Safely Removing A Hub

Best practice for non-destructive removal of Ford rear tapered axle hub / drum from the axle assembly

This discussion will be limited to removing rear brake hubs with drums on early Ford cars with tapered axles, generally the period beginning with Model A's in 1928 to nearly 1950. Note: Many Ford trucks from that period do not necessarily have tapered axles.

Please remember you are dealing with cars and assemblies that are as much as 90 years old. There likely is no record of how they were stored, or where they were stored. And more importantly, what maintenance was performed before, during, and after they were stored.

Brief story with several takeaways:

Recently, a Model A being restored required the rear brake drum/hub assemblies to be removed as part of the process of restoration. The vehicle had been in storage for decades and there was no knowledge of how or when it was last serviced. This car appeared to be in very good condition with little evidence of wear seen while the driveline and chassis parts were being removed. Now the rear hub/drum removal - One rear hub came apart easily. When the hub popped free and was removed, it was clear that axle grease / oil had gotten past the axle housing seal and coated mostly everything inside the drum including the brakes. The oil and grease really facilitated the easy removal of the hub/drum for inspection and restoration. The other side was a distinctly different matter. After several hours, with great care and concern the assembly was successfully removed. It was apparent that the assembly was as dry as a bleached bone in the desert sun. No oil in the assembly made for a very stuck hub.

Several takeaways:

  1. Often you cannot tell why something is so unbearably stuck together until it is separated.
  2. Patience and persistence as opposed to frustration and force will ultimately save time, expense, and possibly irreplaceable components
  3. Oil will un-stick components just as well as it is intended to lubricate them.

Safety precautions:

  • Old brake shoes often contain asbestos (very carcinogenic), do not inhale any dust.
  • Wear safety glasses
  • Wear gloves
  • Maintain good ventilation
  • Ask for help if you get stuck or are unsure about anything.

Tools/supplies required to remove hubs:

  • Floor jack, jack stands, wheel lug nut wrench.
  • Cleaning - Solvent, wire brush, rags, drain pan.
  • Brake adjustment screw - Model A, 7/16 inch spanner, 12" brakes, 11/16".
  • Cotter pin removal - Pliers, screwdriver.
  • Castle nut removal - 15/16 inch socket/wrench.
  • Heating the hub - Propane torch.
  • Striking the hub - 4 lb. hammer plus backup hammer/sledge/anvil.
  • Penetrating oil - a superior and excellent penetrating fluid is made by using 2 oz. of ATF (automatic transmission fluid) mixed with 2 oz. of acetone. If you can, get a little 4 oz. squirt bottle with a needle tube top to hold the mixture and use as an applicator. NOTE: Acetone is a highly combustible solvent available at hardware stores. ATF available at automotive stores.
  • Torque wrench - 150 Ft.Lbs. capability. (You gotta have a torque wrench, even for a Model A - wheel lug nuts, head nuts, etc., need to be regularly checked for the proper torque.)
  • 1 1/8 inch Socket that will fit the torque wrench for the hub puller thrust bolt.
  • 1 1/8 inch spanner wrench to counter the torque wrench for hub puller thrust bolt nut.
  • Molly grease for Hub puller. The puller will last much longer with a little thread & thrust lube.
  • Most importantly - A Vintage Precision Rear Hub Puller.

Best practice: Note: Check the puller instructions for picture of parts with I.D. names.

