Detroit Diesel — Time Blower Rotors
Adjustments
From a Detroit Diesel service manual — check it applies to your exact model before use.
Procedure
- Time the rotors to have a minimum clearance of .014 in between the trailing edge of the right-hand helix rotor and the leading edge of the left-hand helix rotor (CC clearance) measured from both inlet
- Check the C clearance (leading edge of right-hand helix rotor to trailing edge of left-hand helix rotor) for a minimum of .024 in. Take rotor-to-rotor measurements 1 in from each end and at the center
- Add shims back of the proper gear to produce the desired result. Placing a .003 in shim in back of a rotor gear will revolve the rotor .001 in.
- Install the required thickness of shims back of the proper gear and next to the bearing inner race, and reinstall both gears. Recheck clearances.
- Determine minimum clearances at points A and B between end plates and rotor ends (12 measurements). Check clearance between each rotor lobe and the blower housing at inlet and outlet sides (12 measure
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- CC clearance minimum .0140 in
- C clearance minimum .0240 in
- Backlash limits .0040 in
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.