0385530 JOHNSON COVER & TRANSFER ASSY.

Introduction
This Special Instruction provides the procedure in order to repower a 631D, 633D, 637D, and 639D Wheel Tractor. The replacement engine will be a Tier I level 3408 engine. See Table 1 for the engine arrangement numbers. The Wheel Tractor was originally equipped with a 3408 engine. The original engine is not regulated for emissions. This Special Instruction will provide the information in order to install the Tier I level replacement engine.
Table 1
Engine Arrangement
Original Engine Replacement Engine
4N-6724 Engine Ar
8N-7812 Engine Ar
2W-0631 Engine Ar 225-0396 Engine Ar(1)
10R-1561 Complete Engine Ar(2)
(1) New Repower Engine
(2) RemanThis Special Instruction does not include procedures that can be found in your existing manuals. Refer to the original Service Manual, Parts Manual, and Operation and Maintenance Manual for more information.When you have completed this procedure, prepare the machine for service. Refer to the Operation and Maintenance Manual.Note: Do not perform any procedure in this Special Instruction until the information has been read and understood.Registering the Retrofit
Reference: Special Instruction, REHS5097, "Instructions to Register the Retrofit"Documenting changes to a machine configuration is an advantage to Caterpillar and the dealer technicians that are sent to repair a machine. By identifying that the machine has been reconfigured, the technician will have a better opportunity to have the correct parts, tooling, and service information. Identifying that the machine has been reconfigured will also allow Caterpillar to include the retrofitted serial numbers in applicable Service Letters.Safety
Personal injury or death can result from sudden machine movement.Sudden movement of the machine can cause injury to persons on or near the machine.To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.
Do not attempt to assemble this machine until you read and you understand the assembly instructions.Improper assembly procedures could result in injury or death.
Personal injury or death can result from improper lifting or blocking.When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component.Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Welding on Electronically Controlled Engines
Proper welding procedures are necessary in order to avoid damage to electronic controls. Perform welding on the engine according to the following procedure.
Set the engine control to the "STOP" mode.
Turn off the fuel supply to the engine.
Disconnect the negative terminal from the battery.
Disconnect the electronic components from the engine wiring harnesses: ECM, throttle actuator, actuator for the turbocharger compressor bypass, fuel metering valve and sensors.
Protect the wiring harnesses from welding debris and/or from welding spatter.
Do NOT use electrical components (ECM or sensors) or electronic component grounding points for grounding the welder.
Connect the welder ground cable directly to the engine component that will be welded. Place the clamp as close as possible to the weld in order to reduce the possibility of current damage to the engine components.
Use standard welding procedures to weld the materials together.Parts Needed
Reference: Refer to Parts Manual, SEBP5316, "3408E Engine Emissions Repower Tier I For 631D,633D,637D, And 639D Wheel Tractor".Note: The required parts are subject to some change. Refer to TMI for the most recent required parts list.Note: If part fabrication is necessary, ensure that all fabricated parts are deburred. Use caution when deburring parts. Avoid excessive grinding and notches.Note: A breakdown of the kit provides a parts list for the repower. The kit part number is not serviceable. Order the engine arrangement plus the list of parts prov