Spindle Assembly 037-4000-00 / 037-8000-00 with 033-6006-00 Pulley for Bad Boy 54-Inch Deck

Overview

This aftermarket 037-4000-00 / 037-8000-00 spindle assembly with 033-6006-00 pulley is a replacement-style mower deck spindle and pulley package for select Bad Boy 54-inch mower deck applications.

Key Features

• Aftermarket replacement-style Bad Boy mower deck spindle and pulley package
• Product Type: Spindle Assembly
• Lead Spindle Numbers: 037-4000-00, 037-8000-00
• Also Replaces: 037-4000-50, 038-4000-50, 037-8000-50
• Spindle Pulley Number: 033-6006-00
• Common Deck Reference: 54 inch
• Built around Bad Boy spindle and pulley part numbers first to reduce fitment confusion

Compatible Brands & Model Series

This 037-4000-00 / 037-8000-00 spindle assembly with 033-6006-00 pulley is associated with select Bad Boy 54-inch mower deck applications using the listed spindle and pulley path.

Supplier model references include:

• Bad Boy Rebel 54-inch, 2019 through 2023
• Bad Boy Outlaw and Outlaw Extreme 54-inch, 2017 through 2018
• Bad Boy Outlaw XP 54-inch, 2017 through 2018
• Bad Boy Stand-On 54-inch, 2017
• Bad Boy Maverick HD 54-inch, 2022 through 2023
• Bad Boy Walk Behind 54-inch, 2023

Verify your part numbers before ordering.

Replaces OEM Part Numbers

• Bad Boy Spindle Assembly Numbers: 037-4000-00, 037-8000-00, 037-4000-50, 038-4000-50, 037-8000-50
• Bad Boy Spindle Pulley Number: 033-6006-00

Part Number Breakdown

Part numbers below are grouped by component type. This fixed package includes the spindle assembly and pulley shown below.

• Spindle / Mandrel Numbers: 037-4000-00, 037400000, 037-8000-00, 037800000, 037-4000-50, 037400050, 038-4000-50, 038400050, 037-8000-50, 037800050
• Spindle Pulley Numbers: 033-6006-00, 033600600

Spindle Specifications

• Spindle Numbers: 037-4000-00, 037-8000-00, 037-4000-50, 038-4000-50, 037-8000-50
• Height Reference: 7.63 inches to 7.67 inches depending on supplier measurement point
• Material Reference: aluminum and steel spindle path
• Deck Size Reference: 54 inch
• Application Note: Confirm spindle height, mounting pattern, shaft setup, pulley fit, and belt routing before ordering

Pulley Specifications

• Spindle Pulley Number: 033-6006-00
• Pulley Note: Match the pulley number, pulley diameter, bore, groove style, and belt path before ordering.
• Finish Note: Pulley finish or color may vary by supplier batch. Match the part number, dimensions, and belt path instead of ordering by color.

Common Symptoms / When to Replace

• Mower deck spindle is noisy, loose, seized, or wobbling
• Blade has excessive play at the spindle shaft
• Deck vibration increases during blade engagement
• Spindle pulley is worn, damaged, bent, or no longer tracking the belt correctly
• Original spindle or pulley number matches the listed Bad Boy replacement path

Quick Ship Fulfillment

This item may ship directly from one of our trusted U.S. distribution partners to help reduce transit time. Packaging, labeling, or warehouse origin may vary, but the part will match the replacement numbers, fitment notes, and specifications shown in this listing.

Why Buy From PTO Direct USA

• Fitment-first product organization by Bad Boy spindle part-number path
• Clear separation between spindle and pulley references
• Clean single-package listing without unrelated blade or pulley paths
• U.S.-focused fulfillment options for faster delivery when available

Need a Custom Package?

Need a different combination of parts? Email us the part type and part numbers you need, such as spindle assemblies, blades, belts, pulleys, reinforcement rings, bearings, or hardware. We can review the part-number path and quote a custom package when available.

FAQ

Is this an OEM Bad Boy spindle assembly?

No. This is an aftermarket replacement-style spindle and pulley package intended to replace the listed Bad Boy part-number path when the physical fitment details match.

What are the lead spindle numbers for this listing?

The lead spindle numbers are 037-4000-00 and 037-8000-00. This listing also references 037-4000-50, 038-4000-50, and 037-8000-50.

Is 033-6006-00 a spindle number?

No. 033-6006-00 is the spindle pulley number and should stay in the pulley bucket.

Does this listing include a blade?

No. This listing includes 1 spindle assembly and 1 spindle pulley only, unless the product image shows otherwise.

Can I order by deck size only?

No. Deck size alone is not enough. Match the original spindle number first, then confirm pulley number, mower model, deck layout, mounting pattern, shaft setup, and belt routing before ordering.