CHAPTER 111 MODELS 9500, 9501 ONLY SECTION 1 INTRODUCTION

Transcription

1 CHAPTER 111 MODELS 9500, 9501 ONLY SECTION 1 INTRODUCTION Models 9500 and 9501 Lawn-Boy compact riders are propelled by a conventional, geared transmission with two forward speeds and one reverse. The maximum speed in second gear is 3.6 mph. In first gear and reverse the maximum speed attained is 2.2 mph. A 5 h.p. recoil start Briggs and Stratton 4 cycle engine with a maximum rpm range of from 3400 rpm to 3600 rpm powers the Mower. For service see an authorized Briggs and Stratton dealer. A unique feature is the aircraft-type steering which offers ease and comforto the operator. The 26 inch floating pan may be adjusted to 5 different cutting positions between 1-1/2 inches and 3-1/2 inches. The front wheels are semi-pneumatic while the rear tires are fully pneumatic and maintain pounds air pressure. The front axle is full floating and the main frame is of tube type to provide maximum strength. The overall length is 55-1/2" and 28-3/16" wide. SERVICE BULLETIN REFERENCES

2 MODELS 9500, 9501 ONLY SECTION 2 SPECIFICATIONS ENGINE Idle rpm rpm's Operating rpm rpm's maximum Oil requirement SAE 30 Wt. service MS Crankcase capacity 2 pints Spark plug Champion CJ8-Autolite A7N Front size Rear size. Pressure TIRE SPECIFICATIONS 10 x 3.50 semi-pneumatic.13 x PSI SECTION 3 LUBRICATION I I LAWN-BOY "A" GREASE NOTE I OR EQUIVALENT taken be must Care not to allow oil to come in contact with brake band 1. Lubricate both front wheels zerk at lining transmission at aterial fittings. stop. on blade friction or 2. Lubricate rear axle bearings at zerk fittings (2 places). SAE #30 OIL 1. All six pivot points in the mower pan suspension linkage. PETROLEUM JELLY 1. Felt washers rear wheels liberally coat. LAWN-BOY "A" GREASE 2. Rod end and ball joints. 3. Mower engagement lever pivot. 1. Bell arms Foot pedal liberally coat i.d. of boss on frame castings and rodfoot rest. 4. Transmission clutch mechanism. 2. Pivot pin front axle fill reservoir. 5. Blade clutch mechanism. 6. Axle pan wheels. 3. Pivot pin on bell arm and pin assembly transmission clutch idler liberally coat pin.

3 MODELS 9500, 9501 ONLY 4. Front axle king voirs (2 places). TRANSMISSION pin bores - fill reser- 12 oz. of Shell "Darina Ax" grease or equivalent evenly distributed within transmission and on camplate. DIFFERENTIAL.75 to 1.25 ounces of Shell Expro grease or equivalent. The thrusting area of each gear and shaft bearing surfaces should be greased. SECTION 4 HARDWARE TORQUES Torque to values given for thread size unless listed separately. THREAD SIZE /4-20 5/ / /8-16 3/8-24 TORQUE 35 to 38 inch lbs. 63 to 75 inch lbs. 142 to 170 inch lbs. 142 to 170 inch lbs. 190 to 225 inch lbs. 235 to 280 inch lbs. DESCRIPTION Screw - chain guard Screw - mower pan brackets to pan Nut - "U" bolt to frame Nut - Trans idler pulley to idler arm Bolt Seat Nut Mower wheel axle to pan bracket Nut wheel spindle to axle Nut pivot mower pan suspension Nut blade Screw transmission case halves Screw transmission cover plate Screw transmission shift forks TORQUE 45 to 59 inch lbs. 91 to 119 inch lbs. 91 to 119 inch lbs. 149 to 195 inch lbs. 355 to 465 inch lbs. 355 to 465 inch lbs. 195 to 255 inch lbs. 372 to 487 inch lbs. 459 to 600 inch lbs. 70 to 80 inch lbs. 20 to 25 inch lbs. 35 to 45 inch lbs. SERVICE BULLETIN REFERENCES

