TM  10-3930-638-24&P 2-45.   WHEELS   AND   TIRES   TROUBLESHOOTING   (cont) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION 2. NOISY OR BUMPING SOUND WHILE TRAVELING (cont) Step 4. Remove axle shaft (para 2-39f and check wheel bearing for damage and insufficient lubricant (para 2-39f). a. If insufficient lubricant, lubricate wheel bearing (para 2-39f); if wheel bearing is damaged, replace (para 2-39f). b. If wheel bearing is okay, reinstall hub and drum assembly and axle shaft (para 2-39f), and remove wheels and tires (para 2-47). Disassemble tire from wheel and check for foreign material or damage (para 2-47); remove foreign material or replace tire if damaged (para 2-47). 2 - 4 6 .    S T E E R I N G    S Y S T E M    T R O U B L E S H O O T I NG MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION 1.  VEHICLE  WILL  NOT  TURN  WHEN  STEERING  WHEEL  IS  TURNED Step 1. Check oil level in hydraulic reservoir. Oil level should be between FULL and ADD marks with mast lowered. a. If oil level is not between FULL and ADD marks on dipstick with mast lowered, add oil (refer to  current  lubrication  order). b. If oil level is okay, proceed to step 2 below. Step 2. Check that steering bypass valve is closed (extreme clockwise position). a. If steering bypass valve is not in closed position, turn to the extreme clockwise position. b. If steering bypass valve is closed, proceed to step 3. Step 3. Check for oil leaks at connections to steering cylinders. a. If oil leaks are observed, tighten fittings or replace hoses (para 2-48b (1)). b. If oil leaks are not observed, proceed to step 4. Step 4. Start engine and operate at full throttle. Operate lift control lever, tilt control lever, and shift control lever. Check that mast assembly operates normally when levers are actuated. a. If mast assembly does not operate normally, proceed to step 5. b. If mast operates normally, replace steering gear (notify direct support maintenance). 2-321