SELF-PROPELLEDUPPER BELT DRIVESERVICING

Transcription

1 SELF-PROPELLEDUPPER BELT DRIVESERVICING CLUTCH CONTROL ROD ADJUSTMENT Proper control rod adjustment exists when there is 3/16 clearance between the drive rollers and rear wheels with control handle in OUT OF DRIVE position. See Figure 1. TO ADJUST: 1. Place all wheels at same cutting height. 2. Place control handle in OUT OF DRIVE position. 3. EARLIER MODELS (See Figure 2) Remove spring clip. Remove upper control rod from control handle. Loosen wing nut and locknut from turnbuckle as shown in Figure 3. Turn upper control rod into or out of turnbuckle until 3/16 dimension (see Figure 1) is achieved with upper control rod reinstalled on control handle in the OUT OF DRIVE position. I FIGURE 3 TURNBUCKLE UPPER CONTROL ROD CONTROL 3. LATER MODELS (See Figure 4) Loosen wingnut and locknut from turnbuckle as shown in Figure 3. Adjust turnbuckle until the 3/16 dimension is obtained. See Figure Secure turnbuckle with wingnut and locknut. SERVICE BULLETIN REFERENCES 10-7

2 SELF-PROPELLED SERVICING (UPPER BELT DRIVE) DRIVE ROLLERS Both drive rollers must engage the mower wheels at the same time, To adjust, loosen top nut and bolt on right side of link and grip assembly and move drive shaft in or out until rollers are equal distance from the wheels. Tighten nut and bolt securely. _- LUBRICATION Drive shaft needle bearings: Unscrew grease plug from end of each drive shaft roller and apply grease in bearing grease reservoir. Replace plug and tighten until grease appears at point A on both bearing assemblies REVISED 1977 SERVICE BULLETIN REFERENCES

3 SELF-PROPELLEDUPPER NEW BELT INSTALLATION Remove three screws and remove belt cover. Drive the pin from the left drive roller. Remove roller, washer, bearing and bushing assembly. NOTE The bushing has flat a surface matches the flat surface of When re-assembling, the must match. that the bracket. flat surfaces Slide belt through opening in bracket and under drive shaft. DO NOT twist belt. I ROLLER I WASHER BEARING AND PIN BUSHING ]

4 SELF-PROPELLED UPPER Seat belt in groove of driveshaft pulley and push belt through opening in shroud DO NOT TWIST BELT. I 1 Place belt over stationary pulley and around flywheel pulley. Depress idler pulley and slide belt in place. CORRECT BELT TENSION To set belt tension: Attach belt cover. CORRECT BELT INSTALLATION 1. Loosen the bolt holding stationary idler pulley. Using a 12" steel ruler as shown, adjust stationary idler pulley in bracket slot, so that top of pulley is flush to 1/16" below the top surface of flywheel pulley nut. Retighten idler pulley mounting bolt. 2. Position belt on pulleys correctly. DRIVE 90 TWIST SPRING LOADED IDLER SET STATIONARY IDLER FLUSH TO 1/16 BELOW TOP OF FLY- WHEEL NUT. \ I STATIONARY IDLER DRIVE SHAFT The self-propelled V belt is a SPECIAL BELT. Don't use a substitute. It won't work as well or as long SERVICE BULLETIN REFERENCES

5 BELT ALIGNMENT SELF=PROPELLED UPPER ALIGNMENT PROCEDURE See NOTE" NE X T PAGE REGARDING OLDER MOWERS " FROM MACHINED SURFACE OF LOWER DRIVEN (INSIDE EDGE OF THE 12" STEEL RULER) TO THE POINT WHERE THE BELT ENTERS THE GROOVE ON THE SPRING LOADED IDLER \ 1. Remove spark plug lead. Place control handle in Out-of-Drive position. 2. Set belt tension. Refer to page Examine driven pulley. If only one set screw is found and pulley cannot be secured properly, replace with double set screw driven pulley # Hold driveshaft so that all of the end play appears on the right side as shown in illustration. If excessive end play exists, refer to page for correction. 5. Using a 12" steel rule, adjust the lower driven pulley so that the machined surface on the left side of the pulley is 1/8" 5/32" from the edge of the belt ( NOTE: See note on next page for early model upper belt drive self-propelled mowers) at the point where the belt enters the groove on the spring loaded idler pulley. Tighten set screws on lower driven pulley securely. 6. Put mower IN-GEAR, raise handle to highest position. Maintain minimum a of 3/32" clearance between belt and tank flange. Also, check for adequate clearance between movable idler pulley and top of tank. If necessary,.loosen fuel tank mounting brackets and slide tank away from belt and/or pulley. Retighten bracket.

