BOSFLAG GY20629 Idler Pulley 2-Pack for John Deere & Cub Cadet Decks — 5.23" OD, Includes 3/8"-16 + M10 Lock Nuts

The BOSFLAG 2-pack GY20629 idler pulleys are precision replacement pulleys designed to restore smooth belt tracking and reliable deck operation on compatible John Deere and Cub Cadet lawn tractors.

These aftermarket idler pulleys match critical dimensions and include two lock-nut options to simplify installation across a wide range of mower deck setups. Machined bearing seats and a balanced wheel profile help reduce vibration and promote consistent belt tension, making these pulleys a practical option for routine deck maintenance or mid-season repairs.

Will these pulleys fit my John Deere or Cub Cadet mower?

Yes — the BOSFLAG GY20629 pulleys are made to fit many common John Deere and Cub Cadet models by matching the original equipment dimensions and mounting hardware requirements. Check the pulley height, outer diameter, and inner bore against your existing part to confirm compatibility.

• Compatible with multiple John Deere series (e.g., D100, X100, LA, and Z-series models).
• Works with Cub Cadet models including XT1, XT2, RZT and similar decks.
• Compare dimensions: height 1.67" • OD 5.23" • ID 0.66" to your existing pulley.
• Includes 3/8"-16 and M10 flanged nylon lock nut options for different mounting studs.

How does the pulley design affect mower deck performance?

Properly sized and balanced idler pulleys keep the belt aligned and under consistent tension, which reduces slippage and uneven wear on blades and belts. BOSFLAG pulleys have precision-machined surfaces to support steady rotation and minimize vibration during normal mowing conditions.

• Balanced wheel profile cuts vibration and belt chatter.
• Machined bearing seat for smooth rotation and less heat buildup.
• Durable outer surface sustains consistent belt contact area.
• Two lock-nut choices secure the pulley to common stud sizes.

What are the exact dimensions and included hardware?

Knowing the pulley measurements speeds up verification and helps avoid returns. The BOSFLAG GY20629 pulleys are specified to match common OEM sizes so they install without modification on the listed tractors.

• Pulley height: 1.67 inches.
• Outer diameter (OD): 5.23 inches.
• Inner diameter (ID/bore): 0.66 inches.
• Hardware: includes both 3/8"-16 flanged nylon lock nut and M10 flanged nylon lock nut.

How easy is installation and what should I check during replacement?

Installation is straightforward for anyone familiar with basic mower maintenance; most pulleys are swapped with simple hand tools. Before final reassembly, inspect the belt for cracks, check spindle studs for straightness, and confirm the new pulley spins freely without wobble.

• Remove old pulley and clean mounting area of debris and rust.
• Confirm stud diameter and use the supplied matching lock nut.
• Spin the pulley by hand to check for smooth rotation before tightening.
• Re-route belt and test deck engagement at low throttle first.

Who is this for: The BOSFLAG GY20629 2-pack is aimed at homeowners, landscape pros, and small-engine repair technicians who need an affordable, accurately sized replacement pulley for John Deere and Cub Cadet mower decks. It’s useful for seasonal tune-ups, replacing noisy or worn idlers, and keeping older tractors running reliably without sourcing OEM parts.