  1. Get the car on jack stands on level ground secure and safe. The most stable place for the stands is likely under the front and rear axles. Remove the wheels.
  2. Clean away all visible grease, dirt, and crud from the hub, drum, backing plate, and protruding axle threads.
  3. Loosen the brake shoe adjustment screws to free the brake shoes from dragging as far as possible. You should be able to bang the drum and hear it ring like a bell.
  4. Remove the cotter pin from the castle nut holding the hub to the axle and remove the castle nut and washer.
  5. Clean again the protruding axle thread with solvent. Rotate the drum assembly to find the keyway and concentrate on removing any visible debris. There should be about 7/8 inch of thread sticking out from the hub face. Inspect the threads and cotter pin hole for signs of damage - The cotter pin hole not being round and/or inconsistent threads, including a change in pitch and/or diameter or looking different from beginning to end, would suggest prior removal and servicing damage. Test fit the thrust plate nut to make sure the thrust plate nut will engage 9 threads (1/2 inch) or more beyond the cotter pin hole before bottoming out. Then, remove the thrust plate nut for steps 6) thru 8). (If the thrust nut will not thread on with minimal force, see the section at the end concerning the importance of preserving the axle threads and restore the axle threads before going to the next step.)
  6. Apply penetrating oil around the axle threads and specifically into the keyway area of the axle shaft. Use the squirt bottle and work it into the keyway area. The idea is to migrate the mixture 3 inches along the keyway toward the interior of the hub. NOTE: Enclosed spaces with acetone fumes can be explosive. Use lots of ventilation and no open flame until you cannot smell the acetone anymore. Acetone will evaporate quickly, but it is a great solvent carrier for the ATF to penetrate the assembly. Use gloves, acetone will penetrate your skin just like lacquer thinner or any "hot" solvent.
  7. Use a propane torch (after the acetone fumes clear) to heat the tapered hub extension to expand the hub and draw the solvent/oil into the axle hub. The tapered section of the axle extends from the wheel bolt face to the end of the hub where the castle nut was installed. Do not heat the drum bolt face, just the hub tapered extension. Rotate the axle to uniformly heat until it is too hot to touch. This is somewhere between hot enough to make spit sizzle and smoking hot. NOT ANYWHERE near red hot. It will be the ATF that is smoking.
  8. Use a 4-pound hammer to strike the center of the tapered hub extension that was heated. The impact should be in the middle of the tapered section halfway between the castle nut seat face and the wheel bolt face. Be careful not to hit any wheel stud that is in harm's way. It is advised to use a backup hammer of approximately the same weight held firmly against the hub on the opposite side from the impact hammer. Strike in one spot 3 to 4 times, then rotate the hub in 1/5 turns and repeat the striking. 1/5 turns mean you're striking between wheel studs with less chance of bonking a stud.
  9. Reinstall the thrust plate nut on the axle to bottom it against the end of the axle or the face of the hub. Now, most importantly, TURN BACK OR UNTHREAD THE THRUST PLATE NUT ONE TURN from being bottomed. This will prevent damage to the cotter pin hole and/or first 1/4 inch of axel threads that can occur if bottomed when the load is applied.
  10. Install the half shells, thrust bolt assembly and lock cover. Hand tighten the thrust bolt to seat against the thrust plate nut. Don't forget to lubricate the thrust bolt, thrust nut, and thrust plate face with grease.
  11. You need a torque wrench that will go to 150 ft. lbs. with a 1 1/8 inch socket and another 1 1/8 inch wrench that will fit the nut of the thrust bolt assembly. Tighten the thrust bolt with the torque wrench to 145 ft. lbs. Do not exceed 150 ft. lbs. or you may damage the puller and/or axle.
  12. If it pops (can sound like a rifle shot), your hub is free. If it didn't break free, your choices are: A) leave it loaded at 150 ft. lbs. and go have breakfast, lunch, or dinner, or leave overnight before returning to see if it is free. Or B) Remove the puller and repeat numbers 6) thru 11).
  13. We also had good luck by doing all the above plus ringing the outer diameter of the brake drum with a hammer. Not so hard as to dent it, but more like ringing a bell. After 10 or 15 minutes of repeated ringing vibrations it popped, we were all smiles - mission accomplished. THE OIL LETS THINGS SLIP AND THE HEAT AND BANGING WORKS THE OIL INTO THE TAPERED AREA TO DO THE WORK.

Preserving Axle Threads

The clamping force of a lubricated 5/8-18 castle nut holding the hub to the axle is about 15,500 Lbs. when torqued to 125 Ft. Lbs. That force is distributed through ½ inch of full threads in the castle nut or 9 full clean threads.

To push the axle out of the hub, we are using a 3/4-16 bolt to push against the thrust plate nut assembly. Applying 145 Ft. Lbs. of torque to the 3/4 inch thrust bolt will give about 15,400 Lbs. of force to push the axle out of the hub. The critical desire is to make sure the force is distributed thru the thrust plate nut to a minimum of 9 full threads (1/2 inch) beyond the cotter pin hole.

Make sure the thrust plate nut will thread ½" beyond the cotter pin hole to take the force potentially required. And make sure the thrust plate nut is one turn from bottoming against either the end of the axle or hitting the hub clamp face.

Be very careful about cleaning axle threads to get the thrust plate nut to install fully. If you must clean some threads on the axle, use an 18 pitch thread file and only clean the threads from the end of the axle ¼ inch to the inward edge of the cotter pin hole and not beyond the cotter pin hole. This is because the threads always get compressed and damaged between the end of the axle threads and the cotter pin hole. Using a thread chaser will index from those first compressed threads and then shave the remaining threads to correct the pitch, which is bad. By cleaning or filing metal from the leading threads, the chaser can index on the threads you most want to preserve, the 9 plus threads after the cotter pin hole. The axle thread is 5/8-18, so the file is an 18 pitch file and the chaser is a 5/8-18 thread chaser. Don't bottom the thrust plate nut and you don't damage those first threads.

For more information on Vintage Precision's Rear Hub Puller, including updated pricing and availability, contact us by clicking here or call our customer service department at 1-800-486-0021.

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