918-04126B Spindle Assembly for Cub Cadet, MTD & Troy-Bilt Decks

Overview

This 918-04126B spindle assembly is a replacement mower deck spindle for select Cub Cadet, MTD, Troy-Bilt, Massey Ferguson, Toro, and related MTD-built mower deck applications using the listed spindle replacement numbers.

This spindle is commonly used on mower decks replacing 618-04126, 918-04125, 918-04126, or 918-04126B.

Key Specs

• Part type: mower deck spindle assembly
• Primary replacement number: 918-04126B
• Pulley diameter: 5-3/4 inches
• Blade mount: 6-point star center hole style
• Deck application: select MTD-built mower decks using the listed spindle numbers
• Quantity included: 1 spindle assembly

Compatible Brands & Model Series

This spindle assembly is intended for select MTD-built mower decks using the listed OEM replacement numbers.

• Cub Cadet: select LT, RZT, RZT 50, and related mower deck applications using the 618-04126 / 918-04126 spindle path. For the full RZT 50 deck parts route, see the Cub Cadet RZT 50 Parts Guide.
• MTD: select mower decks using 618-04126, 918-04125, or 918-04126 series spindle numbers
• Troy-Bilt: select mower decks using the listed spindle numbers
• Massey Ferguson: select applications using 618-04126 or 918-04125 spindle numbers
• Toro: select applications replacing 1120370

Fitment note: Supplier data references both 50-inch deck applications and some 42-inch Cub Cadet / Troy-Bilt deck paths. Match the original spindle number and blade center style before ordering.

Replaces OEM Spindle Assembly Numbers

• Cub Cadet: 618-04126, 618-04126A, 918-04125, 918-04125B, 918-04126, 918-04126A, 918-04126B
• MTD: 618-04126, 618-04126A, 918-014126, 918-04125, 918-04125A, 918-04125B, 918-04126, 918-04126A, 918-04126B
• Troy-Bilt: 618-04126, 618-04126A, 918-04125, 918-04125B, 918-04126, 918-04126A
• Massey Ferguson: 618-04126, 618-04126A, 918-04125, 918-04125B
• Toro: 1120370

Important Fitment Check

Before ordering this spindle assembly, compare your original spindle to the listed replacement numbers and confirm:

• Your original spindle number matches 618-04126, 918-04125, 918-04126, 918-04126B, or a listed cross-reference
• Your deck uses the correct spindle mounting pattern
• Your blade uses the correct 6-point star center hole style
• Your pulley diameter matches the required deck setup
• Your mower model and deck size match the correct MTD-built deck path
• Your belt, blade, and pulley setup match this spindle assembly

Many MTD-built decks look similar but use different spindle assemblies, blade center styles, and pulley setups.

Working on a Cub Cadet RZT 50? This 918-04126B spindle assembly is part of the confirmed 50-inch deck parts path covered in our Cub Cadet RZT 50 Parts Guide, along with the matching deck belt, blades, idler pulley, PTO clutch, and full deck rebuild kit.

Before Ordering

• Check the original spindle number if it is stamped or listed in your mower parts diagram
• Confirm deck size and blade count
• Confirm the blade center hole style before ordering
• Inspect your spindle pulley and deck belt for wear
• Replace all worn spindles, pulleys, blades, and belts together when needed
• Do not rely on mower color, deck appearance, or brand name alone

Common Symptoms This Spindle Helps Fix

• Noisy mower deck spindle
• Blade wobble or vibration
• Uneven cut quality
• Grinding or squealing from the deck
• Loose or damaged spindle shaft
• Blade not spinning smoothly
• Premature belt wear caused by spindle drag or pulley misalignment

Installation Notes

• Disconnect the spark plug and remove the key before servicing the mower deck
• Take photos of the deck belt routing before disassembly
• Inspect the blade, pulley, belt, and mounting hardware during spindle replacement
• Make sure the spindle seats flat against the mower deck
• Torque blade and mounting hardware to the mower manufacturer’s specification
• Rotate the blade by hand after installation to confirm smooth movement

What’s Included

• 1 spindle assembly

Quantity note: This listing includes one spindle assembly. Many multi-blade mower decks use more than one spindle. Order the quantity needed for your repair.

Why Buy From PTO Direct USA?

• Fitment-first deck part listings
• Clear OEM and aftermarket part-number routing
• Fast USA shipping
• Support for mower owners, repair shops, and small-engine dealers
• Related belts, blades, pulleys, deck kits, and PTO clutches available

Need Help Confirming Fitment?

If you are unsure whether this spindle fits your mower, send us your mower model number, deck size, original spindle number, blade center style, and photos of your existing spindle before ordering.

FAQ

Does this replace 918-04126B?

Yes. This spindle assembly replaces 918-04126B and related spindle numbers including 618-04126, 918-04125, 918-04126, and 918-04126A.

Does this fit Cub Cadet RZT 50?

This spindle is listed for select Cub Cadet RZT 50 and related MTD-built deck applications using the 618-04126 / 918-04126 spindle path. Confirm your original spindle number, blade center style, mounting pattern, pulley diameter, and deck layout before ordering. For the full 50-inch deck parts route, see the Cub Cadet RZT 50 Parts Guide.

Does this fit Troy-Bilt decks?

This spindle is listed for select Troy-Bilt mower decks using 618-04126, 918-04125, or related spindle replacement numbers.

What blade center style does this spindle use?

This spindle is listed with a 6-point star center hole blade mount style. Confirm your blade center style before ordering.

How many spindle assemblies are included?

This listing includes one spindle assembly. If your mower deck uses multiple spindles, order the quantity required for your repair.

Can I order this spindle by deck size only?

No. Do not order by deck size alone. Match your original spindle number, blade center style, pulley setup, mounting pattern, and mower model before ordering.

Need the full deck setup? View the related 50-inch deck rebuild kit for Cub Cadet RZT 50, MTD, and Troy-Bilt.

Need matching deck parts? Browse mower deck belts, mower blades, spindle assemblies, and deck pulleys and idlers.