Multiquip 9900374000 Complete Seal Kit (Shaft & Back End)

The Multiquip 9900374000 is a genuine OEM Complete Seal Kit (Shaft & Back End) designed for HTX44 and STX55 series hydrostatic ride-on power trowels. As a direct Multiquip OEM replacement, this kit delivers the same sealing materials, dimensions, and performance characteristics as the original components installed at the factory. Confirmed fitment includes the HTX44K4, HTX44K5, HTX44Y4, HTX44Y5, and STX55J6 — always verify your model code before ordering to ensure a correct match.

Key Features

• Genuine OEM Sealing Integrity — Manufactured to Multiquip OEM specification, ensuring correct material durometer and compression characteristics for hydraulic and shaft sealing on hydrostatic trowel drives.
• Complete Shaft & Back End Coverage — A single kit addresses both shaft seals and back end seals, so you can perform a thorough reseal in one service event without sourcing individual components separately.
• Confirmed HTX44 & STX55 Fitment — Directly fits HTX44K4, HTX44K5, HTX44Y4, HTX44Y5, and STX55J6 hydrostatic ride-on power trowels; verify your model code prior to purchase.
• Prevents Hydraulic Fluid Loss — Worn or damaged shaft seals allow hydraulic fluid to escape the drive system, causing loss of blade pitch control and erratic trowel behavior. Fresh seals restore consistent hydraulic pressure throughout the system.
• Part Number 9900374000 for Accurate Ordering — Using the correct Multiquip part number eliminates the risk of receiving a mismatched seal kit that could fail prematurely or require rework.

The shaft and back end seals in a hydrostatic ride-on trowel form a critical barrier that keeps hydraulic fluid contained within the drive and blade-pitch control circuits. When these seals degrade — through heat cycling, age, or contamination — fluid bypasses the sealing surfaces, leading to sluggish or unresponsive blade pitch adjustment and potential damage to hydraulic components. Replacing the seals with a complete kit like the Multiquip 9900374000 restores the hydraulic system's ability to hold pressure consistently, which is essential for smooth, controlled finishing passes on a concrete slab.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.