4 MODELS 9500, 9501 ONLY SECTION 5 TROUBLESHOOTING STEERING I PROBLEM CAUSE I Hard steering Blade won't turn Blade won't disengage Blade leaves swirl marks in lawn Lack of lubricant Bearings and/or bushings worn Tie rods bent Steering arm broken BLADE HOUSING AND BLADE Belt off pulleys Belt damaged Blade nut loose Seized bearings Blade adapter broken Blade brake not working Blade control mechanism broken Housing unlevel Blade unlevel or bent REMEDY Lubrication Section 3 Steering disassembly and inspection Section 6 Straighten or replace Section 6 Disassembly and replacement Section 6 Replace Section 7 Replace Section 7 Tighten Section 7 Refer to Spec. Sheet Torque Check blade brake spring Correct housing level Section 7 Replace blade Section 7 Blade belt comes off (Rear) Blade belt comes off (Front) Belt keeper loose Broken belt Top idler pulley broken or bent Pulley shaft loose Rear idler spring broken Rear idler arm broken or bent Broken belt Bottom idler pulley broken or bent Intermediate pulley shaft loose Idler arm broken or bent Engine belt pulley bent or broken Adjust and tighten Replace Replace Tighten Replace Replace Replace Replace Tighten Replace Replace SERVICE BULLETIN REFERENCES

5 MODELS 9500, 9501 ONLY PROBLEM DRIVE PROBLEMS CAUSE REMEDY Mower will not propel Chain loose Chain broken Differential broken Sprocket worn or broken Drive belt broken or damaged Transmission won't shift Adjust Repair or replace Repair or replace - Section 10 Replace Section 8 Replace Section 8 Repair Section 8 Engine will not start Engine slows down and stops Black carbon or sooty deposit Pitted or burned electrodes, white, light tan or blistered deposits. Rapid wear of electrode Cracked or broken Plug Cracked or broken insulator on lower end of plug Widening of gap FUEL TROUBLE a. Fuel tank empty a. Fill tank b. Water in fuel b. Drain fuel from tank and carburetor and replace with fresh fuel c. Old fuel in tank gums up tank, fuel line and carburetor d. Shut-off valve closed a. Vent hole in fuel tank cap plugged b. Fuel line or strainer clogged c. Empty out old fuel and clean all parts involved d. Open valve a. Unplug hole c. Fuel tank runs dry c. Refill tank SPARK PLUG TROUBLE a. Breaker points dirty or out of adjustment b. Weak condenser c. Incorrect plug a. Incorrect plug a. Careless installation of plug a. Center electrode strained when regapping Plug a. Normal wear _- b. Clean out fuel line or strainer a. Clean and adjust gap b. Check and replace if weak c. Install correct plug a. Install correct plug a. Replace plug a. Replace plug a. Clean and regap SERVICE BULLETIN REFERENCES 11-59

6 MODEL 9500 ONLY STEERING SHAFT AND ARM ASSEMBLY PEDAL BELL FOOT REST ASSEMBLY PEDAL AND FOOT REST SUPPORT ROD AND STEERING GREASE FITTING FIGURE 3-1

7 MODEL 9501 ONLY STEERING HANDLE STEERING SHAFT AND ARM ASSEMBLY FOOT REST ASSEMBLY PEDALANDFOOT RESTSUPPORTROD AND STEERING GREASE FITTING FIGURE 3-1 A SERVICE BULLETIN REFERENCES 11-61

