Driveshaft - Rear

Removal and replacement of the rear driveshaft on a 1970 AMC Rebel Machine, including U-joint disconnection from the rear differential and transmission yoke.

Warnings

Tools required

Parts

• Rear driveshaft assembly × 1 — Use OEM specification or replacement
• U-joint strap bolts (if damaged) × 8 — 5/16 inch-24 grade 8

Preparation

1. Park vehicle on level, solid surface and engage parking brake firmly
2. Place wheel chocks in front of and behind front wheels
3. Raise rear of vehicle using floor jack at rear axle housing or frame rail
4. Support vehicle securely on jack stands placed under frame rails or designated lift points
5. Ensure vehicle is stable before working underneath
6. Allow exhaust system to cool completely if vehicle was recently driven

Procedure

1. 1

   Mark driveshaft orientation
   Using a permanent marker or paint pen, mark the relationship between the driveshaft and the rear axle pinion yoke. Also mark the front of the driveshaft to the transmission output yoke. These alignment marks are critical for maintaining proper driveline balance and phasing during reinstallation.
2. 2

   Position catch container
   Place a catch pan or container under the rear of the transmission extension housing. A small amount of transmission fluid may drip when the driveshaft is removed from the output shaft.
3. 3

   Remove rear U-joint strap bolts
   At the rear differential pinion yoke, locate the four U-joint strap bolts (two straps with two bolts each). Using a 9/16 inch socket and ratchet, remove all four bolts while holding the strap with a combination wrench to prevent spinning. Keep the straps and bolts together for inspection.
4. 4

   Separate rear U-joint from pinion yoke
   Carefully push the driveshaft forward toward the transmission to disengage the rear U-joint from the pinion yoke. The U-joint caps should slide out of the yoke easily. If stuck, gently tap with a rubber mallet. Have an assistant support the rear of the driveshaft or support it with one hand while separating.
5. 5

   Support and lower driveshaft rear section
   With the rear U-joint disconnected, carefully lower the rear of the driveshaft. Keep it angled downward to prevent the U-joint caps from falling off. Support the weight of the shaft to prevent it from binding at the front slip yoke.
6. 6

   Remove driveshaft from transmission
   Slide the driveshaft rearward to pull the slip yoke out of the transmission output shaft. The shaft should slide out smoothly once clear of the pinion yoke. Pull straight back to avoid damaging the transmission output seal. Be prepared for a small amount of fluid to drip.
7. 7

   Inspect U-joints and slip yoke
   With the driveshaft removed, inspect both U-joints for wear, looseness, or corrosion. Check the slip yoke splines for wear or damage. Examine the U-joint strap bolts for thread damage or stretching. Check all U-joint bearing caps to ensure they are secure and not leaking.
8. 8

   Clean mating surfaces
   Use a wire brush to clean the pinion yoke and transmission output shaft of any dirt, rust, or old grease. Clean the U-joint bearing caps and yoke surfaces. If installing the original driveshaft, clean the slip yoke splines and apply a light coat of high-temperature grease.
9. 9

   Install driveshaft front section
   Carefully insert the slip yoke into the transmission output shaft, aligning the splines. Push forward until the slip yoke is fully seated. Ensure the yoke slides smoothly without binding. The slip yoke should engage approximately 1 to 1.5 inches into the output shaft.
10. 10

    Align and install rear U-joint
    Raise the rear of the driveshaft and align the rear U-joint with the pinion yoke, matching your previously made alignment marks. Carefully position the U-joint bearing caps into the yoke ears. The caps should fit snugly but not be forced.
11. 11

    Install U-joint straps and bolts
    Position the U-joint straps over the bearing caps and align the bolt holes. Start all four strap bolts by hand to ensure proper thread engagement. Tighten the bolts in a criss-cross pattern to ensure even pressure on the bearing caps. Since no torque specification is provided in the database, tighten bolts firmly to approximately 15-17 ft-lbs or until straps are secure against the yoke. Verify U-joint rotates freely without binding.
12. 12

    Verify driveshaft alignment and clearance
    Rotate the driveshaft by hand to ensure it spins freely without binding or contacting the exhaust, frame, or floor pan. Check that all alignment marks are properly matched. Verify adequate clearance (minimum 1 inch) around the entire circumference of the driveshaft throughout its full rotation.

Reassembly

1. Ensure all U-joint strap bolts are tightened securely and evenly
2. Verify alignment marks on both ends of driveshaft match original positions
3. Check that slip yoke has adequate engagement with transmission output shaft
4. Confirm driveshaft has proper clearance from exhaust, frame, and floor components

Verification

• Rotate driveshaft by hand to confirm smooth operation without binding or unusual resistance
• Visually inspect that all U-joint strap bolts are installed and tight
• Check transmission fluid level and top off if necessary due to spillage during removal
• Start engine with transmission in neutral and listen for unusual noises or vibrations from driveline
• Test drive vehicle at various speeds (15-25 mph, 40-50 mph, and highway speed) to verify no vibration or unusual sounds are present

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