This procedure covers replacement of the rear main crankshaft seal on a 2011-2014 Ford F-150 with 3.5L EcoBoost V6 engine, requiring transmission removal to access the seal housing.

Warnings

Tools required

Parts

• Rear main crankshaft seal × 1 — Use OEM Ford specification
• Transmission pan gasket × 1 — Use OEM specification
• Transmission filter (if equipped) × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• RTV silicone gasket maker × 1 — Motorcraft TA-30 or equivalent

Fluids

• Motorcraft MERCON LV ATF — 11 qt
• Motorcraft 5W-20 Synthetic Blend — 6 qt

Preparation

1. Disconnect negative battery cable and wait 10 minutes for airbag system to deplete
2. Raise vehicle on lift or support securely on 4 jack stands at manufacturer lift points
3. Remove engine skid plate if equipped
4. Drain engine oil at drain plug and allow to drain completely
5. Drain transmission fluid by removing transmission pan (retain fluid for level assessment)
6. Remove transmission filter if equipped
7. Install engine support fixture or hoist to support engine weight from above
8. Mark front driveshaft-to-transfer case relationship with paint pen for proper alignment on reinstallation

Procedure

1. 1

   Remove driveshafts and exhaust components
   Remove front and rear driveshafts, marking yoke positions before removal. Remove exhaust system from catalytic converters back to provide clearance for transmission removal. Support exhaust with wire or stands to prevent damage to hangers.
2. 2

   Disconnect transfer case linkages and wiring
   Disconnect transfer case shift linkage or electronic shift motor connector. Disconnect transfer case speed sensor connectors and vent hose. Remove transfer case skid plate mounting bolts.
   ℹ️Label all electrical connectors with tape to ensure proper reconnection.
3. 3

   Disconnect transmission connections
   Disconnect transmission cooler lines at transmission using line disconnect tool. Cap lines to prevent fluid loss and contamination. Disconnect transmission harness connector, output speed sensor, and reverse light switch connector. Remove shift cable from transmission lever and bracket.
4. 4

   Remove starter motor
   Disconnect starter motor electrical connections. Remove starter mounting bolts and remove starter motor from bellhousing. Set aside in safe location.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
5. 5

   Support and remove transmission crossmember
   Position transmission jack under transmission pan with wood block to distribute load. Secure transmission to jack with safety chain or strap. Remove transmission mount-to-crossmember fasteners, then remove crossmember-to-frame bolts. Lower transmission slightly and remove crossmember.
   ⚠️Ensure transmission is securely fastened to transmission jack before removing crossmember support.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
6. 6

   Access and mark flexplate
   Remove transmission dust cover/inspection plate from bellhousing. Mark flexplate-to-torque converter position with paint pen. Rotate crankshaft using 22mm socket on crankshaft bolt to access all flexplate-to-torque converter bolts through inspection opening.
7. 7

   Remove flexplate-to-torque converter bolts
   Remove all flexplate-to-torque converter bolts while rotating crankshaft to access each bolt. Ensure torque converter is pushed fully into transmission and will not come out with bellhousing. Support torque converter with wire or strap if necessary.
   ⚠Do not allow torque converter to fall out when transmission is separated. Tape or wire converter to transmission housing.
   Torque spec

   Flexplate Bolts85 Nm (63 lb-ft)
8. 8

   Remove transmission-to-engine bolts
   Remove all transmission-to-engine bellhousing bolts. Note bolt locations as some may be different lengths. Support transmission weight on jack and verify engine is properly supported from above before removing final bolts.
   Torque spec

   Transmission-to-Engine Bolts55 Nm (41 lb-ft)
9. 9

   Separate and lower transmission
   Carefully slide transmission rearward away from engine, ensuring torque converter remains in transmission. Lower transmission on jack and roll out from under vehicle. Plug transmission input shaft opening with clean rag to prevent contamination.
   ⚠️Transmission is extremely heavy. Move slowly and ensure clear path before lowering.
10. 10

