Alliance Belt Tensioner - Detroit DD13 / DD15 / DD16 Serpentine - Gates 38667 Detroit A4722000170 GT38667

Put constant, correct tension back on the serpentine drive with this Alliance Automatic Belt Tensioner distributed by FleetPro Parts & Tires. It is the Freightliner aftermarket accessory drive belt tensioner for Detroit DD13 and DD15 engines, equivalent to the Gates FleetRunner heavy-duty assembly, and it applies constant spring force to the serpentine belt so the alternator, water pump and fan clutch stay driven without slip. Replace it when you hear belt squeal or chirp, see belt fluttering or rapid edge wear, or find a seized, wobbling or grease-leaking pulley, all signs the spring or the bearing has worn out. We stock these heavily right here in our Hanover Park, Illinois warehouse to ensure lightning-fast shipping for fleets, diesel repair shops, and owner-operators nationwide.

Constant Spring Force: The Alliance DD-Series Tensioner Advantage

This is a full automatic spring-loaded belt tensioner assembly, not a pulley kit. The machined steel pulley carries a V-ribbed contact surface and measures 75 mm OD over a 30 mm bearing bore, riding on a double-row sealed bearing sized for the loads a heavy accessory drive puts through a tensioner arm. An internal asymmetric damping mechanism controls how fast the arm can move, which is what keeps the belt from oscillating when the engine changes load.

At roughly 11 lb this is a substantial piece of hardware, and it mounts on the front accessory drive to control tension on the main serpentine belt that turns the alternator, water pump and cooling fan. At FleetPro Parts & Tires, we know a DD-series belt job is one you want to do once. This tensioner is a direct replacement for highly searched industry numbers including Gates 38667, Detroit A4722000170, A4722000570, A4722001670, Kit Masters 638667 and Alliance ABPN20638667.

Vehicle Fitment & Compatibility

This heavy-duty belt tensioner is intended for the following commercial applications:

• Engine: Detroit Diesel DD13, DD15 and DD16
• Freightliner: Cascadia P3 2008-2017 and P4 2018-2024
• Also Fits: Western Star and other Daimler trucks running these engines
• Position: Front accessory drive, controlling the main serpentine belt
• Drives: Alternator, water pump and cooling fan

Direct Replacement & Cross-Reference Numbers:

This Alliance belt tensioner serves as a direct replacement for the following part numbers:

• Gates Interchange: 38667
• Detroit Interchange: A4722000170, A4722000570, A4722001670
• Kit Masters Interchange: 638667
• Alliance Interchange: ABPN20638667
• FleetPro Part #: GT38667

Technical Specifications

• Component Type: Automatic Spring-Loaded Belt Tensioner Assembly
• Pulley: Machined steel, V-ribbed contact surface
• Pulley OD: 75 mm
• Bearing Bore ID: 30 mm
• Bearing: Double-row, sealed
• Damping: Internal asymmetric damping mechanism
• Approx. Weight: 11 lb
• Condition: New
• Warranty: 1-Year FleetPro Warranty
• Brand: Freightliner (Distributed by FleetPro Parts & Tires)