Series-Specific Belt Tensioner Kit – Fits Bobcat 873 S300 T300

Cross-Reference Validated — Belt tensioner kit variants for Bobcat skid steer and track loaders verified against superseded numbers and serial prefixes before shipment.

Technical Specifications

Application Suitability

Why the Same Base Number Arrives in Multiple Variants Across Bobcat Generations

Matching a Belt Tensioner Kit for Bobcat skid steer loaders requires serial-level verification, not just a part number lookup.

Bobcat part numbers supersede across machine generations, and the same base tensioner assembly often ships with different arm geometries, pulley bearing configurations, or spring torque specifications depending on the engine family installed. A tensioner that physically bolts onto an 873 may not maintain correct belt alignment on an S250 due to a revised accessory drive layout. Ordering by number alone without cross-reference validation risks receiving a unit with the wrong mounting pattern or insufficient spring preload for the target application. [NEED_CITE: Bobcat service bulletin superseded part number tracking procedures]

Serial Range Coverage and Variant Identification

This Belt Tensioner Kit spans the Bobcat lineup from the legacy 653 through the current S300 and T300 platforms. However, within that broad compatibility range, the arm pivot alignment, pulley runout tolerance, and mounting hole pattern vary by engine serial prefix. Providing the full machine serial number — or at minimum a six-character prefix — allows the technical team to confirm which variant within the 6662997, 6702474, or 6725212 cross-reference group applies to your specific build. A Belt Tensioner Kit for Bobcat skid steer applications on the S220, for instance, may differ in arm length from the kit suited to a T190 track loader.

Interface Verification Points Before Committing to Fitment

The critical dimensional checks for this tensioner assembly include the mounting flange bolt pattern spacing, pulley outer diameter and groove profile, and the arm pivot bore diameter. On Bobcat machines where the engine compartment has seen prior service, previous rebuilds may have introduced non-standard fastener sizes or modified bracket positions. Confirming these interface dimensions against your existing unit eliminates the risk of on-site modification or forced fitment. The CNC-machined 6061-T6 aluminum arm holds a ±0.05 mm dimensional tolerance, ensuring the pivot axis remains aligned with the accessory drive plane when the correct variant is selected. [NEED_CITE: belt drive alignment tolerance standards for compact equipment engines]

Specification Details That Determine On-Machine Performance

The 608ZZ deep-groove ball bearing inside the idler pulley uses double-lip nitrile seals rated IP54, preventing dust and moisture ingress that commonly causes pulley seizure on demolition and quarry sites. The torsion spring, wound from ASTM A228 music wire hardened to Rockwell C47–50, maintains consistent belt tension across the engine's operating temperature range without relaxation. O-rings manufactured to SAE J200 Class B specification resist compression set at sustained temperatures up to 120°C, preserving the seal between the tensioner arm and its pivot housing over extended service intervals. These material selections address the specific failure modes observed in Belt Tensioner Kit applications across the Bobcat loader range.

The Hidden Cost of Installing a Close-But-Wrong Variant

A tensioner arm with the correct bolt pattern but incorrect spring preload will maintain apparent belt tension at idle while allowing slip under load, accelerating belt wear and generating heat that degrades adjacent seals. A pulley with the wrong groove profile may track the belt slightly off-center, causing edge wear that leads to premature belt failure — often misdiagnosed as a belt quality problem rather than a tensioner mismatch. On-site forced fitment of a near-correct variant introduces stress concentrations in the aluminum arm that can lead to fatigue cracking within weeks of installation. [NEED_CITE: belt drive misalignment failure analysis in mobile equipment]

Why Sourcing Through This Channel Reduces Fitment Risk

Selected part lines are produced in-house while the remainder is sourced from qualified ISO-certified manufacturing partners, both carrying identical QC and warranty terms on this Belt Tensioner Kit. The eight-category product range means associated belt drive components — belts, idlers, and fasteners — ship under one account with consolidated documentation. Minimum order starts at one piece, supporting single-unit emergency replacements without forced bulk purchasing. Part identification is confirmed from a part number, machine model, photograph, or nameplate image. Cross-reference verification covers superseded and alternate numbers across the 6662997, 6702474, and 6725212 group. A sample unit is available for physical fitment confirmation before any bulk commitment.

Documentation & Verification

• Commercial invoice lists each tensioner variant by confirmed machine serial match
• Cross-reference sheet maps superseded numbers with reference only notation
• Dimensional check record covers flange pattern, pulley diameter, and pivot bore
• Six-month warranty terms provided in writing with each shipment
• Packing photographs taken before crate closure for condition documentation
• HS code classification support included for customs clearance

Fitment Check Before Installation

• Compare mounting flange bolt hole spacing against the removed tensioner before bolting on
• Verify pulley groove profile matches the belt cross-section installed on the machine
• Confirm arm pivot bore slides onto the mounting stud without lateral play
• Check torsion spring anchor points align with the engine bracket retaining features
• Rotate the idler pulley by hand to detect bearing roughness before belt installation
• If any dimension deviates, halt installation and submit photographs for re-verification

Request a Fitment Confirmation

Provide your Bobcat machine model and full serial number, or a clear photograph of the existing tensioner and its nameplate if the part number is partially legible. The technical team will return a cross-reference confirmation identifying which variant within this Belt Tensioner Kit range matches your specific equipment build.

Frequently Asked Questions

Q: How do I confirm this tensioner kit fits my specific Bobcat model and serial number? A: Submit your machine model and full serial number, or at minimum a six-character serial prefix. The technical team cross-references your build against the 6662997, 6702474, and 6725212 group to identify the correct arm geometry, spring preload, and pulley variant. Fitment confirmation is returned before any order is processed.

Q: My old part number does not appear in current catalogs — is there a superseded replacement? A: Bobcat frequently supersedes tensioner part numbers across machine generations. The cross-reference verification covers discontinued and alternate numbers within the same functional group. Provide the worn or partially legible number from your existing unit, and the team will identify the current valid replacement that fits your specific serial range.

Q: Why does the same base number have different arm or pulley variants across model series? A: Different Bobcat engine families and accessory drive layouts require distinct arm lengths, spring torque values, and pulley bearing types even when the base assembly concept is shared. Variant assignment is tied to the engine serial prefix, which is why machine serial verification is necessary before confirming which Belt Tensioner Kit ships.

Q: I only have the machine model, no readable part number — can you still identify the right kit? A: Yes. The machine model combined with the serial number is sufficient for identification. If the nameplate is worn or painted over, a photograph of the existing tensioner mounting area and arm profile allows visual comparison against known variants. This approach has resolved identification for machines where all stamped numbers were illegible.

Q: Can I get a sample to test fitment before placing a larger order? A: A single sample unit ships for physical fitment verification on your machine before any fleet-level or bulk commitment. This eliminates the risk of receiving a full order that requires on-site modification. Sample lead time and dispatch details are confirmed upon request with your machine serial information.