Rear Axle stripped

marty in Ohio

marty in Ohio

Well-known member
Hey, Guys,
A friend went to torque the rear hub nut and stripped the axle. He is now trying to find a whole rearend for his '30 coupe. I told him there is a threader that you can clamp on the axle and chase the threads. He says the axle is too small and worn to accomplish this. I asked him if he is going to replace the shaft, as I know where there is a spare one in our club. He said he was told that you would have to replace both shafts and the gears in the rear as you shouldn't mix new gears and old gears. (I'm not going to tell anyone how to fix their car) Is it right that you shouldn't replace only one shaft?
Marty
 
Replacing one shaft has been done a million times. If he wants to replace everything make sure to grab all the good parts he is removing!
 
Like the fellow above says a single axle on a Model A has been replaced thousands of times, maybe millions. Another Model A myth about matched sets. Find a better original axle and use it to replace the defective one. Make sure the threads are good and the key slot is not deformed and there are no cracks around it. The gear end is not a big consideration as it is a loose fit with the spider gears.

Attached article is how to go about the task.

Tom Endy
 

Attachments

Tell him to replace the one shaft. The gear on the end of the shaft turns very slowly only enough to make up for the difference in the radius when turning a corner. Tell him to measure the thickness of the gaskets on the housing when he takes the rear end apart as they determine the adjustment for the rear end and MUST be replaced with the same thickness assuming the wear pattern is good on the ring and pinion gears. I would have both axles magna fluxed for cracks while it is apart.

Charlie Stephens
 
As Tom said it has been done millions of times. I would absolutely use this as the opportunity to inspect every part of the rear axle including bearings and axle shaft on the other side as well and replace all parts that need to be done, set clearances as per Tom's instructions or Les Andrews, your choice. If I was doing this on the road I would fix the one that needs to be done and get back. If doing in the shop I would do it as a thorough rebuild.
Larry Shepard
 
My friend just called to say that he is going to do what Curtis did. Make the shaft smaller and rethread. I think I would replace the shaft. Just saying.
Marty
 
Do the most or do the least, interesting juxtaposition. I wonder if a metric size might be a compromise for diameter?
 
marty in Ohio said:
My friend just called to say that he is going to do what Curtis did. Make the shaft smaller and rethread. I think I would replace the shaft. Just saying.
Marty
Click to expand...

Marty,
I would impress upon them not to do that. I had an axle break when I was in the smokey mountains and 3 hours later I was back on the road. I pulled the drivers side backing plate and radius included and had it done quick. I would suggest they fix the one axle as as the smaller thread diameter is risky at best with the proper torque required. Is his life not worth that much if the wheel comes off?

Fix it right! Would he travel with only two lug nuts?
It's the equivelant of that.
Larry
 
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marty in Ohio said:
My friend just called to say that he is going to do what Curtis did. Make the shaft smaller and rethread. I think I would replace the shaft. Just saying.
Marty
Click to expand...
With the torque necessary to hold the hub taper against the axle I definitely wouldn't make it smaller. If you torque it enough the axle or nut will strip. If you don't torque it enough the axle will break due to fatigue. I am not sure how you wild find the middle ground. With later Ford hydraulic brakes (does your friend have them?) you can run safety hubs or safety clips to minimize the damage. With mechanical brakes you just have the wheel/hub and drum come off of the car taking the fender and other disastrous things. TELL YOUR FRIEND TO DO IT RIGHT!!!

Charlie Stephens
 
Fullraceflathead said:
I made a video showing how to go down to a 9/16 thread size from the original 5/8's thread.
Its on Youtube.
Yes The Model A Ford is also a 40Horse Power Lathe!!!

https://youtu.be/lC_zIvb1Yuo?list=PLav-W1BC-Nj-T6al6Pk5bcpNJQdDfO5H8[/QUOTE

Question: Isn't it hard on the axle seal to run that axle without the hub bearing to center it and keep the load off that seal? Also, since you are using a split die, do you use the set screws in the handle to open the die a little and cut less metal to get better thread engagement with the nut? If the nut can rattle around on the axle threads, you are losing some thread strength, it would seem.
Click to expand...
 
Once the 5/8 thread is stripped you are not removing very much material per side to get to 9/16".
A sharp file cuts without much pressure. My seal didn't get harmed when I did my axle.
A Modern Die is sized to a Modern nut, there is no slop on the fit.
 
Well, To end this thread, we put an electric drill, with a socket in the chuck, and turned the axle from the right side. Friend then held the file to the left axle. Threaded the left axle to 9/16 as in the youtube that Tom Endy presented. This did the job and I think it will be fine but it still seems a little slipshod to me.
Marty
 
What did he torque the axle nut to when he put the drum back on? Remember if he is running hydraulic brakes to run safety hubs or clips.

Charlie Stephens
 
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