CASE WHEEL LOADERS:
• Case 621/621B/621C 6BT 5.9L Diesel (1995-2006)
KOMATSU EXCAVATORS:
• Komatsu PC210-6D/PC210-7/PC210-8K 6BT/QSB 5.9/6.7L Diesel (1996-2010)
KOMATSU WHEEL LOADERS:
• Komatsu WA200-5/WA200-6/WA250-5/WA250-6 4BT/6BT 3.9/5.9L Diesel (2002-2016)
• Komatsu WA320-5/WA320-6 6BT 5.9L Diesel (2002-2016)
CUMMINS INDUSTRIAL ENGINES:
• Cummins 4BT 3.9/4BTA 3.9/6BT 5.9/6BTA 5.9 4BT/6BT 3.9/5.9L Diesel (1984-2007)
IMPORTANT:
This tensioner has a SMOOTH (flat) pulley — designed for flat/non-grooved serpentine belts on Cummins 4BT 3.9L and 6BT 5.9L mechanical engines. If your engine uses a GROOVED (V-ribbed) belt, you need 3976831 instead. Ordering the wrong pulley type is the #1 mistake — a smooth pulley on a ribbed belt causes rapid belt wear and premature failure.
Supersedes 3937553, 3917485. Alternates: 3922900, 3934818, 5333477. Case IH cross-references: 87326910, 47683084. Fits mechanical B-series engines in Case wheel loaders (621 series), Komatsu excavators (PC210) and wheel loaders (WA200-WA320), and other off-highway equipment with 4BT/6BT power.
Failure symptoms: belt squeal, alternator undercharging, cooling system overheating from water pump slippage. A worn tensioner spring allows excessive belt deflection even if the belt itself is new. Inspect belt condition and routing before installing — verify the belt rides on the smooth side of pulleys throughout the drive path.
⚠️ SMOOTH pulley only — if your belt has ribs/grooves, order 3976831 instead.
Total Reviews (0)
Write the First Review!