8 MODELS 9500, 9501 ONLY SECTION 6 FRONT END STEERING The steering is positive type. The steering shaft controls front wheel movement thru a steering arm, tie bar and tie rod. FRONT AXLE REMOVAL Disconnect spark plug lead; raise the front of the mower up resting vertically on the rear cover plate and engine. NOTE During disassembly examine all parts for excessive wear or damage. SPINDLE AND STEERING ARM REMOVAL Disconnect the spark plug lead; raise the front of the mower up resting it vertically on the rear cover and engine. SAFETY WARNING SECURE TO WALL OR OTHER FIXED OBJECT TO PREVENT TIP- PING OR FALLING. SAFETY WARNING SECURE TO WALL OR OTHER FIXED OBJECT TO PREVENT TIP- PING OR FALLING. Remove the wheels and spindle and steering arm assemblies. Remove axle pivot pin retaining ring and pull pin from steering housing and slide axle out of steering housing. Reassemble in reverse order. Remove the wheel and disconnectie rod Apply a liberal amount of Lawn-Boy A from the steering arm. Remove the steergrease or Lubriplate 63OAA lubricant to ing arm spindle nut on top of axle and pull pivot pin and other friction points. spindle and steering arm from axle housing. Remove the upper and lower bearing and spacer, STEERING CASTING & STEERING and examine for wear. Apply a coating of Lawn- SHAFT REMOVAL! Boy A grease or Lubriplate 63OAA lubricant before reinstalling. Reassemble in reverse order. Remove the front axle and steering handle, detach the steering tie bar ball joint from the steering arm, disconnect brake and clutch rod linkage at rear of unit. Remove pedal and foot rest support rod retainer ring from either side and drive rod out of foot rests, pedals and steering housing. 3-2 Remove the two (2) bolts securing the steering housing to the main frame and pull steering housing and control rods away from main frame. NOTE remaining bolts Remove the from nuts the The left and right hand spindle and in the steering housing, leaving the bolts in place. Place the frame casting on the floor steering arms are not interchange- or work bench with the bolt heads down and able. separate halves of the housing to expose REFERENCES BULLETIN SERVICE

9 FIGURE 3-3 ~-- MODELS 9500, 9501 ONLY the steering shaft and arm assembly, nylon bushings and the two pedal bell arm assemblies. Thoroughly clean the inside of the housing halves with a suitable solvent. Do not wash or wipe nylon bushings with solvent. Apply Lawn-Boy A grease or Lubriplate 630AA lubricant to nylon bushings before reinstalling. The nylon bushings include 2 ribs. When reinstalling, these ribs must be located in matching grooves in the steering casting halves. Figure 3-3. SERVICE BULLETIN REFERENCES a e a a e a e a 11-63

10 I- MODELS 9500, 9501 ONLY STEERING WHEEL ALIGNMENT If the steering wheel does not line up properly with the front wheels, it can be aligned as follows: 1. Remove the nut securing ball jointo king pin arm. 2. Loosen the jam nut at the ball joint socket and turn the ball joint onto or off the rod, see Figure 3-4, until the steering wheel is aligned with the front wheels. During assembly all moving parts and friction points such as bearings, bushings, and bolt threads should be lubricated with Lawn-Boy A grease or Lubriplate 620AA lubricant. The front wheel bearing and axle must be lubricated every hours of operation with either of the above mentioned lubricants. Note grease fitting in Figure Check wheels for alignment. 4. Assemble the ball joint to the king pin arm and tighten the jam nut. MODEL 9500 ILLUSTRATED FIGURE 3-4 MODEL 9500 ILLUSTRATED FIGURE 3-5 _ SERVICE BULLETIN REFERENCES ---

11 -I- MODELS 9500, 9501 ONLY LINK IDLER SPRING BLADE SPINDLE BRACKET BRACKET RETAINING RING BLADE HOUSING WHEEL I HOUSING FIGURE 3-6 SERVICE BULLETIN REFERENCES 11-65

