This procedure replaces the transmission pan gasket on the U660E automatic transmission, requiring fluid drain, pan removal, gasket replacement, and refill with Toyota WS ATF.

Warnings

Tools required

Parts

• Transmission pan gasket × 1 — Use OEM Toyota gasket for U660E transmission
• Transmission drain plug crush washer × 1 — 90430-18008 or equivalent

Fluids

• Toyota WS ATF — 4 qt

Preparation

1. Park vehicle on level surface and apply parking brake
2. Allow transmission to cool if vehicle was recently operated
3. Raise vehicle using floor jack and support securely on jack stands at manufacturer lift points
4. Verify adequate clearance to access underside of transmission
5. Place oil drain pan beneath transmission pan area

Procedure

1. 1

   Remove transmission drain plug
   Locate the transmission drain plug on the bottom of the transmission pan. Using a 10mm socket, loosen and remove the drain plug. Allow fluid to drain completely into the drain pan. This will take 5-10 minutes for full drainage.
   ⚠Fluid may still be warm. Ensure drain pan is positioned correctly as fluid flow can be strong initially.
   Torque spec

   Transmission Drain Plug30 Nm (22 lb-ft)
2. 2

   Remove transmission pan bolts
   Using a 10mm socket, remove all transmission pan bolts in a criss-cross pattern, starting from the outer bolts and working inward. There are typically 16-19 bolts securing the pan. Keep bolts organized for reinstallation.
   Torque spec

   Pan Bolts16 Nm (12 lb-ft)
3. 3

   Lower transmission pan
   Carefully lower the transmission pan. Some residual fluid will remain in the pan, so tilt slowly to drain into your collection pan. The pan may be stuck to the gasket; gently tap with a rubber mallet if needed to break the seal.
   ⚠Pan will contain residual fluid. Keep level while lowering to avoid spills.
4. 4

   Inspect transmission pan and filter
   Examine the pan for metal shavings or debris. Small amounts of fine material are normal, but large chunks or excessive metal indicate internal wear. The internal filter on this transmission is not serviceable during pan removal and should not be disturbed.
   ℹ️The U660E transmission has an internal filter that is not replaceable during routine pan service.
5. 5

   Clean transmission pan
   Thoroughly clean the inside of the transmission pan using brake cleaner and shop rags. Remove all old gasket material and debris. Ensure the magnet (if equipped) is cleaned and will be reinstalled in the same location. Clean the drain plug threads and inspect for damage.
6. 6

   Clean transmission mating surface
   Using a plastic scraper, carefully remove all old gasket material from the transmission housing mating surface. Do not use metal scrapers that could damage the aluminum surface. Wipe clean with brake cleaner and ensure the surface is completely dry and free of debris.
   ⚠Do not allow debris to fall into the open transmission. Stuff clean rags around openings if needed.
7. 7

   Install new gasket
   Position the new transmission pan gasket on the pan, aligning all bolt holes. Most OEM gaskets are rubber-coated metal and do not require additional sealant. Ensure the gasket is oriented correctly and seated properly in any locating features.
8. 8

   Reinstall transmission pan
   Carefully raise the transmission pan with gasket into position. Start all pan bolts by hand to ensure proper thread engagement. Tighten bolts in a criss-cross pattern, starting from the center and working outward, to the specified torque of 12 Nm (9 lb-ft).
   ⚠Over-tightening pan bolts will distort the pan and cause leaks. Use a torque wrench.
   Torque spec

   Pan Bolts16 Nm (12 lb-ft)
9. 9

   Reinstall drain plug
   Install a new crush washer on the drain plug. Thread the drain plug into the transmission pan by hand, then tighten to 30 Nm (22 lb-ft) using a torque wrench. Do not over-tighten.
   Torque spec

   Transmission Drain Plug30 Nm (22 lb-ft)
10. 10

    Refill transmission fluid
    Lower the vehicle to the ground. Remove the transmission dipstick (located near the firewall on the driver side). Using a funnel, add 3.5 quarts of Toyota WS ATF through the dipstick tube. Start the engine and allow it to reach normal operating temperature while cycling through all gear positions.
    ⚠Only add fluid through the dipstick tube. Do not overfill as this can cause transmission damage.
11. 11

    Check fluid level and adjust
    With the engine running and transmission at normal operating temperature (180-200°F), shift through all gears and return to Park. Check the fluid level on the dipstick with the engine running. The level should be in the HOT range. Add fluid in 0.25 quart increments if needed. Recheck for leaks under the vehicle.

Reassembly

1. Ensure all pan bolts are torqued to specification in the correct criss-cross pattern
2. Double-check drain plug is tight with new crush washer installed
3. Verify no tools or rags were left in the work area

Verification

• Start engine and verify no leaks from transmission pan or drain plug
• With engine at operating temperature, verify fluid level is in HOT range on dipstick while engine is running
• Test drive vehicle through all gears to confirm normal operation
• Recheck fluid level after test drive and top off if necessary
• Inspect underneath vehicle after test drive for any signs of leakage

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