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Snowmobile Belt Maintenance. Preventive maintenance and the application of some common sense rules can extend belt life dramatically. Snowmobile Belt.

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Presentation on theme: "Snowmobile Belt Maintenance. Preventive maintenance and the application of some common sense rules can extend belt life dramatically. Snowmobile Belt."— Presentation transcript:

1 Snowmobile Belt Maintenance

2 Preventive maintenance and the application of some common sense rules can extend belt life dramatically. Snowmobile Belt Maintenance Tips

3 A little attention to the belt on your sled can go a long way toward achieving the “maximum” life for your drive belt. Snowmobile Belt Maintenance Tips

4 Maximizing Belt Life Proper Belt Selection A belt that is either too long or too short will rob the drive system of efficiency. A short belt is the worst case scenario as it places high stress on the drive. Consult your dealer or the Carlisle snowmobile belt catalog for proper belt application.

5 Maximizing Belt Life Proper Installation Refer to the owner’s manual to ensure correct installation procedure and belt tension.

6 Maximizing Belt Life Belt “Break-In” Period Proper “break-in” of a new belt is important. In order to obtain maximum belt life, use half throttle for the first 30 miles.

7 Maximizing Belt Life Belt Storage If you are not going to install a new belt right away, or will have the belt removed for an extended period, be sure it’s kept in a cool, clean, dry environment until ready for use.

8 Maximizing Belt Life Belt Storage Snowmobile belts are sensitive to distortion and should never be hung from pins or racks. Leave the belt in its sleeve and store on a flat surface. Shelves are a good choice.

9 Maximizing Belt Life Correct Alignment Misalignment of the primary and secondary shafts and/or clutches will greatly reduce belt life. ProperImproperImproperImproper Alignment AlignmentAlignmentAlignment

10 Maximizing Belt Life Clutch Engagement Speed Drive belt wear can be accelerated when the engagement speed is set too high. Engagement speed on most production machines is set between 3500 and 5000 rpm. Consult your owner’s manual for the proper setting.

11 Maximizing Belt Life Avoid Contaminants The presence of oil or chemicals in contact with the belt drive system will reduce the life span and operational characteristics of the system. Lubzalot motor oil

12 Maximizing Belt Life Periodic Inspection Periodically inspect the entire drive system, belts and clutches. Any sign of excessive wear or damage indicates the need for replacements.

13 Problem Possible CauseSolution Uneven belt wear Clutch misalignmentAlign clutches on one side only Loose engine mountReplace or tighten engine mounts Rough, burred or Grind or polish pulleys damaged pulley surface Troubleshooting Drive Problems

14 ProblemPossible CauseSolution Belt Glazed ExcessivelyExcessive slippageCheck primary or Baked Appearancecaused by insufficientclutch for pressure on belt sidessmooth actuation Slippage caused byConsult dealer excessive horsepower (modified sleds) Excessive slippage from oilCheck bearing seals or moisture on pulley surfacesand clean pulley Insufficient pre-loadRepair/replace worn on secondary driven springout clutches. Weak or broken springs can cause insufficient pre-load Excessive operation in low gearInspect converter Troubleshooting Drive Problems Excessive glazing on a belt is an indicator of slippage

15 ProblemPossible CauseSolution Belt Worn ExcessivelyExcessive SlippageCheck primary clutch for in Top Widthsmooth actuation Rough, burred orGrind or damaged pulley surfacepolish pulleys Improper belt angleSee Carlisle catalog (incorrect belt forfor correct belt the application)application Considerable useSee Carlisle catalog (belt worn out)for replacement belt Troubleshooting Drive Problems top view of a top cog belt

16 ProblemPossible CauseSolution Belt Worn NarrowSecondary seizedRepair or replace in One Sectionor not functioningsecondary and replace properlybelt Excessive idle speedReduce idle speed and replace belt Excessive slippage inRotate track by hand primary caused byuntil free. Replace belt locked track. Track frozen to ground or problem with hyfax Troubleshooting Drive Problems A belt worn narrow in one section is commonly called “spin burn” or “hour glassing” and is a common failure mode. A distinctive sound can be heard as the burned section of the belt contacts the primary and secondary. Spin burn usually occurs on the primary clutch