12 MODELS 9500,9501 ONLY SECTION 7 BLADE DRIVE & BLADE HOUSING ASSY, The cutting blade is driven by a system of V belts and pulleys. The primary drive pulley is keyed to the engine crankshaft. A short 31-3/4 inch V belt runs from the primary pulley to the top pulley of the intermediate pulley and spindle assembly. The blade spindle pulley is in turn powered by a longer 48-3/8 inch belt driven by the bottom, pulley of the intermediate pulley and spindle assembly. These are specially designed belts for these specific applications. Standard "V" belts will not give satisfactory life. Two idler pulleys are used in the blade drive system. One is located under the belt cover adjacent to the blade drive pulley; it is always engaged with the V belt. The other idler is a part of a combination rear blade drive belt idler and blade brake assembly. It is located adjacent to the top pulley of the intermediate pulley and spindle assembly. It is actuated by the blade engagement lever. When it is in "on" position the idler pulley is engaged with the belt. When it is in "off" position a blade brake engages with the top pulley of the intermediate pulley assembly stopping the cutting blade within six (6) seconds. BLADE PULLEY I I I I \ \ \ \ \ \ \ RETAINER \ \ \ \ \ \ PULLEY ='FRONT BELT TOP VIEW FIGURE SERVICE BULLETIN REFERENCES

13 MODELS 9500, 9501 ONLY BELT REPLACEMENT FRONT BELT Disconnect the spark plug lead and remove the belt cover. Slip a length of rope thru the eye of the belt idler spring and pull spring off hook to release tension. See Figure 3-8. REAR BELT Disconnect spark plug lead; raise the front of the mower up resting it vertically on the rear cover and engine. SAFETY WARNING SECURE TO WALL OR OTHER FIXED OBJECT TO PREVENT TIP- PING OR FALLING. Disconnect primary (rear) belt idler spring; loosen the belt keeper and roll the belt off the pulley system. Replace reverse in order. BLADE HOUSING REMOVAL Remove the front blade belt and remove retainer clip from either side of front pan support rod and slide rod out. Remove shoulder bolts from rear pan, link arms at pan and slide mower housing out from under mower chassis. Reassemble in reverse order. BLADE PULLEY SPINDLE TO' BEARING REMOVAL Remove blade housing, blade, and blade adapter. Remove woodruff key from blade spindle and drive threaded end of spindle with a soft headed hammer (rubber or plastic) out of the spindle housing. Reassemble in reverse order. To remove spindle bearing, remove bearing retaining ring inside lower end of spindle housing. BLADE HOUSING HEIGHT (CUTTING) ADJUSTMENT NOTE The cutting blade may be set at five dif- After installation of belt, pin on belt ferent heights, from 1-1/2 to 3-1/2 inches. keeper assembly must be positioned To adjust, simply position the front pan supas pictured in Figure 3-9. port rod in the desired hole in the adjustment plate. The rear adjustment is made Belt may now be removed. Replace in re- similarly by placing the rear wheel axle in order. verse the adjustment plate. desired the in position SERVICE BULLETIN REFERENCES 11-67

14 MODEL 9500 ONLY SEAT FRAME REAR BLADE PULLEY DRIVE BELT TRANSMISSION FIGURE SERVICE BULLETIN REFERENCES

15 MODEL 9501 ONLY TRANSMISSION PULLEY SERVICE BULLETIN REFERENCES 11-69

16 TRANSMISSION DRIVE BELT REPLACEMENT Secure the clutch pedal with rope as illustrated in Figure Disconnect the spark plug lead and raise the unit vertically and rest on rear cover and engine. MODELS 9500, 9501 ONLY SECTION 8 TRANSMISSION SAFETY WARNING SECURE TO WALL OR OTHER FIXED OBJECT TO PREVENT TIP- PING OR FALLING. Remove the rear blade belt (bottom drive pulley). See Rear Belt Replacement. Transmission belt may now be rolled off pulleys. This belt is 44 inches in length. TRANSMISSION BELT IDLER ADJUSTMENT With the clutch pedal depressed, adjust the belt keeper so there is 1/4" to 3/16" as shown in Figure TRANSMISSION PULLEY REPAIR OR REPLACEMENT Remove transmission belt and retaining ring from transmission shaft. The pulley is keyed to the shaft. Carefully work pulley off shaft. Inspect key before reinstalling pulley and retaining ring. INTERMEDIATE SPINDLE & PULLEY ASSEMBLY MODEL 9500 ILLUSTRATED FIGURE 3-11 This assembly may not be dismantled. If damage has occurred to the shaft, pulleys or housing, the entire assembly must be replaced. To replace, remove the two housing screws.

