TM 9-2320-279-10-1 Change 8 2-45 Table 2-1. Preventive Maintenance Checks and Services for Models M977 thru M985E1 Location Item No. Interval Item to Check/ Service Crewmember Procedure Not Fully Mission Capable If: DRIVER 14 Before Gear Shift (Non- FHTV only) a.  Transmission Check transmission shift le- ver operation. With engine switch in “ON” position, move shift lever from “N” to “1” then back to “N”. Lever should move freely through all range detents. Lever  inoperable  or binds between range detents. b.  Transfer Case CAUTION Vehicle must be parked when making this check. Transfer case will be damaged if shifted while vehicle is moving. Check transfer case shift le- ver operation. With transmis- sion in “N” shift transfer lever through all range positions. Lever  should  move  freely through all range positions. Lever  inoperable  or binds between range detents. 15 Before Engine Retarder Check engine retarder for proper operation. With engine running and transmission in neutral “N” run engine at 1900 to 2100 rpm. Place  engine  brake  switch  to “ON”. Lift foot off throttle treadle and listen for a popping or chatter- ing sound, which indicates the en- gine brake is engaged. Engine   retarder   does not engage. 16 Before Steering Check steering wheel for operation. With engine running, turn steering wheel from left to right. Steering wheel should move freely. Steering wheel inoperable or binds.