6 SELF-PROPELLED UPPER NOTE: EARLY PRODUCTION MOWERS The alignment procedure for early production upper belt drive self-propelled mowers specifies a measurement of 15/32" from machined surface of lower driven pulley to the point where the belt enters the groove on the spring loaded idler pulley. FIGURE 1 THIS BRACKET USED ON EARLY PRODUCTION MOWERS OLD STYLE BRACKET SMALL HALF MOON NO REINFO~EMENT RIB IF MOWER HAS OLD STYLE BRACKET USE 15/32" MEASUREMENT /32" FROM MACHINED SURFACE OF LOWER DRIVEN IlNSlDE EDGE OF THE 12' STEEL RULER) TO THE POINT WHERE THE BELT ENTERS THE GROOVE ON THE SPRING LOADED IDLER To determine early production mowers observe the brackethat mounts the stationary and movable idler pulleys. See Figures 1 and 2. THIS BRACKET USED ON LATER PRODUCTION MOWERS FIGURE 2 FORMED CORNERS SPRING LOADED IDLER NEW STYLE BRACKET LARGE HALF MOON RE~NFORC~MENT RIB IF MOWER HAS NEW STYLE BRACKET USE 1/8" TO 5/32" MEASUREMENT FOR IDLER BRACKET AND ASSEMBLY REPLACEMENT USE PART NO FOR ALL TOP BELT DRIVE MODELS DRIVESHAFT END PLAY There should only be sufficient end play in the driveshaft to allow the clutch assembly to pivot freely. To eliminate excessive end play proceed as follows: Applies particularly to models. 1. Remove the shoulder bolt and washers. See Illustration. wave 2. Reinstall shoulder bolt using sufficient spacers (plain or solid washers) until end play is obtained; or install replacement shoulder bolt P/N It is not necessary to replace wave washers removed in step Re-check belt for proper alignment.

7 SELF-PROPELLEDUPPER SERVICE CHECK LIST FOR UPPER BELT DRIVE SELF PROPELLED MOWERS 1. Check all parts on drive system. Replace any part that is worn, cracked or broken. 2. Spring-loaded idler arm must operate freely to follow engagement and disengagement. 3. Grommet no must be intact and without wear. Sand and other abrasive material will shorten its life substantially. 4. Check pulleys for wear, cracks or damage in v groove. Replace if necessary. 5. Belt must be free of oil and grease. 6. Make sure clutch control rod is properly adjusted for smooth operation. Check that brackets are secure on deck. 7. Check drive rollers for equal engagement to rear wheels. Three-sixteenths inch clearance recommended with drive disengaged. Is driveshaft bowed? 8. Check end-play on driveshaft. See page paragraph 2. Use spacer washers if needed. This applies especially to early production models; i.e Align lower driven pulley. Tighten set screws. Keep pulley well in deck clean. If necessary, install new drive pulley Part No which includes 2 set screws. 10. Check belt shield to shroud. If it interferes with belt, bend slightly to eliminate belt contact. Check belt cover for pulley interference. 11. Pulley bracket. Make sure the correct bracket and pulley assembly is installed. Models up to and including 8229 and 8229E use replacement Part No Models from 8229A, 8229B, 8229C, 8229D, 8229F and 8229EA use replacement Part No Correct tracking of belt from lower driven pulley to stationary idler pulley and idler pulley to upper drive pulley nut. 13. Belt and belt tension: Replace worn or thrown belt (could be cracked or stretched). 14. Lubrication: Lube driveshaft bearings. Drive bearings may wear shaft and cock lower drive pulley. 15. Vibration: Excessive vibration may throw loose belt. Reduce vibration by balancing blade and blade stiffener. Reinstall blade at 90 to piston with piston at top dead center. 16. If belt appears too long, check length. Correct length should be 35-1/2 inches 1/16 inch. 17. If all above points are correct, check operator and educate on correct operation. The cause may be twigs, pine needles, bushes, etc., getting into the drive system and throwing belt. Also, educate customer on proper clutching. Slip clutching, etc., can result in belt throwing. 18. If shrub or tree branches are causing belt to jump from flywheel nut pulley, a new improved belt cover, Part NO , may be installed to prevent this. SERVICE BULLETIN REFERENCES REVISED