17 the MODELS 9500, 9501 ONLY REAR BLADE DRIVE BELT PULLEY IDLER 2. Loosen screw and slide blade brake to & BRAKE ASSEMBLY MODEL 9500 ONLY end of slot. Tighten screw securely. To repair Or rep1ace; mower On end 3. Brake must ride in center of belt. Adjust,secure to wall or other fixed object. Remove the rear belt and idler spring. as required. Disconnect blade engagement linkage rod and remove nut securing idler pulley arm. BLADE CLUTCH IDLER-ADJUSTMENT To remove idler pulley and or brake as- MODEL 9500 ONLY sembly, remove idler pulley bolt from idler Remove idler spring. Adjust length of conarm. trol rod and ball joint to enable end of con- When reinstalling, brake shoe must be trol rod to slip freely into hole in bell arm aligned with pulley. Keep shoe free of dirt on blade control assembly, when ball joint and oil. Refer to Blade Adjustment for is installed on idler arm and control rod is brake adjustment. resting on frame. Shorten length of control After installation of rear blade drive belt, rod and ball joint assembly one complete pin on belt keeper (afixed to idler pulley turn of ball joint. Assemble spring and searm) assembly must be positioned against cure cotter pin and nut. Re-check for edge of idler arm and secured in place. proper adjustment. REAR BLADE DRIVE BELT IDLER PULLEY BLADE CLUTCH IDLER ADJUSTMENT BELT RETAINER ADJUSTMENT MODEL 9501 ONLY MODEL 9501 ONLY To adjust: retainer be flush to 1/32 inch Remove cotter pin and washer securing rod from belt when blade control lever is placed to control assembly. Loosen jam nut and in "OFF" position. To adjust loosen nut on remove rod from ball joint. Thread rod into pulley and move retainer proper ball joint nine (9) revolutions and secure rod clearance is achieved. Tightennut securely. to ball joint with jam nut. rod BLADE BRAKE ADJUSTMENT control to assembly, secure using washer MODEL 9500 ONLY and cotter pin previously removed. Blade clutch idler is now properly adjusted. The cutting blade must stop in not less than 3 or more than 6 seconds when the blade THROTTLE CONTROL ADJUSTMENT engagement arm is placed in "off" position. MODELS 9500, 9501 ONLY To adjust the blade brake: 1. Loosen cable retaining clip on engine. 1. Detach the blade engagement rod from 2. Place throttle lever in "Fast" position. the brake and idler pulley bell arm. This 3. Place speed control arm on in is done by unscrewing the 5/16" nut be- fastest possible position without engaging tween the ball joint and bell arm. choke. 2. Loosen the lock nut securing the ball the to joint brake rod. 4. Tighten cable retaining clip. 3. Screw the ball joint in a clockwise man- 5. Check to insure engine kill switch is enner to shorten the travel of the rod and gaged when throttle control lever is counterclockwise to lengthen the travel placed in until the desired length is attained for "Stop" position. 6. Check to insure choke on engine is in proper braking. full choke position when throttle control BLADE BRAKE ADJUSTMENT lever is not quite at full end of "choke" MODEL 9501 ONLY position. The cutting blade must stop in not less than ENGINE REMOVAL MODELS 9500, or more than 6 seconds when the blade ONLY engagement arm is placed in "off" position. Disconnect spark plug and throttle linkage. To Detach brake pull back spring and remove adjust the blade brake: rear blade belt,and transmission drive belt. 1. Place blade clutch control in "OFF" PO- Remove drive pulley and woodruff key and remove sition. mounting bolts. SERVICE BULLETIN REFERENCES 11-71

