6659564 6670667 6677666 Final Drive for Bobcat 331 334 425 428 | TM04I Travel Motor (9-Hole 204mm)

Heavy 4200 N·m Torque & 204mm Spigot Fitment for 3.0–4.0T Bobcat Earthmovers. Direct OEM replacement TM04I dual-displacement hydraulic travel motor complete with 52.7:1 planetary reduction gearbox, engineered specifically for 9-hole 204mm register Bobcat 331, 331 C, 331 D, 334 D, 425, and 428 mini excavators.

1. Technical Operating Specifications

(Authority verified via Bobcat parts cross-reference & compact hydraulic engineering databases)

2. Verified Undercarriage Fitment Dimensions

(Precision measurements from TM04I blueprint for Bobcat 9-bolt track frames)

3. Resolving Bobcat 331/425 Spigot Misalignment & Travel Power Loss

Experiencing bolt hole mismatch when installing replacement drives, or noticing track lag during heavy trench push? Bobcat 331 and 425 excavators utilize two distinct undercarriage patterns (9-bolt vs. 12-bolt). Installing the wrong unit forces bolt misalignment and severe radial runout against the drive sprocket. Over high operating hours, internal pressure bleed across the rotary cylinder barrel drops low-gear torque, preventing the 52.7:1 planetary gear set from delivering its 4200 N·m pushing capacity. Installing our precision-machined 6659564 / 6670667 final drive guarantees exact 204 mm spigot concentricity, stops fluid bypass, and reinstates full factory gradeability.

4. Frequently Asked Questions (Technical & Commercial)

For Machine Owners & Operators (C-End Insights)

Q: How do I verify my Bobcat 331 requires this 9-hole 204mm drive rather than the 12-hole unit? A: Count the mounting bolt holes securing the final drive to your track frame and measure the inner centering pilot hole of your drive sprocket. If your sprocket pilot measures 204 mm across with 9 mounting holes (φ12 mm), your machine requires this TM04I assembly. (If it has 12 holes, you need part 6677666-12H / 6692633).

Q: What is the mandatory startup lubrication procedure before running this drive? A: Pre-fill the hydraulic motor casing with fresh ISO VG 46 fluid through the upper casing drain plug. Separately, fill the planetary gearbox with SAE 80W-90 extreme-pressure gear lubricant up to the horizontal oil level check plug before starting the engine.

For Equipment Dealers & Repair Facilities (B-End Insights)

Q: How does 6659564 cross-reference with 6670667 and 6677666 in inventory? A: 6659564, 6670667, and 6677666 (9-hole configuration) are direct factory interchangeable assembly part numbers across the Bobcat 331, 334, 425, and 428 platforms, sharing identical 204 mm pilot spigots, 52.7:1 reduction gearing, and 40 L/min flow ratings.

Q: What are the exact freight logistics specifications for pallet and freight calculation? A: The crated assembly has a net weight of 52.0 kg (gross packed weight approx. 54.5 kg) and measures 34 × 34 × 44 cm (0.051 CBM). Each drive is sealed in vapor corrosion inhibitor (VCI) poly wrap and bolted securely inside an ISPM-15 certified fumigated export wooden crate.

5.Parts List