Replace the rear main crankshaft seal by removing the transmission, flexplate/flywheel, and seal housing to prevent oil leaks at the rear of the engine block.

Warnings

Tools required

Parts

• Rear main crankshaft seal × 1 — Use OEM specification
• Rear main seal housing gasket × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Transmission fluid cooler line O-rings × 2 — Use OEM specification

Fluids

• Toyota Genuine 0W-20 Engine Oil — 5 qt
• Toyota WS ATF (automatic transmission) — 3 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine and transmission to cool completely (minimum 2 hours)
3. Disconnect negative battery terminal and secure away from battery post
4. Raise vehicle and support securely on jack stands at all four corners
5. Remove engine undercovers and splash shields
6. Drain engine oil and transmission fluid into appropriate containers
7. Mark driveshaft-to-transmission alignment with paint or marker
8. Take photos of all electrical connectors and hose routing for reference

Procedure

1. 1

   Remove exhaust and driveshafts
   Disconnect oxygen sensors and remove exhaust front pipe/catalytic converter assembly. Remove both front axle shafts by removing hub nuts, lower ball joint pinch bolts, and prying axles from transmission. Support axles with wire to avoid CV joint damage.
2. 2

   Disconnect transmission external components
   Disconnect shift cable from transmission lever and bracket. Disconnect all electrical connectors including neutral safety switch, solenoid harness, and speed sensors. Disconnect transmission fluid cooler lines and plug openings to prevent fluid loss and contamination. Remove starter motor mounting bolts and set aside.
3. 3

   Support engine and transmission
   Place transmission jack under transmission pan with wood block to distribute load. Install engine support bar across engine bay or attach hoist to engine lift points. Remove rear transmission mount and crossmember bolts, then lower crossmember away.
4. 4

   Remove transmission mounting bolts
   Remove all transmission-to-engine mounting bolts. There are typically 6-8 bolts of varying lengths around the bell housing perimeter. Note bolt locations and lengths for reassembly. Remove lower engine-to-transmission brace if equipped.
   ⚠Ensure transmission jack is properly positioned and secure before removing final mounting bolts.
   Torque spec

   Transmission-to-Engine Bolts55 Nm (41 lb-ft)
5. 5

   Separate and remove transmission
   Carefully pry transmission away from engine using pry points on bell housing. Do not pry on soft aluminum surfaces. Once torque converter/input shaft clears engine, slowly lower transmission on jack and roll away from vehicle. Keep transmission level to prevent torque converter from sliding out.
   ⚠️Have assistant guide transmission while lowering. Transmission can shift unexpectedly.
6. 6

   Remove flexplate or flywheel
   Lock crankshaft rotation using flywheel holding tool or large pry bar wedged between flexplate teeth and bell housing. For automatic transmission, remove 6 flexplate bolts in crisscross pattern. For manual transmission, remove 8 flywheel bolts in star pattern. Remove flexplate/flywheel and set aside on clean surface.
   ⚠Mark flexplate/flywheel orientation to crankshaft before removal to maintain balance.
   Torque spec

   Flexplate Bolts85 Nm (63 lb-ft)
7. 7

   Remove rear main seal housing
   Remove all rear main seal housing bolts from engine block. There are typically 8-10 bolts around perimeter. Carefully pry housing away from block using plastic pry tools at designated pry points. Clean all old gasket material and RTV from engine block and housing mating surfaces using scraper and brake cleaner.
   ⚠Do not damage aluminum sealing surfaces. Use plastic scrapers only.
   Torque spec

   Rear Main Seal Housing12 Nm (9 lb-ft)
8. 8

   Remove old rear main seal
   Using seal removal tool or carefully with flat-blade screwdriver, pry old seal from housing. Work around perimeter evenly to avoid cocking seal. Thoroughly clean seal bore in housing with brake cleaner and inspect for grooves or damage that could cause new seal to leak.
9. 9

   Install new rear main seal
   Lightly coat outer edge of new seal with clean engine oil. Position seal in housing bore with lip facing toward engine. Using seal driver or large socket matching seal outer diameter, drive seal squarely into housing until fully seated and flush with housing face. Ensure seal is not cocked or damaged.
   ⚠Do not damage seal lip during installation. Seal must sit perfectly square in bore.
10. 10

    Install seal housing with new gasket
    Install new gasket on seal housing or apply thin bead of RTV silicone to housing mating surface per Toyota specifications. Lightly oil seal lip with clean engine oil. Carefully slide housing over crankshaft, ensuring seal lip is not damaged. Install all housing bolts hand-tight, then torque in crisscross pattern to specification.
    ⚠If using RTV, allow 15-30 minutes setup time before installing. Do not overtighten housing bolts as this can distort housing and cause leaks.
    Torque spec

    Rear Main Seal Housing12 Nm (9 lb-ft)
11. 11

    Install flexplate or flywheel
    Clean crankshaft flange and flexplate/flywheel mating surfaces with brake cleaner. Align flexplate/flywheel to crankshaft using alignment marks made during removal. Install bolts with thread locker if specified. Tighten bolts in star pattern in multiple passes to final torque specification while holding crankshaft with holding tool.
    ℹ️If flywheel bolts are TTY (torque-to-yield), they must be replaced and tightened in star pattern per manufacturer specifications.
    Torque spec

    Flexplate Bolts85 Nm (63 lb-ft)
12. 12

    Reinstall transmission
    Ensure torque converter is fully seated in transmission pump (automatic) or input shaft moves freely (manual). Apply small amount of high-temp grease to pilot bearing/bushing. Raise transmission into position, align with engine, and carefully slide transmission onto engine dowel pins. Install all transmission-to-engine bolts and torque to specification in crisscross pattern.
    ⚠Transmission must slide onto engine easily. Do not force with bolts or damage will occur.
    Torque spec

    Transmission-to-Engine Bolts55 Nm (41 lb-ft)
13. 13

    Reinstall transmission mounts and components
    Install transmission crossmember and mount. Torque all mount bolts to specification. Remove transmission jack and engine support. Reconnect transmission cooler lines with new O-rings. Reinstall starter motor. Reconnect all electrical connectors and shift cable. Install both axle shafts into transmission and hubs.
    ℹ️Verify transmission cooler lines are fully seated and secure before adding fluid.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
14. 14

    Complete reassembly and fill fluids
    Reinstall exhaust system and torque all fasteners. Install new oil drain plug crush washer and install drain plug to specification. Refill engine with 5.0 quarts Toyota 0W-20 oil. Add approximately 3.0 quarts ATF to transmission through dipstick tube (automatic) or fill plug (manual). Reinstall undercovers and lower vehicle.
    Torque spec

    Oil Drain Plug35 Nm (26 lb-ft)

Reassembly

1. Verify all bolts are torqued to specification and no tools are left in engine bay
2. Double-check all electrical connectors, hoses, and cables are reconnected
3. Verify axle shafts are fully seated in transmission with new retaining clips installed
4. Check that transmission is filled to proper level per Toyota procedure (engine running, transmission at operating temperature)

Verification

• Reconnect battery and start engine, checking for proper oil pressure immediately
• With parking brake engaged, cycle through all transmission gear positions to verify proper operation
• Bring engine to operating temperature and verify no leaks from rear main seal area
• Test drive vehicle and verify normal transmission operation and no unusual noises
• After test drive, recheck oil and transmission fluid levels and inspect for leaks
• Monitor oil level over next 100 miles and inspect seal area regularly for first week

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