Information on 4T65-E MN7, M15 and M76 Front Wheel Drive Automatic Transmission Valve Body Reconditioning, DTCs P0741, P0742, P0757, P842, Harsh Shifts or Slips

The following new service information will aid technicians in providing easy to follow valve body reconditioning instructions and new illustrations to simplify reassembly of the valve body.

Important: If valve body cleaning is not required, DO NOT disassemble bores unless it is necessary to verify movement of valves.

Inspection Procedure

1. Using the exploded views in this bulletin, inspect each bore for freedom of valve(s) movement and evidence of debris. Pay particular attention to those valves related to the customer’s concern.
2. Verify movement of the valves in their normal installed position. Valves may become restricted during removal or installation. This is normal due to small tolerances between the valves and bores.
3. If a valve is restricted and cannot be corrected by cleaning the valve and bore, replace the valve body. Describe the restricted valve on the repair order.

Notice: Be sure all solenoids are installed with the electrical connectors facing the non-machined (cast) side of the valve body. Otherwise, the solenoids will bind against the transmission case as the valve body bolts are tightened and damage may occur.

Disassembly/Reassembly

1. If a valve is restricted by a metal burr from machining that bore, remove the valve and burr, then inspect movement in the valve’s normal position. If no other debris or restrictions are found, reassemble the valve body and install in the transmission.
2. If the valve body has been contaminated with debris from another transmission component failure, disassemble all bores for complete cleaning of all valve body components. If possible, keep individual bore parts separated for ease of reassembly. Use the following illustrations in this bulletin for a positive identification and location of individual parts:

•	Left Side Control Valve Body Assembly

•	Right Side Control Valve Body Assembly

•	Control Valve Body Assembly Chart, Valve Springs and Bore Plugs

Caution: Use appropriate eye protection when cleaning the valve body to prevent injury.

3. Using GM Brake Clean, or equivalent, in a safe and clean environment (clean aluminum pan) clean the valve body and dry it with compressed air.
4. Clean individual valve body components with GM Brake Clean, or equivalent. Coat each valve with clean ATF and reassemble in each bore. Check each valve for free movement during assembly of each bore.

Left Side Control Valve Body Assembly

Right Side Control Valve Body Assembly

1997-2000 M.Y. Only -- Right Side Control Valve Body Assembly

Valve Body Spring and Bore Plug Chart (Metric)

Valve Body Spring and Bore Plug Chart (Inch)