Brake Drum - Rear

Remove and replace the rear brake drums on a 1970 AMC Rebel Machine to restore proper braking performance and enable inspection or replacement of brake shoes and hardware.

Warnings

Tools required

Parts

• Rear brake drum × 2 — 10" x 2.5" drum, AMC part 3201753 or equivalent

Preparation

1. Park vehicle on level, solid ground and place transmission in Park (automatic) or first gear (manual).
2. Place wheel chocks in front of both front wheels to prevent vehicle movement.
3. Loosen rear wheel lug nuts approximately one turn while wheels are still on the ground.
4. Raise rear of vehicle with floor jack at the rear axle differential housing.
5. Place jack stands under the rear axle tubes near the spring perches on both sides, ensuring vehicle is stable.
6. Remove rear wheels completely and set aside.
7. Ensure parking brake is fully released inside the vehicle.

Procedure

1. 1

   Inspect drum retention and prepare for removal
   Examine the brake drum center for any retaining clips, speed nuts, or sheet metal push-nuts that may have been installed during assembly. These are not always present on AMC vehicles but check carefully. If found, remove them with pliers or flathead screwdriver. Note the drum offset and orientation before removal for proper reinstallation.
2. 2

   Attempt initial drum removal
   Grasp the drum firmly with both hands and pull straight outward away from the axle hub. The drum should slide off the wheel studs and over the brake shoes. If the drum moves slightly but catches, the brake shoes may be adjusted too tightly or worn into a ridge on the drum surface.
3. 3

   Back off brake shoe adjustment if necessary
   If the drum will not clear the brake shoes, locate the brake adjustment slot on the backing plate (typically at the bottom rear). Insert a brake adjustment tool or flat screwdriver through the slot and rotate the star wheel adjuster to retract the brake shoes. On AMC rear brakes, moving the tool handle downward typically retracts the shoes. You may need to push the adjuster lever away from the star wheel with a second tool.
4. 4

   Address seized drums with penetrating oil
   If the drum is seized to the axle hub flange by rust, apply penetrating oil around the center hub opening where the drum contacts the axle. Allow 10-15 minutes for penetration. Do not apply penetrant to the brake friction surface or shoes.
5. 5

   Remove seized drums using percussion method
   Using a rubber mallet, strike the drum face in a circular pattern around the outer edge, alternating sides to break the rust bond evenly. Strike with moderate force only. If the drum has cast bosses or flat areas on the back side, strike those instead to avoid damaging the friction surface. After several strikes, attempt removal by pulling straight outward.
6. 6

   Use drum puller if percussion fails
   If the drum remains seized, thread a drum puller into the two threaded holes provided in the drum face (1/2"-20 threads typical for AMC). Position the puller center bolt against the axle end and tighten gradually, alternating between puller bolts to maintain even pressure. The drum should release. If threaded holes are not present, a universal jaw-type puller can grip the outer edge of the drum.
7. 7

   Remove drum and inspect brake components
   Once free, slide the drum completely off the wheel studs and set aside with the friction surface facing up to prevent contamination. Inspect the brake shoes, springs, and wheel cylinder for damage, leakage, or excessive wear. Inspect the drum interior friction surface for deep grooves, cracks, or excessive wear.
8. 8

   Clean and measure drum
   Clean the drum interior friction surface with brake cleaner and a clean cloth. Measure the inside diameter with a drum micrometer or brake gauge. Maximum allowable diameter is typically cast into the drum outer edge. If the drum exceeds maximum diameter, is out-of-round by more than 0.006", or has deep grooves or cracks, it must be replaced.
9. 9

   Clean axle hub mounting surface
   Wire brush the axle flange and wheel stud area to remove rust and debris. This ensures the new or resurfaced drum will seat properly and concentrically. Clean wheel studs with a wire brush to ensure smooth drum installation and proper wheel mounting.
10. 10

    Install brake drum onto hub
    If installing new drums, ensure left and right drums are correct (some have offset bolt patterns). Align the drum over the wheel studs and slide it onto the axle hub. The drum should slide on easily and sit flush against the hub flange. If resistance is felt, do not force it; verify brake shoe adjustment is backed off and drum is correctly oriented.
11. 11

    Adjust brake shoes to drum
    Through the adjustment slot in the backing plate, rotate the star wheel adjuster to expand the brake shoes until the drum will not rotate freely. Then back off the adjuster 8-10 clicks until the drum rotates with only slight drag. Proper adjustment allows 1/8 to 1/4 turn of resistance when spinning the drum by hand. Both rear wheels should have equal drag.
12. 12

    Install wheel and torque lug nuts
    Mount the wheel onto the studs and hand-thread all lug nuts. Lower the vehicle slightly so the tire just contacts the ground to prevent rotation. Torque lug nuts in a star pattern to 75-80 ft-lbs (typical specification for 1970 AMC Rebel with standard wheels). Repeat for opposite side.

Reassembly

1. After both drums are installed and adjusted, lower vehicle completely and remove jack stands.
2. Perform final lug nut torque verification with vehicle on ground, following star pattern to 75-80 ft-lbs.
3. Pump brake pedal several times until firm pedal is achieved before moving vehicle.
4. If brake shoes or other components were replaced, bed in new brakes with 20-30 gentle stops from 30 mph before returning to normal driving.

Verification

• Test drive vehicle in a safe area at low speed (under 15 mph) and verify brakes engage smoothly without pulling to one side.
• Listen for abnormal scraping, grinding, or clicking noises from rear brakes during initial test stops.
• Verify parking brake holds vehicle on an incline after adjustment settles.
• After 50-100 miles, recheck rear brake adjustment and lug nut torque.
• If brake pedal feels soft or travels excessively, bleed brake system and recheck for leaks at wheel cylinders.

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