Axle Repair Sleeves/Shims?

J

jeepguy1948

Well-known member
I just pulled a rear hub off of a new to me ‘30 and found one sleeve/shim. I think it needs more because I can see where the drum is rubbing the side of the brake shoes and there were too many washers under the nut. I have never used those shims before but I do have a good stash of them. What is the goal when using the shims? How do I know when I have enough of them installed?
 
94 year old guy in our club says that yes, you can use more than one. I would ask him my question but he is not available.
 
jeepguy1948 said:
94 year old guy in our club says that yes, you can use more than one. I would ask him my question but he is not available.
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Well I guess I would think the answer to your question would best be answered by you. What is your life worth, ...or what is your vehicle worth to you??

Using an Axle Shim changes the whole dynamics of how the Axle & Shaft are supposed to be mated. The tapers of both items are designed to be a perfect friction fit. The Axle Nut really should not require excessive torque to hold the Hub tightly onto the Axle shaft. Many people WAY overtighten these Nuts, which can (-and does) cause an Axle Shaft to break. I was just in your country and we were all coming out of Sparta, ON headed back to London when an Axle on the L/R broke right at the threaded portion. While it happened just before we got there, witnesses said the occupants were extremely lucky as the car skidded off the road without overturning. The car did not faire as well and the L/R Fender was severely mangled and there appeared to be some damage to the Quarter Panel. There laying beside the car was the Hub still attached to the Wheel, and the remnants of a mangled Axle Shim. I did take pictures of the carnage if folks need to visually see and verify.

My experiences over the years are that when an Axle breaks at the end of the Axle Housing, it is caused by a worn Hub Bearing or Race that has allowed the Axle to be scored by rubbing on the Housing. When the Axle breaks at the threads, that is the result of over-tightening the Axle Nut as the mechanic is trying to make the Hub fit tighter. Generally speaking, the looseness is because the taper of the Shaft and/or the taper in the Hub are damaged, ...and if an Axle Shim is needed, then the two tapers are excessively worn to the point where they are never going to friction-fit as they were designed. Using one Shim will never allow the Hub to truly be tight, and using two Shims only exacerbates that problem.

Again, it is your vehicle and life, so do as you wish however it is my opinion that your life, nor the life of others is not worth the risk of using a Shim as a way to patch a problem.
 
Brent, would you say that the axle nut in this joint is performing a similar function as the drawbar on a milling machine? In other words that it is maintaining the friction fit by preventing the tapered elements of the joint from separating?

There’s often confusion in this forum about how torque is transmitted in the rear axle joint. In a machine taper system, torque is transmitted through friction between the tapered surfaces. Like the rear axle, taper-fit tools often have a key and a threaded section, which engages the drawbar. However these are not intended to transmit torque themselves but rather to hold the friction fit joint in place.

Needless to say, if torque is being transmitted through friction between the tapered surfaces, adding two flexible shims between those surfaces would make a friction fit impossible.
 
alexiskai said:
Brent, would you say that the axle nut in this joint is performing a similar function as the drawbar on a milling machine? In other words that it is maintaining the friction fit by preventing the tapered elements of the joint from separating?

There’s often confusion in this forum about how torque is transmitted in the rear axle joint. In a machine taper system, torque is transmitted through friction between the tapered surfaces. Like the rear axle, taper-fit tools often have a key and a threaded section, which engages the drawbar. However these are not intended to transmit torque themselves but rather to hold the friction fit joint in place.

Needless to say, if torque is being transmitted through friction between the tapered surfaces, adding two flexible shims between those surfaces would make a friction fit impossible.
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Yes, and Yes.
 
The shims come in various thicknesses. I've used them for years with no problems. Occasionally they have to be replaced.
 
jeepguy1948 said:
I just pulled a rear hub off of a new to me ‘30 and found one sleeve/shim. I think it needs more because I can see where the drum is rubbing the side of the brake shoes and there were too many washers under the nut. I have never used those shims before but I do have a good stash of them. What is the goal when using the shims? How do I know when I have enough of them installed?
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Things to check before using tapered shims:

1. Is the side of the service brake shoes rubbing on drum?

OR

2. Is the SIDE of "parking brake" BAND rubbing on drum?

Two different problems with totally different causes.

1. If service brake shoes are rubbing then taper on axle OR ID of the hub may be worn OR both.


2. If the side of the parking brake BAND is rubbing then it is possible that someone has installed brake BAND backwards with Outside of band pointing Inside). If backwards the band will sit crooked on backing plate so it will not sit FLAT against the backing plate. The drum will not go on all the way and will make it appear that the hub needs to be shimmed.
 
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Remember, when assembling the hub to the axle, with or without shim(s), that it must all be perfectly clean and dry, no oil, grease or other contaminate.
 
Hello, some of those axle tapers are in bad shape after 90 plus years of use and abuse, the shims are only a temporary fix, best to replace axle and hub for reliability,however I have read on some of the repro axles, problems with the welding of gear onto axle shafts according to older Ford Barn posts.
 
Brent said : "My experiences over the years are that when an Axle breaks at the end of the Axle Housing, it is caused by a worn Hub Bearing or Race that has allowed the Axle to be scored by rubbing on the Housing."
I have posted about that before but I would add that even if the axle does not touch the end of the housing, it is going to break just inboard of the hub if the hub is worn.
 
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