TC Series (Standard Finish Mowers)

• TC590N (5.9 ft / 1.8m), TC710N (7.1 ft / 2.2m)
• Standard PTO speed: 540 RPM
• Typical belt: 1/2″ x 88-92″ (A88-A92 or 4L880-4L920)
• Single belt drive from PTO to gearbox

TM Series (Heavy-Duty Models)

• TM1640 (6.5 ft), TM1900 (7.8 ft / 2.35m)
• Reinforced gearbox and deck construction
• Typical belt: 1/2″ x 90-95″ (A90-A95 or 4L900-4L950)
• Higher horsepower capacity (40-60 HP)

SR Series (Slope Mowers)

• SR1300 (4.3 ft), SR1700 (5.6 ft) – specialty applications
• Low center of gravity for hillside mowing
• May use different belt configurations or dual belts
• Verify model-specific belt requirements

💰 Annual Savings Calculator: Aftermarket belts save $20-35 each. Change 2 belts per season (spring + mid-season replacement) = $40-70 saved annually. Over 5 years: $200-350 savings with identical performance and reliability!

Classical Sizing (A, B, C Section)

Format: Letter + Number (e.g., “A90”)

Letter: Belt cross-section width (A = 1/2″, B = 5/8″, C = 7/8″)

Number: Inside circumference in inches (A90 = 1/2″ wide, 90″ inside length)

Fractional HP Sizing (4L Series)

Format: “4L” + Number (e.g., “4L900”)

4L prefix: Fractional horsepower belt, 1/2″ top width

Number: Length in tenths of inch (4L900 = 90.0″ inside length)

Premium/Wrapped Belt Codes (AX, BX)

Format: Letter + “X” + Number (e.g., “AX90”)

“X” designation: Premium wrapped construction (Gates Hi-Power, etc.)

Performance: 2-3x longer life than standard belts in agricultural applications

💡 Conversion Example: A Caroni mower requiring a “1/2 x 90″ belt” can use: A90 (classical), 4L900 (fractional), AX90 (premium wrapped), or any belt marked “1/2″ x 90″ inside circumference”. These are all the same belt with different naming systems!

🔴 Problem: Belt Keeps Breaking/Cracking

Causes: Over-tensioning (most common – crushes belt internally), misaligned pulleys, damaged pulleys with sharp edges, belt rubbing on guards/brackets, wrong belt size, excessive heat

Solutions: Reduce tension to proper spec (1/2″ deflection). Check pulley alignment with straight edge. Replace damaged pulleys. Verify adequate clearance around belt (1/2″ minimum). Ensure proper belt size – too short = over-stressed. Typical belt life: 150-300 hours. If failing under 100 hours, tension too high.

🟡 Problem: Belt Slipping (Squealing/Smoking)

Causes: Insufficient tension, oil/grease contamination on belt or pulleys, glazed belt surface (shiny = slipping damage), worn belt (stretched beyond adjustment), overload conditions

Solutions: Increase tension to spec. Clean pulleys and belt with degreaser (replace belt if oil-soaked – cannot be cleaned effectively). Apply belt dressing spray. Replace glazed belts immediately (glazing = permanent damage). Reduce cutting load – don’t cut too thick/fast. If belt properly tensioned but still slipping = belt worn out, replace.

🔵 Problem: Belt Wears on One Side/Edge

Causes: Pulley misalignment (most common), bent pulley shaft, damaged pulley groove, belt running on pulley edge instead of groove, frame/mounting damage causing misalignment

Solutions: Check alignment using straight edge across all pulley faces – should be within 1/16″ across entire belt path. Measure pulley-to-pulley distance on both sides of belt – should be equal. Replace bent shafts. Shim pulleys to correct alignment. Address frame damage causing misalignment. Even 1/8″ misalignment destroys belt in 20-30 hours.

