Driveshaft - Rear

This procedure covers the removal and installation of the rear driveshaft on a 2015-2020 Ford F-150 with 3.5L EcoBoost V6 engine and RWD configuration.

Warnings

Tools required

Parts

• Rear driveshaft assembly × 1 — Use OEM specification for RWD 3.5L EcoBoost
• Driveshaft U-joint strap bolts × 4 — Replace if damaged or corroded

Fluids

• Motorcraft 75W-140 Synthetic Gear Oil — 0.25 qt

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks at front wheels to prevent rolling
3. Raise rear of vehicle using floor jack at rear differential
4. Support vehicle securely on jack stands at frame rails behind rear axle
5. Lower floor jack but keep it positioned under differential for support
6. Ensure adequate working clearance under vehicle

Procedure

1. 1

   Mark driveshaft alignment
   Using paint marker, make alignment marks across the driveshaft flange and rear differential pinion flange. Also mark the driveshaft slip yoke orientation to the front driveshaft section. These marks are critical for maintaining proper driveshaft phasing and preventing vibration after installation.
2. 2

   Position drain pan
   Place drain pan under transmission tailshaft extension housing. When the driveshaft slip yoke is removed, a small amount of transmission fluid may drain from the tailshaft seal. Have shop towels ready to minimize spillage.
3. 3

   Remove rear U-joint straps
   Locate the four U-joint strap bolts at the rear differential pinion flange. Remove all four bolts using a 12mm or 13mm socket (verify size on your specific vehicle). Keep straps and bolts together for reinstallation. Do not allow driveshaft to drop or hang unsupported.
4. 4

   Support driveshaft
   Support the rear of the driveshaft with one hand or a transmission jack. Carefully separate the rear U-joint from the pinion flange by prying gently if necessary. Rotate the driveshaft slightly to disengage the U-joint caps from the flange yoke.
5. 5

   Lower driveshaft rear section
   Carefully lower the rear section of the driveshaft. Use wire or zip ties to secure the rear U-joint caps to prevent them from falling off and losing needle bearings. Rest the rear of driveshaft on the floor jack or axle housing, ensuring it does not hang unsupported.
6. 6

   Remove driveshaft from transmission
   Slide the front slip yoke rearward out of the transmission tailshaft extension housing. Pull straight back with steady pressure. The driveshaft will slide out approximately 6-8 inches before fully disengaging. Catch any fluid that drains with shop towels and drain pan.
7. 7

   Remove driveshaft from vehicle
   Once slip yoke is clear of transmission, carefully maneuver the complete driveshaft assembly out from under the vehicle. Keep driveshaft level to prevent remaining transmission fluid from draining out of slip yoke. Set driveshaft on clean work surface.
8. 8

   Plug transmission tailshaft
   Insert a clean shop towel or appropriately sized plug into the transmission tailshaft extension housing to prevent additional fluid loss and contamination. This also prevents dirt and debris from entering the transmission.
9. 9

   Inspect components
   Inspect the removed driveshaft for worn U-joints, damaged slip yoke splines, bent tubing, or missing balance weights. Check differential pinion flange for damage or excessive wear. Verify transmission tailshaft seal is not leaking or damaged. Replace components as needed before reinstallation.
10. 10

    Prepare new or serviced driveshaft
    If installing new or rebuilt driveshaft, verify it matches the removed unit in length and configuration. Ensure all U-joint caps are properly retained with clips or straps. Lightly lubricate slip yoke splines with thin coat of transmission fluid or appropriate grease. Do not over-lubricate.
11. 11

    Install slip yoke into transmission
    Remove plug or towel from transmission tailshaft. Carefully align slip yoke splines with transmission output shaft splines. Insert slip yoke straight into tailshaft extension housing, pushing firmly until fully seated. Slip yoke should slide in smoothly without binding. You should feel it engage the splines and seat completely.
12. 12

    Align rear U-joint to differential
    Raise rear section of driveshaft and align the rear U-joint with differential pinion flange yoke. Match your alignment marks made during disassembly. Rotate driveshaft as necessary to align U-joint caps with flange yoke holes. Ensure proper phasing is maintained.
13. 13

    Install U-joint straps and bolts
    Position U-joint straps over the U-joint caps and align with bolt holes in pinion flange. Install all four strap bolts finger-tight first to ensure proper alignment. Once all bolts are started, tighten evenly in a cross pattern to specified torque. Verify U-joint caps are fully seated in flange yoke before final torquing.
14. 14

    Verify installation
    Check that slip yoke is fully engaged in transmission (should have 1-2 inches of slip travel remaining). Verify all U-joint strap bolts are torqued properly. Ensure driveshaft can rotate freely without binding or interference. Remove all tools and drain pan from under vehicle.
15. 15

    Check and top off transmission fluid
    Check transmission fluid level per manufacturer procedure. Add Motorcraft MERCON LV ATF as needed to replace any fluid lost during driveshaft removal. Do not overfill.

Reassembly

1. Carefully remove jack stands and lower vehicle to ground
2. Torque specifications are critical - verify all fasteners are torqued to spec
3. Alignment marks must be matched to prevent driveline vibration
4. Ensure adequate slip yoke engagement in transmission tailshaft

Verification

• Start engine and verify no transmission fluid leaks at tailshaft seal
• With vehicle still in park, verify no unusual noises from driveline
• Test drive vehicle at various speeds (25, 45, 65 mph) to check for vibration
• Any vibration indicates improper phasing or unbalanced driveshaft - recheck alignment marks
• Listen for clunking during acceleration/deceleration which may indicate loose U-joint straps
• Recheck all fastener torque after test drive

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