good luck,

Ron
 
Kustom Komet said:
I am servicing the brakes and installing Snyder's shock brackets on my '28, and I have a question regarding the torque spec on the rear axle nut. It is 125 lb/ft per the Les Andrews book.

The right side was quite tight, and the hub was tough to pull. The left side was comparatively loose; the nut was just beyond finger tight and the hub came off almost by hand. There didn't seem to be any ill-effects driving it around like that, no damage or looseness at the taper.

I did the right side about a month ago to rebuilt the wheel cylinder, and torqued it per specs. That seemed too tight for a nut with threads that size, and it didn't "feel right" to do it, like I was risking stripping the axle threads. I don't want to take them down that tight, can I just get away with 75-80 pounds instead?
Click to expand...

You will know what ill effects/damage that has been done, but 'hand tight' rear axle nut, when you find that the axle, bearing, axle key, hub, etc.... has been damaged. Damage will result in either catastrophic failure while driving...or big hit to your time and money spent correcting that damage.
Correct rear axle nut torque and WHY NECESSARY, has been discussed often here. Look up and read past threads to get lots of answers. Good luck :)
 
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Thanks for the replies and advise.

But it happened, the right thread stripped at around 70 pounds. Nut fine, the threads were weak as I suspected. Phooey.
 
Kustom Komet said:
Thanks for the replies and advise.

But it happened, the right thread stripped at around 70 pounds. Nut fine, the threads were weak as I suspected. Phooey.
Click to expand...
Better now than later. Had someone turned the axle for smaller threads or were the threads bad?

Charlie Stephens
 
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Kustom Komet,

Someone must have used a butter nut instead of a hardened original one, it screws up the threads. If you have a correct tap you might try dressing up the threads ? The threads are 5/8 x 18 . I am not a machinest so do not know if it will solve your problem ?

Ron
h
 
I hand file one down to 9/16 using a drill hole guide as a template then retreaded. The car is still on the road. I take mine to 100 then line up the slots. If they are too far off I swap nuts or remove a tiny bit from the back of the nut.
All caps on this;
DO NOT FORGET TO CHECK TO MAKE SURE THE NUTS ARE TIGHT AFTER DRIVING SOME. CHANCES ARE THEY WILL BE A LITTLE LOOSE.
 
Kustom Komet said:
Thanks for the replies and advise.

But it happened, the right thread stripped at around 70 pounds. Nut fine, the threads were weak as I suspected. Phooey.
Click to expand...
I am not sure I understand what you are trying to say. Is the nut fine except the threads stripped or did the threads on the axle strip?

Charlie Stephens
 
Ooopps, thats too bad. Some have had good luck rethreading to 9/16" as mentioned. That nut needs to be tight. The strain is taken by the taper, the strain should not be allowed to be taken by the key.
 
After brake overhaul and 1,000 miles key broke on drivers side. Both rear nuts were just hand tight. We now torque to 95-100 pounds.

I am now one of the check your axel nuts torque regularly guys. Enjoy.
 
Charlie Stephens said:
Better now than later. Had someone turned the axle for smaller threads or were the threads bad?

Charlie Stephens
Click to expand...

Original size, axle threads bad.

Ron in Quincy said:
Kustom Komet,

Someone must have used a butter nut instead of a hardened original one, it screws up the threads. If you have a correct tap you might try dressing up the threads ? The threads are 5/8 x 18 . I am not a machinest so do not know if it will solve your problem ?

Ron
h
Click to expand...

Not a shiny hardware store nut, a dark oxided nut with the tall castle tips for max thread engagement. Looks old, original or correct application to me, but then I'm a greenhorn.

redmodelt said:
I hand file one down to 9/16 using a drill hole guide as a template then retreaded. The car is still on the road. I take mine to 100 then line up the slots. If they are too far off I swap nuts or remove a tiny bit from the back of the nut.
All caps on this;
DO NOT FORGET TO CHECK TO MAKE SURE THE NUTS ARE TIGHT AFTER DRIVING SOME. CHANCES ARE THEY WILL BE A LITTLE LOOSE.
Click to expand...

This is the route I'll go here, as I really don't want to remove the whole axle and take it apart, not just yet any way. Are you saying that the axle nuts get a little loose after driving, even with the cotter pins installed?

Charlie Stephens said:
I am not sure I understand what you are trying to say. Is the nut fine except the threads stripped or did the threads on the axle strip?

Charlie Stephens
Click to expand...

Sorry, the axle threads are stripped, the nut threads are fine. They are kind of rounded, and look like they have been heading in that direction for some time. Understandable though, 90 year old axle and that nut has been torqued how many times?

Patrick L. said:
Ooopps, thats too bad. Some have had good luck rethreading to 9/16" as mentioned. That nut needs to be tight. The strain is taken by the taper, the strain should not be allowed to be taken by the key.
Click to expand...

I'm doing this, using the great Youtube videos by Fullraceflathead, already bought the 9/16-18 die and spent an hour trying to find a 1-7/16 die wrench. No luck, several stores sell the big dies but not the die handle? Is this what hell is like?

WHN said:
After brake overhaul and 1,000 miles key broke on drivers side. Both rear nuts were just hand tight. We now torque to 95-100 pounds.

I am now one of the check your axel nuts torque regularly guys. Enjoy.
Click to expand...

Roger!
 
Years ago I bought a 28 roadster that had been restored by a "professional" restoration shop. The car was beautiful. When I got to checking things over I found that both rear axle nuts had been installed finger tight as would the front axle nuts.

My routine is to set my torque wrench to 90 ft. lbs. and tighten until it clicks, then look to see where the cotter pin hole is. If it is in the window, I leave it. If not, I tighten it more until it is.

Tom Endy
 
Hey Roger,
By your responses, I'm not sure that you get how the mechanism should work regarding the rear axle, the hub, the key and cotter pin.
Check out the idea of LAPPING the axle to the hub...for a perfect fit. This is how a properly installed hub/axle relationship is formed, and how the hub stays fastened to the axle when torqued sufficiently. The key is not for holding the hub from turning, although it will do this duty for a short while , until something snaps if not torqued correctly.
 
Are you saying that the axle nuts get a little loose after driving, even with the cotter pins installed?

No, the nut won't move but the hub will creep toward the differential until it finds a home. If allowed to run loose, it will wear the hub and key way. Check it at 50 mile intervals until the nut stops tightening while using proper torque settings.
 
Are you saying that the axle nuts get a little loose after driving, even with the cotter pins installed?

What Dollar Bill said^
We have had a number of car in the shop that I bet the nut was tight when put back together by the last person working on them but after a few or more miles driving, the nuts were easy to remove after the hub took it seat. Even a Model T at 20HP can still have the same issue.
 
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