🟣 Problem: Belt Throws Off Pulleys

Causes: Severe misalignment, insufficient tension, damaged/worn pulley grooves, debris in pulley preventing proper seating, wrong belt size (too long), pulley wobble from bad bearings

Solutions: Fix alignment immediately. Increase tension. Replace worn pulleys (V-groove should have crisp 38° angle). Clean all debris. Verify correct belt size. Test pulleys for wobble by spinning – more than 1/16″ runout requires bearing replacement. Install belt guides/keepers if mower vibration severe.

Why does my Caroni mower belt keep breaking?

Most common causes in order of frequency: (1) Over-tensioning – most belts are over-tightened, causing internal cord damage and premature cracking. Belt should have 1/2″ deflection when pressed with 10 lbs force, not drum-tight. (2) Misaligned pulleys – even 1/8″ misalignment causes edge wear and failure within 20-30 hours. (3) Damaged pulleys – sharp edges from worn pulley grooves cut into belt. (4) Belt rubbing on guards or frame – inspect entire belt path for contact points. (5) Wrong belt size – too short creates excessive stress. Proper belt life should be 150-300 hours. If failing under 100 hours, find and fix root cause before replacing belt again.

Can I use automotive V-belts on my Caroni mower?

NO – do not use automotive V-belts or serpentine belts on agricultural equipment. Caroni mowers require wrapped or cogged agricultural/industrial V-belts with specific construction: heat resistance for outdoor use in 100°F+ temperatures, oil resistance from grass/debris/hydraulic fluid exposure, higher flexibility for clutching applications and smaller pulley diameters, UV resistance for sun exposure, and reinforcement for shock loads from blade strikes. Use only: Gates Hi-Power II, PIX Agricultural, Jason Industrial, or equivalent ag-rated V-belts. Automotive belts will fail within days from heat/oil damage. The $10 savings isn’t worth the breakdown.

How tight should my Caroni mower belt be?

Proper tension: 1/2″ deflection when pressing belt midway between pulleys with 10 lbs force. Use belt tension gauge for accuracy ($15-25 tool). Testing by hand: press belt with thumb – should move 1/2″ with moderate pressure, not stay rigid. Too tight (less than 1/4″ deflection) causes: premature bearing failure in pulleys and gearbox ($80-200 repair), belt cord breakage from over-stress, excessive heat generation, cracking in belt sidewalls. Too loose (more than 3/4″ deflection) causes: belt slipping under load, squealing noise, overheating from friction, glazing (shiny surface = destroyed belt), reduced power transfer to blades. Re-tension after first 5 hours of operation (new belts stretch), then every 25 hours or when slipping occurs.

What’s the difference between A90 and 4L900 belts?

They’re the same belt with different naming conventions. A90 uses “classical” sizing (A-section = 1/2″ wide, 90 = 90″ inside circumference). 4L900 uses “fractional HP” sizing (4L = fractional HP belt 1/2″ wide, 900 = 90.0″ in tenths of inch). Both specify: 1/2″ top width, 90″ inside circumference, identical cross-section profile. Interchangeable completely – buy whichever is cheaper or available. Other equivalent codes: AX90 (Gates premium wrapped), 1/2″ x 90″ (generic description). All fit identical pulley systems. Only difference may be construction quality between standard (A90/4L900) and premium wrapped (AX90) versions – wrapped lasts 2-3x longer in agricultural use.

How long should a Caroni mower belt last?

Expected belt life varies by conditions: Clean grass, proper tension, good alignment = 200-300 hours. Dusty/sandy conditions = 150-200 hours (abrasive particles wear belt faster). Heavy use (thick grass, all-day mowing) = 150-250 hours. Light residential use = 300-400 hours possible. Premium wrapped belts (Gates AX, etc.) = 400-600 hours in ideal conditions. Belt life indicators – replace when: visible cracks in sidewalls, fraying on edges, glazed/shiny appearance (from slipping), wear on one side (misalignment damage), belt stretched beyond tension adjustment. Pro tip: track hours on belt with logbook – replace proactively at 200 hours rather than waiting for failure during busy season. Keep spare belt on hand – $25 belt vs. lost mowing time worth hundreds.