Driveshaft - Front

This procedure covers removal and installation of the front driveshaft on a 1972 Ford F-100 with 302ci V8, including center support bearing removal if equipped with a two-piece driveshaft.

Warnings

Tools required

Parts

• Driveshaft flange bolts × 4 — Use OEM specification if torque-to-yield
• Center support bearing assembly × 1 — Use OEM specification
• Universal joint × 1 — Use OEM specification
• Transmission output shaft seal × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake firmly.
2. Chock front wheels securely to prevent vehicle movement.
3. Raise rear of vehicle using floor jack at rear axle housing or frame rails.
4. Support vehicle securely on jack stands placed under frame rails behind cab mount area.
5. Ensure adequate working clearance beneath vehicle (minimum 18 inches recommended).
6. Inspect driveshaft, universal joints, and center support bearing for visible damage or wear before disassembly.
7. Place drain pan beneath transmission tail housing in case of fluid seepage during removal.

Procedure

1. 1

   Mark driveshaft-to-flange alignment
   Using white paint marker or chalk, make alignment marks across the rear driveshaft yoke and the rear axle pinion yoke where they mate. The front slip yoke splines are self-indexing. Make a second mark across the rear driveshaft flange and rear axle pinion yoke. These marks ensure the driveshaft is reinstalled in the exact same orientation to maintain factory balance. Mark multiple surfaces on each joint to ensure visibility after disassembly.
2. 2

   Remove front driveshaft-to-transmission flange bolts
   The front of the driveshaft attaches to the transmission via a slip yoke that slides into the tail housing (no flange bolts). If your truck instead uses a two-piece shaft with a flanged front joint, locate the flange fasteners at that joint. Using appropriate socket (typically 1/2 inch or 9/16 inch), loosen and remove all 4 bolts. You may need to rotate the driveshaft by turning the rear wheels (with transmission in neutral and parking brake released) to access all bolt positions. Keep bolts organized as they may be torque-to-yield and require replacement.
3. 3

   Support front driveshaft section
   Position a floor jack with block of wood or have assistant support the weight of the forward section of the driveshaft to prevent it from dropping suddenly when disconnected. The driveshaft weighs approximately 15-20 pounds and can cause injury if allowed to fall.
4. 4

   Separate front driveshaft from transmission yoke
   With weight supported, carefully pull the driveshaft flange away from transmission output yoke. If resistance is encountered, use gentle prying with flathead screwdriver between flange surfaces. Do not damage the transmission output seal. Once separated, lower the forward end of driveshaft assembly slightly to provide clearance for center support bearing removal.
5. 5

   Remove center support bearing bracket bolts
   This step applies only if the truck has a two-piece driveshaft. If a center support bearing is present, locate its bracket on the crossmember and remove its mounting bolts; otherwise skip this step. Using appropriate socket (typically 1/2 inch or 9/16 inch), remove both bolts completely. Support the driveshaft assembly weight during this operation to prevent strain on the rear U-joint.
   Torque spec

   Center Support Bearing Bracket Bolts50 Nm (37 lb-ft)
6. 6

   Remove rear driveshaft-to-axle flange bolts
   Working at the rear axle pinion yoke, remove the two U-bolts (or bearing-cap straps) securing the rear U-joint bearing caps to the pinion yoke. Retain the bearing caps so the needle bearings do not fall out. Again, you may need to rotate the driveshaft to access all bolt positions. Keep these bolts separate from front bolts if they are different specifications.
7. 7

   Remove complete driveshaft assembly
   With all fasteners removed, carefully lower and slide the complete two-piece driveshaft assembly (including center support bearing) out from under the vehicle. The assembly will be approximately 6-8 feet long and awkward to handle. Move slowly to avoid hitting brake lines, fuel lines, or exhaust components. Place assembly on clean workbench or storage area away from traffic.
8. 8

