Detroit Diesel — Removal of Poly-V-Belts
Maintenance
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Do not use more than a 6 inch extension to reduce the danger of cracking the tensioner. Apply smooth pressure.
- Never turn the pulley idler arms clockwise.
Procedure
- Install a half-inch extension tool into the square hole on the grooved pulley idler arm.
- Turn the grooved pulley idler arm counterclockwise (max allowable torque 90-100 N·m).
- Insert an M10x80 bolt (or equivalent pin) into the bracket hole in the idler arm.
- Release the idler arm; it is now locked in a pre-tensioned position.
- Remove the fan drive belt.
- Install a half-inch extension into the square hole on the non-grooved pulley idler arm.
- Turn the non-grooved pulley idler arm counterclockwise (max allowable torque 90-100 N·m).
- Insert an M10x80 bolt (or equivalent pin) into the bracket hole in the non-grooved pulley idler arm.
- Release the idler arm; it is now locked in a pre-tensioned position.
- Remove the belt from the pulleys.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Idler arm maximum allowable torque: 90-100 N·m (66-73 lb·ft)
Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.