18 MODEL 9501 ONLY TRANSMISSION DISASSEMBLY SEQUENCE 1. Bolt 2. Nut Cotter pin Brake spring Washer Brake band pin Brake band Key Retainer Brake drum Lower housing Needle bearing Thrust washer Bevel pinion Retaining ring 3 5. Clutch collar 36. Clutch collar 37. Spur gear 38. Gear 39. Shoulder screw 40. Screw 41. Cover plate detent 42. Detent. spring 43. Detent ball 44. Shifter fork 45. Upper housing 46. Bolt 47. Cam plate 48. Nylon slide 49. Shift lever 50. Shifter knob 51. Tap cover plate 52. Bracket 53. Washer 16. Key 17. Input shaft 18. Washer 19. Retaining ring 20. Retaining ring 21. Retaining ring 22. Sprocket 23. Flanged bearing 24. Output shaft 25. Drive shaft 26. Key 27. Key 28. Key 29. Key 30. Key 31. Spur gear 32. Spur gear 33. Sleeve bearing 34. Bevel gear FIGURE 3-1 3

19 MODEL 9500 ONLY TRANSMISSION DISASSEMBLY SEQUENCE 1. Lower housing 2. Retainer 3. Washer 4. Flanged bearing 5. Spur & bevel gear 6. Spur gear 7. Clutch collar 8. Clutch collar 9. Bevel gear 10. Sleeve bearing 11. Spur gear 12. Spur gear 13. Output shaft 14. Key 15. Drive shaft 16. Key 17. Key 18. Retaining ring Sprocket 22. Retaining ring 23. Brake retainer 24. Input shaft 25. Key 26. Needle bearing 27. Thrust washer 28. Bevel pinion 29. Retaining ring 30. Shift fork 31. Ball bearing 32. Detent spring 33. Detent cover plate 34. Screw 35. Screw 36. Upper housing 37..Bolt 38. Cam plate 39. Nylon slide 40. Shift lever 41. Shifter knob 42. Top cover plate 43. Bracket I FIGURE 3-1 3A SERVICE BULLETIN REFERENCES 11-73

20 MODELS 9500, 9501 ONLY TRANSMISSION DISASSEMBLY GENERAL For illustration purposes, we have shown the transmission removed completely from the mower. Any repairs, except replacing the lower transmission housing, can be made while the assembly is mounted on the mower. See Figures 3-13 and 3-13A. Remove the seven screws securing the top housing and shift handle assembly to the lower housing. The top housing assembly can be lifted clear. The complete gear trains are now exposed for removal and inspection or replacement. Also see Figures 3-15 and SHIFT HANDLE REMOVAL If the shift handle "snaps" from one shift position to another, this assembly is operating properly and it is not necessary to disassemble or remove it to' make repairs internally on the transmission. See Figures 3-13 and 3-13A for disassembly sequence. Note top and bottom of the cam plate location of springs (2) and ball bearings (2). These parts must be reassembled exactly or the shift mechanism will not function properly. Also see Figure FIGURE 3-15 FIGURE 3-14 TRANSMISSION GEARBOX Remove the transmission drive chain cover. Locate the connecting link in the drive chain and remove. See Figure Remove cotter pin securing brake shoe to brake drum SERVICE BULLETIN REFERENCES

