BOSFLAG mower spindle kit 3-pack with pulley and belt — fits Toro/Exmark, full deck rebuild

BOSFLAG 3PK 139-3214 spindle kit is a complete replacement set including three spindle assemblies, three spindle pulleys, three idler pulleys, one deck belt and matching hardware for compatible Toro and Exmark riding mowers.

This three-pack service kit is built to restore proper deck rotation and belt tracking on several Toro Zs, SS and MX series machines and many Exmark models. It bundles the common wear parts you would replace when performing a full mower-deck overhaul: spindle housings with bearings, spindle pulleys that mount to the blade shafts, idler pulleys with hardware, plus a full-length deck belt sized to fit the listed machines. The kit is intended for routine maintenance or multi-deck servicing where replacing all spindles and pulleys at once reduces downtime and avoids repeated labor.

Which machines will these parts fit?

These BOSFLAG components are made to match OEM dimensions for many Toro and Exmark commercial and residential models. Verify your machine part numbers before ordering to ensure compatibility.

• Fits Toro Zs 5000tf, Zs 5000, Swx 5050 and Sw 5000 families (multiple chassis and part-number references listed).
• Compatible with Toro SS and MX series machines referenced in the product listing.
• Also fits a range of Exmark Quest and related models that share the same pulley and spindle dimensions.

How do these parts improve mower deck performance?

Replacing worn spindles, pulleys and the belt restores smooth blade rotation and consistent cutting height by removing play and friction from the drive system. The complete kit addresses multiple failure points at once, reducing the chance of repeat problems after a single repair session.

• New spindle bearings reduce wobble and uneven blade wear.
• Correct-dimension pulleys ensure proper belt tracking and tension.
• Fresh belt removes glazing and stretch that cause slipping under load.
• Included hardware simplifies installation and secures idler pulleys correctly.

What are the key specifications I should know before buying?

The kit pairs specific replacement numbers and measured dimensions so you can cross-reference with your machine or old parts. Check the pulley and belt sizes against your existing components to confirm a match.

• Spindle assembly: BOSFLAG 139-3214, replaces Toro 139-3214 and similar OEM references.
• Spindle pulley: 125-5575 spec — height 0.84", bore 0.66", outside diameter 5.04".
• Idler pulley: 106-2175 style with included hex bolt, washer and flanged nylon lock nut.
• Belt: replacement for Toro 119-8820 — width 1/2", length 142".

How should I use this kit during maintenance?

This three-pack is designed for either full-deck rebuilds or servicing multiple machines. Replace spindles and pulleys in matched sets and fit the new belt per your mower’s belt routing diagram to ensure correct tension and alignment.

• Remove blades, old pulleys and belts; inspect deck and blade spindles for damage.
• Install spindle assemblies and torque to manufacturer spec; mount pulleys and idler hardware included.
• Route and tension the 142" belt per service manual; test spin and check for noise or wobble.
• Perform a short test mow and re-check fasteners and belt alignment.

Who is this for: This BOSFLAG 3PK replacement kit is suited for owners, fleet managers, and maintenance shops that service Toro and compatible Exmark riding mowers. It’s ideal when multiple spindle failures are evident, when performing preventative full-deck servicing, or when you want matching parts across several machines to minimize future downtime. Confirm fitment with your model and part numbers before purchase to ensure proper installation.