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The DS-3978021 belt tensioner replaces old part number DS-3936197.
This high quality aftermarket replacement part is guaranteed to meet OEM specifications and is shipped with a 12-month warranty.
WATER INLET CONNECTION - 4BT / 6BT / ISB / QSB
Genuine Cummins Part
$90.39
$1,579.08
BELT TENSIONER BRACKET - ISB
$176.59
ALTERNATOR SUPPORT - 4B3.10 / 6B5.10 / ISB3.9 / ISB4.5 / QSB3.9 / QSB4.5
$132.12