17 ProblemPossible CauseSolution Excessive BeltExcessive engineReduce engine Tensionidle speed causingidle speed (at engine idle)the clutch to engage the belt Incorrect belt angleSee Carlisle catalog or length for correct belt Incorrect installationSee owners manual tensionfor correct tension Incorrect center distanceConsult dealer (common on modified sleds) Primary clutch bindingInspect primary clutch for damage Troubleshooting Drive Problems Commonly referred to as “creep”, it simply means the clutch is not disengaging from the belt when the engine is idling.

18 ProblemPossible CauseSolution Concave WornExcessive ride-outRepair or Belt Sides on primary clutchreplace primary Drive misalignmentAlign clutches Rough, burred orGrind or damaged pulleypolish pulley surface Excessive slippageRepair or replace primary clutch Troubleshooting Drive Problems When installing a belt make sure the ride position of the belt is at or below the outside circumference of the secondary clutch. This will eliminate concaved sides and transmit the maximum horsepower from the primary (driver) to the secondary (driven) clutch.

19 ProblemPossible CauseSolution Belt DisintegrationExcessive beltReduce engine speedrpm at high speed Clutch misalignmentAlign clutches causing belt roll-over Excessive slippage/Inspect converter heat build up in belt Excessive operationInspect converter in low gear Troubleshooting Drive Problems Belt disintegration is the result of major abuse or lack of maintenance. A pre-ride checklist should include checking the drive belt for loose cords, cracks, or defects.

20 ProblemPossible CauseSolution Belt Roll-Over Pulley misalignmentAlign pulleys at high speed Excessive belt speedReduce engine RPM Excessive ride-outRepair or replace on primary clutchdriver pulley Incorrect belt lengthSee Carlisle catalog for correct belt Troubleshooting Drive Problems Belt roll-over (not to be confused with “sled” roll-over as demonstrated in the picture here) normally results in total destruction of the belt. Because rubber has a memory, belts built in an inverted manner tend to revert to their original position, upside down. This is a classic cause of belt roll-over. Carlisle snowmobile belts are built in an upright position to avoid this phenomenon. Skiving (bevel cutting) the top portion of the belt also dramatically reduces belt roll-over and laminate separation.

21 ProblemPossible CauseSolution Belt Edge Pulley misalignmentAlign pulleys Cord Broken Improper belt installationSee owner’s manual Excessive idle speedReduce idle speed (belt engaging clutch) Excessive pre-loadSee owner’s manual on secondary clutchand adjust to correct pre-load Troubleshooting Drive Problems The cords or “tensile members” are the load carrying element of the belt. Cord “pop-out” (cord exiting the sidewall of the belt) is the most common failure mode with snowmobile drive belts. The largest contributor to this failure is excessive sidewall pressure and pulley misalignment. Most manufacturers recommend 15 to 18 pounds of preload to the secondary.

22 ProblemPossible CauseSolution Flex Cracks Considerable use,See Carlisle catalog Between Cogsbelt worn outfor replacement belt Bent pulley flangeRepair or replace causing belt distortionpulleys Excessive operation inInspect entire low geardrive system Operation in extremelyWarm up belt slowly low temperaturebefore operating environmentsled Troubleshooting Drive Problems One of the most common causes of cracking (inside circumference) is flexing of the belt during extremely cold weather. If you are not able to take the sled/belt inside at night, at least let the engine compartment warm up the belt before taking off on in extremely cold weather.

23 ProblemPossible CauseSolution Sheared CogsImproper beltSee owner’s manual installation Belt rubbingCheck drive components stationary objectand remove obstacle Primary clutch bindingInspect primary clutch for damage Troubleshooting Drive Problems Belts are designed to operate in the same position they are built, right side up. Never turn a belt inside out for inspection (or any reason). This has an adverse effect on the components of the belt and could result in a reduction of drive belt life.