    Remove flexplate
    Mark flexplate-to-crankshaft orientation with paint pen. Use flywheel holding tool or wedge to prevent crankshaft rotation. Remove all flexplate mounting bolts in reverse of tightening sequence (working outward from center in star pattern). Remove flexplate from crankshaft.
    ℹ️Inspect flexplate for cracks, heat damage, or damaged ring gear teeth. Replace if any damage is found.
    Torque spec

    Flexplate Bolts85 Nm (63 lb-ft)
11. 11

    Remove rear main seal housing
    Remove all rear main seal housing bolts. Carefully pry housing away from engine block using plastic pry tool in designated pry slots. Do not damage sealing surfaces on block. Remove housing and old gasket material.
    Torque spec

    Rear Main Seal Housing12 Nm (9 lb-ft)
12. 12

    Remove old seal and clean surfaces
    Use seal removal tool or screwdriver to carefully pry old seal from housing. Be careful not to gouge or scratch housing bore. Clean all gasket surfaces on housing and engine block thoroughly with gasket scraper and brake cleaner. Inspect crankshaft sealing surface for grooves or damage. Polish minor imperfections with 400-grit sandpaper.
    ⚠If crankshaft sealing surface has deep grooves, seal may leak even after replacement. Consider repair sleeve or crankshaft replacement for severe damage.
13. 13

    Install new rear main seal
    Lightly lubricate new seal lip with clean engine oil. Position seal in housing with lip facing toward engine. Use seal installation tool or appropriately-sized large socket to drive seal squarely into housing bore until fully seated and flush with housing face. Verify seal is not cocked or damaged during installation.
14. 14

    Install seal housing
    Apply thin bead of RTV silicone to engine block sealing surface per Ford service procedure. Install new gasket on housing if equipped, or use RTV only per manufacturer specification. Install housing over crankshaft, being careful not to damage seal lip. Install all housing bolts finger-tight, then torque in crisscross pattern from center outward.
    ℹ️Allow RTV to set for at least 30 minutes before adding engine oil per manufacturer specifications.
    Torque spec

    Rear Main Seal Housing12 Nm (9 lb-ft)
15. 15

    Reinstall flexplate and transmission
    Install flexplate to crankshaft in original orientation using alignment marks. Install flexplate bolts and torque in star pattern working from center outward. Apply threadlocker to bolts if specified by manufacturer. Position transmission on jack and align with engine. Slide transmission forward onto engine dowels while aligning torque converter with flexplate. Install all transmission-to-engine bolts and torque to specification. Reinstall flexplate-to-torque converter bolts through inspection opening, rotating crankshaft to access all bolts. Torque to specification.
    Torque spec

    Flexplate Bolts85 Nm (63 lb-ft)

    Transmission-to-Engine Bolts55 Nm (41 lb-ft)

Reassembly

1. Reinstall transmission crossmember and torque all mounting bolts to specification
2. Remove transmission jack and engine support fixture
3. Reinstall starter motor and torque mounting bolts to specification
4. Reconnect all transmission electrical connectors, shift cable, and cooler lines
5. Reinstall transfer case linkage, wiring, and skid plate
6. Reinstall driveshafts in original orientation per alignment marks
7. Reinstall exhaust system with new gaskets if necessary
8. Install new oil drain plug crush washer and torque drain plug to specification
9. Reinstall engine skid plate if equipped
10. Fill transmission with Motorcraft MERCON LV ATF to proper level per dipstick or fill procedure
11. Fill engine with Motorcraft 5W-20 Synthetic Blend oil to proper level
12. Reconnect negative battery cable

Verification

• Start engine and verify no leaks from rear main seal area while observing from underneath
• Check transmission fluid level with engine at operating temperature in Park position
• Check engine oil level and top off if necessary
• Test drive vehicle through all gears and verify proper transmission operation
• Recheck for leaks after test drive, inspecting rear main seal area, oil pan, and transmission pan
• Verify no unusual noises from transmission, transfer case, or driveline
• Monitor oil level over next several days to confirm seal is not leaking

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