ATSG Toyota/Lexus U140/U240/U241 Transmission Rebuild Repair Manual

Introduction

This manual provides comprehensive technical information and step-by-step procedures for the overhaul, repair, and reassembly of Toyota and Lexus U140, U240, and U241 series automatic transmissions. It is designed for automotive technicians and individuals with a foundational understanding of automatic transmission systems. Adherence to the instructions within this manual is crucial for successful repair and optimal transmission performance.

Preparation for Use

Before beginning any repair work, ensure you have the necessary tools, equipment, and a clean, well-lit workspace. Review the entire manual to familiarize yourself with the procedures and required components. It is recommended to have all replacement parts, seals, and gaskets readily available before disassembly. Always refer to the vehicle manufacturer's service information for specific torque specifications and fluid types.

• Safety First: Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves.
• Cleanliness: Maintain a clean environment to prevent contamination of transmission components.
• Reference Materials: Keep this manual open to the relevant section during each step of the repair process.

Using This Manual

This manual is organized into sections covering specific transmission components and repair procedures. Each section includes detailed diagrams, exploded views, and textual instructions. Follow the steps sequentially. Pay close attention to warnings, cautions, and notes provided throughout the text, as these highlight critical information for safety and proper function.

• Diagrams and Illustrations: Utilize the provided visual aids to identify components and understand assembly order.
• Component Identification: Refer to part numbers and descriptions to ensure correct component usage.
• Torque Specifications: Always use a calibrated torque wrench for all fasteners where specifications are provided.

Maintenance Procedures Covered

This manual details the procedures for disassembling, inspecting, repairing, and reassembling the U140, U240, and U241 automatic transmissions. Key areas covered include:

• Valve body removal and inspection
• Clutch pack disassembly and reassembly
• Planetary gear set inspection
• Pump assembly overhaul
• Seal and gasket replacement
• Component clearance checks

The manual does not cover routine vehicle maintenance such as fluid changes or filter replacements unless they are part of a larger transmission overhaul procedure.

Troubleshooting Guidance

While this manual primarily focuses on repair procedures, it implicitly aids in troubleshooting by providing correct assembly and operational specifications. If a transmission exhibits symptoms after a rebuild, refer back to the relevant sections to verify:

• Correct component installation and orientation.
• Proper torque application for all fasteners.
• Absence of foreign material or debris.
• Correct fluid levels and types as per vehicle manufacturer specifications.

For diagnostic trouble codes (DTCs) or specific vehicle-related issues, consult the vehicle's factory service manual in conjunction with this transmission manual.

Specifications

Warranty Information

This manual is a technical publication. Information regarding warranties for the manual itself is typically provided by the retailer or publisher at the point of purchase. This manual does not provide a warranty for the transmission components or the repair work performed using its instructions.

Support

For technical support related to the content of this ATSG manual, please refer to the contact information provided by ATSG (Automatic Transmission Service Group) directly, if available within the physical manual or on their official website. For inquiries regarding the purchase or delivery of this manual, please contact your retailer.