24 ProblemPossible CauseSolution Broken BeltEngagement speedReduce engine (RPM) too highengagement speed Belt hanging up onWrong belt (too short) bottom of secondaryReplace with correct belt Locked TrackRotate track by hand until free Troubleshooting Drive Problems Belt shock loading often causes breakage. Shock loading can be caused by excessively high engagement RPM, a too short belt (binding on the bottom of secondary) or by a locked track.

25 Drive System Terms Drive Belt — variable speed belt linking driver and driven clutches. The belt’s side angles must correspond to the pulley face angles of both clutches and its top width must correspond to that width which is required by the pulley design. The belt contains helically wound tensile members for strength and is cogged for greater flexibility as it operates throughout the driver and driven clutches shift in pitch diameter.

26 Drive System Terms Center Distance (C.D.) — the exact measurement between center of crankshaft to center of jackshaft, which is used as a reference to assure correct set-up, when considering a specific belt O.C. and any particular driver and driven pair’s diameters. There is only one correct center distance for any given driver, driven and belt drive layout.

27 Drive System Terms Jackshaft — the auxiliary or countershaft parallel to the engine’s PTO shaft and onto which the driven clutch is mounted, in-line with the driver.

28 Drive System Terms Movable Face — (variable pitch pulley) the sheave face (pulley half) of both driver and driven clutch that shifts position to allow change of “pitch diameter” and thus change of ratio. engine side fixedmoveable

29 Drive System Terms Primary (driver clutch) — “centrifugally-activated” clutch mounted on engine PTO shaft which squeezes the belt to various larger diameters from its initial small diameter at idle and thereby causes the vehicle to tend to go correspondingly faster. Primary Clutch

30 Drive System Terms Secondary (driven clutch) — the variable pitch “torque sensitive” pulley mounted on a driven shaft (jackshaft, countershaft) and in-line with the driver. Larger in diameter than the driver and frequently called the torque converter, its greater diameter multiplies available torque, that results in a corresponding reduction in RPM…of the vehicle’s driving wheel/s….in relation to the RPM of the engine. Secondary

31 Drive System Terms Secondary (driven clutch) Its combination compression/torsion spring together with the mechanical advantage of its “cams” give it the ability to both “respond to” and also to “over-ride” the centrifugally controlled driver clutch and thereby achieve (shift to) a torque multiplication ratio that, at any given moment, is a balance between the engine’s power and the torque requirements of changing vehicle load and/or terrain.

32 Drive System Terms Sheaves — The pulley faces. Two sheaves form a pulley. The moveable sheave is the pulley face that is moved in and out to create different pitch diameters for the drive belt. Both driver and driven clutch have moveable sheaves. The stationary sheave is the pulley face that remains in place as moveable sheave changes position to create various pitch diameters. fixed sheave moveable sheave engine side

33 Drive System Terms Torque Converter consists of two “variable pitch pulleys” linked by a special type of belt and all working in a harmonious relationship. The “system’s” function can be likened to the automatic transmission in a car and is often called a “ torque converter system”.

34 Drive System Terms Variable pitch pulley — a pulley whose halves are able to spread apart and/or close together to vary correspondingly the diameter at which a belt is carried in the pulley. fixedmoveable

35 Drive System Terms Ride-Out — plus or positive ride position. Ride position is the radial distance from the top of a belt in a sheave groove to the outside diameter of the sheave. correct ride position ride-out position

36 The average snowmobiler puts 1500 miles per year on his sled. Carlisle annually logs over a million miles in product field testing. This includes sleds made by all the major OEM manufacturers. This extensive testing helps to ensure our confidence in the dimensional criteria, durability and high performance of our belts.

37 Carlisle - The world’s leading supplier of snowmobile drive belts !

38 Tel: +44 1327 701030 Fax: +44 1327 701031 from

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