💰 Annual Savings: Aftermarket belts save $20–$35 each. Change 2 belts per season = $40–$70 saved annually. Over 5 years: $200–$350 savings with identical performance.

📋 Measurement — Step by Step

1. Remove old belt carefully — release tension at idler pulley or tension spring. Photograph belt routing path before removal — critical for reinstallation
2. Measure inside circumference — lay belt flat on floor in natural position. Use cloth measuring tape on INSIDE edge. Do NOT stretch belt during measurement. Round to nearest whole inch
3. Measure belt width at top surface — use calipers or ruler. Most Caroni mowers use 1/2″ (A-section). In millimeters: 13mm = 1/2″, 17mm = 5/8″
4. Cross-reference belt size — order by [Width] x [Length]. Example: “1/2 x 90” → A90, 4L900, or AX90 depending on brand

📋 Replacement — Step by Step

1. Release belt tension — disconnect PTO. Loosen idler pulley adjustment bolt or compress spring-loaded tensioner. Belt should have slack for easy removal — never force belt off tight pulleys
2. Remove old belt and photograph routing — note which side of idler belt contacts, where it wraps around tensioner pulleys. Save old belt for reference
3. Clean and inspect all pulleys — remove debris from grooves with wire brush or compressed air. Check for cracks, chips, and wear. Verify pulleys spin freely — seized bearings cause belt overheating. Check alignment with straight edge — even 1/8″ misalignment destroys a new belt in 20–30 hours
4. Install new belt following routing photo — start at driven pulley (gearbox), work toward drive pulley (PTO). Seat belt fully into each V-groove — belt should sit at the bottom, not riding high on pulley sides
5. Adjust tension and break in properly — set 1/2″ deflection when pressing belt midway between pulleys with 10 lbs force. Apply belt dressing spray. Re-tension after first 5 hours then at 10 hours

• Correct: 1/2″ deflection with 10 lbs pressure midway between pulleys
• Too tight (less than 1/4″): bearing failure, belt cracking, excessive heat
• Too loose (more than 3/4″): slipping, squealing, overheating, glazing

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

Fix: Reduce tension to 1/2″ deflection spec. Check pulley alignment with straight edge. Replace damaged pulleys. Verify clearance around belt (1/2″ minimum). Typical belt life is 150–300 hours — if failing under 100 hours find and fix root cause first.

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

Fix: Increase tension to spec. Clean pulleys and belt with degreaser. Apply belt dressing spray. Replace glazed belts immediately — glazing is permanent damage. If properly tensioned but still slipping, the belt is worn out.

Causes: Pulley misalignment (most common), bent pulley shaft, damaged pulley groove, belt running on pulley edge instead of groove.

Fix: 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 — should be equal. Even 1/8″ misalignment destroys belt in 20–30 hours.

Causes: Severe misalignment, insufficient tension, worn pulley grooves, debris in pulley, wrong belt size (too long), pulley wobble from bad bearings.

Fix: Fix alignment immediately. Increase tension. Replace worn pulleys — V-groove should have crisp 38° angle. Clean all debris. Test pulleys for wobble by spinning — more than 1/16″ runout requires bearing replacement.