   Inspect slip yoke and transmission seal
   With driveshaft removed, inspect the transmission tail housing output shaft and seal for leakage, wear, or damage. Check for excessive play in the output shaft bearing. If seal is leaking or damaged, this is the optimal time for replacement. Stuff a clean shop rag into the transmission tail housing opening to prevent fluid loss and contamination entry.
9. 9

   Inspect and service driveshaft assembly
   On the workbench, thoroughly inspect both universal joints for wear, binding, or looseness. Check the center support bearing for roughness, noise, or excessive play by rotating the inner race. Inspect driveshaft tubing for dents, cracks, or damage. If universal joints show wear (rust staining, looseness, or binding), replace them. If center support bearing has any roughness or play, replace the complete bearing assembly. Clean all flange surfaces with wire brush and solvent.
10. 10

    Install driveshaft assembly into position
    Carefully maneuver the complete driveshaft assembly back under the vehicle. Guide the rear U-joint flange into position at the rear axle pinion yoke first, aligning your previously made chalk marks. Support the front section and position the center support bearing bracket approximately in its mounting location on the crossmember. Have assistant support weight or use floor jack with wood block.
11. 11

    Install rear driveshaft flange bolts
    Align the rear driveshaft U-joint flange to the rear axle pinion yoke using your alignment marks. Install all 4 flange bolts finger-tight initially to ensure proper engagement. If U-bolts are used, tighten the U-bolt nuts evenly to approximately 15 lb-ft (verify Ford spec). If a 4-bolt flange is actually present, torque those bolts in a cross pattern per Ford specification. Rotate driveshaft as needed to access each bolt position.
12. 12

    Install center support bearing bracket
    Position the center support bearing bracket to the crossmember mounting location. The rubber cushion in the bearing assembly should sit flush against the bracket. Install both mounting bolts finger-tight initially, then torque to 50 Nm (37 lb-ft) in sequence. Do not overtighten as this can preload the bearing and cause premature failure.
    Torque spec

    Center Support Bearing Bracket Bolts50 Nm (37 lb-ft)
13. 13

    Install front driveshaft flange bolts
    Align the forward driveshaft U-joint flange to the transmission output yoke using your alignment marks. The marks must line up exactly to maintain driveline balance. Install all 4 flange bolts finger-tight initially. Once all bolts are engaged, tighten in a cross pattern to 75 Nm (55 lb-ft) using torque wrench. Verified detail (The front of a standard F-100 driveshaft is a slip yoke that slides into the transmission tail housing — there are no front flange bolts to install or torque. This entire installation step describes hardware that does not exist on this platform.): Slide the front slip yoke into the transmission tail housing, ensuring it seats fully onto the output shaft splines. No front flange bolts are used. Verify the tail housing seal is not damaged during installation.
14. 14

    Final inspection and cleanup
    Remove shop rag from transmission tail housing if inserted. Verify all bolts are properly torqued and no tools or hardware remain under vehicle. Check that driveshaft has adequate clearance from exhaust, frame, and brake lines throughout its full range of motion. Wipe away any excess grease or fluid. Check transmission fluid level if seal was replaced or fluid loss occurred.

Reassembly

1. Driveshaft alignment marks are critical - misalignment will cause vibration and premature wear.
2. Center support bearing should be installed without preload - do not overtighten mounting bolts.
3. If driveshaft flange bolts are torque-to-yield specification, use new bolts on installation.
4. After installation, rotate driveshaft by hand to verify smooth rotation without binding or interference.

Verification

• Start engine and verify no abnormal noises or vibrations from driveline.
• Test drive vehicle at various speeds (15-30 mph and 45-60 mph) to check for vibration or noise.
• Listen for clunking sounds during acceleration and deceleration which may indicate worn U-joints or loose fasteners.
• After test drive, re-inspect all flange bolts for proper torque and center support bearing mounting bolts for tightness.
• Check transmission tail housing area for fluid leaks if seal was replaced.
• Verify no rubbing marks on driveshaft from contact with exhaust, frame, or brake lines.

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