21 MODELS 9500, 9501 ONLY 1. All parts should be washed clean with a grease solvent such as Stoddards, or kerosene. All excess solvent should then be blown off the parts so that they are dry. Use Shell Co. "Darina AX" grease for relubrication of transmission. 2. Check external sprocketo insure that sprocket is not broken or that key is not sheared. 3. Lift shaft assemblies out of lower housing. Inspect all parts for damage and replace damaged parts. Clutch collars must slide freely. 4. Check lower housing for damage and replace if necessary. The input shaft assembly should not be removed from the lower housing unless a part replacement is necessary. Check the input shaft needle bearings for. excessive wear. This can be accomplished by rotating the input shaft and feeling the clearance. The clearance should be minimal for proper operation. 5. Relubricate lower housing by evenly distributing six (6) ounces of lubrication. Care should be taken to completely lubricate the pinion gear and thrust washer underneath the gear. 6. Replace shaft assemblies in lower housing taking care to install the locking tabs on the flange bearings in the cavities provided the in housing. Relubricate shaft assemblies by evenly distributing six (6) ounces of lubrication throughout the complete gear train. 7. Lubricate shifter cam plate with grease. 8. Replace upper housing onto lower housing and bolt securely into place. GENERAL This model mower is braked thru the transmission. The transmission driveshaft has a sprocket (drive chain) on one end and a brake drum on the other end. See Figure A spring loaded brake shoe wraps around the drum and is actuated by the brake pedal. BRAKE ADJUSTMENT MODEL 9500 ONLY Proper brake adjustment will allow the brake drum to turn freely while machine is moving. When the brake pedal is pushed, the brake shoe will tighten on the drum and stop the mower. See Figure Adjustment is made by lengthening or shortening the rod from the brake pedal to the brake shoe. This is accomplished with the turnbuckle. Loosen the two jam nuts prior to adjustment. Re-secure them after proper brake adjustment is achieved. BRAKE ADJUSTMENT MODEL 9501 ONLY Proper brake adjustment will allow the brake drum to turn freely while mower is moving.when the brake pedal is depressed the brake shoe will tighten on the drum and stop the mower. Adjustment is achieved SECTiON 9 WHEEL BRAKE SERVICE BULLETIN REFERENCES 11-75

22 ~~~~~ ~ ~ MODELS 9500, 9501 ONLY with the brake pedal pulled back against stop. Ad- tween brake drum and brake band lining as shown just brake band assembly using the brake band in Figure Tighten jam nuts and mounting mounting screw and jam nuts on brake rod until screw securely. See Figure there is approximately 1/64-1/32 inch clearance be- SECTION 10 REMOVING DIFFERENTIAL.DRIVE SPROCKET Remove the spark plug lead. Stand mower on end, resting on engine. Secure mower so it will not tip during repairs. Locate and remove the master link on drive chain. See Figure Remove chain, see Figure Remove the rear wheels and bearing assemblies (2). Slide the differential out of the chassis. The sprocket can now be removed or the differential disassembled for further repair or replacement. DIFFERENTIAL NOTE parts should be thoroughly washed with a suitable solvent. The axle and gear assemblies must be replaced as a unit as the gears are permanently secured to their respective axles. Care should be taken not to damage the mating surfaces of the When reinstalling master link, open casting halves as there is no gasket used to seal end must face toward front of unit the assembly. on chain slack side. DIFFERENTIAL REPAIR LUBRICATING DIFFERENTIAL Follow the instructions under REMOVING Prior to reassembly or lubrication all parts should DIFFERENTIAL DRIVE SPROCKET and be cleaned as stated under DIFFERENTIAL remove the drive sprocket. Remove all screws REPAIR. Pack the differential with a good grade securing the differential casting halves together. of packing lubricant i.e. Lawn-Boy A grease or. The differential parts can now be removed for in- automotive chassis grease. spection and replacement. See Figure All SERVICE BULLETIN REFERENCES

23 MODEL 9500 ONLY CLUTCH SPRING REAR WHEEL ANDBEVELGEAR SHORT AXLE ANDBEVELGEAR \ SPROCKET FIGURE 3-20

24 MODEL 9501 ONLY CHAIN GUIDE CLUTCH SPRING REAR WHEEL AND BEVEL GEAR SPROCKET FIGURE 3-20A SERVICE BULLETIN REFERENCES

25 MODELS 9500, 9501 ONLY 1. Remove spark plug lead. Stand mower on, end resting on engine. Secure mower so it will not tilt or fall.. 2. Loosen the nut on the chain tensioner. 3. Use a screwdriver to apply tension to the chain. Tighten to 3/32 inch maximum chain slack. REAR WHEEL BEARING & AXLE LUBRICATION FIGURE 3-21 The rear wheel bearing should be lubricated every hours of operation with Lawn-Boy Type A lubricant or a good automotive type chassis grease. See Figure DRIVE CHAIN TENSION The chain tensioner is located under the chassisupport bar. See Figure Occasionally this may have to be tightened to maintain correct chain tension. FIGURE MODEL 9501