Method of rebuilding solenoids for automatic transmissions

Abstract

A method of rebuilding a solenoid for use in automatic transmissions is disclosed. In one embodiment, an improvement over the original equipment design allows for increased durability of the solenoid. In another embodiment, a lower cost method is disclosed for reusing an expensive component. In either case, various components within the solenoid are reused, reconditioned or replaced. A preferred process for disassembling the solenoid is also disclosed.

1 - 19 . (canceled) 
     
     
         20 . A method for restoring a used solenoid and valve assembly from an automatic transmission, comprising:
 providing a new bushing, and a used solenoid assembly including a solenoid housing connected to a valve housing, the solenoid housing holding within it an electromagnetic actuator supported by a used bushing, the valve housing holding within it a spool valve movable by the actuator along an axis;   testing the hydraulic characteristics of the used solenoid assembly by applying a range of electrical currents to the solenoid to move the spool valve within a range of positions;   comparing the tested hydraulic characteristics to OEM hydraulic characteristics;   removing the used bushing;   installing a new bushing after said removing; and   retesting the hydraulic characteristics of the used solenoid assembly with the new bushing by applying the range of electrical currents to the solenoid to move the spool valve within a range of positions.   
     
     
         21 . The method of  claim 20  wherein the member is a set screw. 
     
     
         22 . The method of  claim 20  wherein said testing is of the pressure drop of the solenoid assembly as a function of electrical current. 
     
     
         23 . The method of  claim 20  wherein said testing is of the of the fluid flow of the solenoid assembly as a function of electrical current. 
     
     
         24 . The method of  claim 20  wherein said providing includes the used bushing supported by a used member, said removing the used bushing is from the used member, and said installing a new bushing is into the used member. 
     
     
         25 . A method for restoring a used solenoid and valve assembly, comprising:
 providing a used solenoid assembly including a solenoid housing connected by a crimped mechanical connection to a valve housing, the solenoid housing holding within it an electromagnetic actuator, the valve housing holding within it an actuatable valve element movable by the actuator,   removing at least two, separated segments of the crimped connection;   retaining the remainder of the crimped connection after said removing; and   pulling apart the used valve housing from the used solenoid housing after said removing and after said retaining.   
     
     
         26 . The method of  claim 25  wherein said pulling inelastically deforms the remainder of the crimped connection. 
     
     
         27 . The method of  claim 25  wherein said pulling is by holding the used housing, holding the used valve housing, and pulling the used housing and used valve housing in opposite directions. 
     
     
         28 . The method of  claim 25  wherein the spool valve is movable by the actuator along an axis and said pulling is along the axis. 
     
     
         29 . The method of  claim 25  wherein said removing is by machining away a portion of at least one of the used housing and the used valve housing within each segment. 
     
     
         30 . The method of  claim 25  wherein said removing is by machining away a portion of the used housing and a portion of the used valve housing within each segment. 
     
     
         31 . The method of  claim 25  which further comprises replacing one of the used valve housing or the used spool valve with a corresponding different valve housing or spool valve, and reassembling the one used and the one replaced into the used housing. 
     
     
         32 . The method of  claim 25  which further comprises reassembling a valve housing into the used housing after said pulling and recrimping the used housing to the valve housing. 
     
     
         33 . The method of  claim 32  wherein said recrimping is of the remainder of the crimped connection. 
     
     
         34 . The method of  claim 25  wherein said providing includes a powdered metal valve housing, and which further comprises reassembling the powdered metal valve housing into the used housing. 
     
     
         35 . A method for restoring a used solenoid and valve assembly, comprising:
 providing a used solenoid assembly including a solenoid housing connected by a crimped connection to a valve housing, the housing holding within it an electromagnetically actuator, the valve housing holding within it a spool valve movable by the actuator along an axis,   separating the solenoid housing from the valve housing;   disassembling the used valve housing and used spool valve from the used solenoid assembly;   replacing the used spool valve with a different spool valve, the different valve have substantially the same dimensional relationships in the axial direction as the used spool valve, the different valve having larger metering diameters than the corresponding metering diameters of the used valve;   increasing the inner diameters of the metering lands of the used valve housing to receive therethrough the corresponding metering diameters of the different valve;   reassembling the different spool valve and the used valve housing with increased inner diameters with the housing; and   testing the flow characteristics of the reassembled solenoid assembly.   
     
     
         36 . The method of  claim 35  wherein said increasing is by mechanically reaming each inner diameter. 
     
     
         37 . The method of  claim 36  wherein said mechanically reaming is with a stepped reamer. 
     
     
         38 . The method of  claim 36  wherein each inner diameter is mechanically reamed simultaneously with each other inner diameter. 
     
     
         39 . The method of  claim 35  wherein the used solenoid assembly demonstrated electrohydraulic flow characteristics within a range of OEM flow characteristics when new, and wherein said testing verifies that the reassembled solenoid assembly demonstrates electrohydraulic flow characteristics within the OEM range.