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Automatic Belt Tensioner Assembly - Mack MP8 / Volvo D13 - Mack 21714847 Gates 38633 819.38633
Automatic Belt Tensioner Assembly - Mack MP8 / Volvo D13 - Mack 21714847 Gates 38633 819.38633
Automann

Automatic Belt Tensioner Assembly - Mack MP8 / Volvo D13 - Mack 21714847 Gates 38633 819.38633

Only 2 left
SKU: 819.38633
$116.83
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Fitment

Fits these trucks

Mack CHU Pinnacle 09-16, CXU Pinnacle 12-17, GU Granite 09-15Volvo VAH 15-17, VHD 07-17, VN 15-17Mack MP8 and Volvo D13 (12.8L) enginesEngine accessory drive - belt tensioner position
Always confirm your year, make & model before ordering.
Part numbers

OEM & interchange numbers

4 cross-refs
Mack 21714847 Gates 38633 Contitech 49586 Dayco 89935DAY
Direct 1-to-1 replacement for every number above. Tap any number to copy.
Overview

Keep the belt tight and quiet with this Automatic Belt Tensioner Assembly distributed by FleetPro Parts & Tires. It is the spring-loaded pulley assembly that holds correct tension on the accessory belt of Mack MP8 and Volvo D13 (12.8L) engines. When the spring inside a tensioner goes weak or the pulley bearing turns rough, the belt starts to flutter and squeal, wears out long before its time, and eventually lets go on the road. 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.

Quiet, Consistent Belt Tension: The Automann Tensioner Advantage

A tensioner is a wear item, not a lifetime part. The internal spring loses force with every heat cycle and every million belt revolutions, and the pulley bearing collects the grit and salt spray that any front-of-engine component lives in. This complete assembly replaces the spring, the arm and the pulley together, so you are not putting a fresh belt against the tired half of a worn pair. At 4.88 lbs, it is a straightforward bolt-on that does not require pulling the front of the engine apart.

Manufactured by Automann to Fleet Standard specification and covered by the 1-Year FleetPro Warranty, this tensioner is the practical answer when the belt is chirping on a cold morning or you can rock the pulley by hand. At FleetPro Parts & Tires, we know a belt job that leaves the old tensioner on the engine is a belt job you get to do twice. It is a direct replacement for highly searched industry numbers including Mack 21714847, Gates 38633, Contitech 49586 and Dayco 89935DAY.

Vehicle Fitment & Compatibility

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

  • Mack: CHU Pinnacle 09-16, CXU Pinnacle 12-17, GU Granite 09-15 with MP8
  • Volvo: VAH 15-17, VHD 07-17, VN 15-17
  • Engine: Mack MP8 and Volvo D13 (12.8L)
  • Component Group: Engine Accessory Drive / Belts & Tensioners

Direct Replacement & Cross-Reference Numbers:

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

  • Mack Interchange: 21714847
  • Gates Interchange: 38633
  • Contitech Interchange: 49586
  • Dayco Interchange: 89935DAY
  • Automann Distributor #: 819.38633

Technical Specifications

  • Component Type: Automatic Belt Tensioner / Pulley Assembly
  • Function: Maintains correct belt tension
  • Engine: Mack MP8; Volvo D13 (12.8L)
  • Weight: 4.88 lbs
  • Condition: New
  • Warranty: 1-Year FleetPro Warranty
  • Product Level: Fleet Standard Aftermarket
  • Brand: Automann (Distributed by FleetPro Parts & Tires)
Key features
  • Complete Assembly, Not a Half Repair: The spring, arm and pulley are replaced together, so a fresh belt is not fighting a tired tensioner.
  • Ends Flutter and Squeal: Replaces tensioners with weak springs or rough bearings, the exact cause of belt flutter, squeal and premature belt wear.
  • Correct for MP8 and D13: Built for the Mack MP8 and Volvo D13 (12.8L) application rather than adapted from a generic tensioner.
  • Wide Mack and Volvo Coverage: Covers Mack CHU Pinnacle 09-16, CXU Pinnacle 12-17 and GU Granite 09-15 plus Volvo VAH 15-17, VHD 07-17 and VN 15-17.
  • Backed by FleetPro: New Automann hardware built to Fleet Standard specification and covered by the 1-Year FleetPro Warranty.
Specifications
Component Type
Automatic Belt Tensioner / Pulley Assembly
Function
Maintains correct belt tension
Engine
Mack MP8; Volvo D13 (12.8L)
Weight
4.88 lbs
Package Dims
9 x 4.75 x 4 in
Condition
New
Warranty
1-Year FleetPro Warranty
UPC
889626467660
Product Level
Fleet Standard Aftermarket
Questions
Will this fit my truck?
This part fits Mack CHU Pinnacle 09-16, CXU Pinnacle 12-17, GU Granite 09-15, Volvo VAH 15-17, VHD 07-17, VN 15-17, Mack MP8 and Volvo D13 (12.8L) engines, Engine accessory drive - belt tensioner position. Always confirm your year, make and model before ordering.
What part numbers does it replace?
Yes. It is a direct replacement that interchanges with Mack 21714847, Gates 38633, Contitech 49586, Dayco 89935DAY.
How fast does it ship?
In-stock orders placed before 12 PM Central on business days ship the same day from our Hanover Park, IL warehouse, and typically arrive in 2 to 5 business days anywhere in the USA.
What's your return policy?
Unused items in original packaging can be returned within 30 days, backed by our 30-day money-back guarantee. If we ship the wrong part, we cover the return label and send the correct one.