Aircraft Alternator
Maintenance Manual
24-30-01
ES1031
Page: 6-6 Rev.
B: 20 Apr. 2022
© 2022 - Hartzell Engine Technologies - All rights reserved
Problem
Possible Cause
Corrective Action
Belt Slippage
Lack of tension
Overloaded drive
Worn pulley or V grooves
Oily drive conditions
Increase tension
Reduce load or check pulley size
Replace pulley
Clean drive, resolve oil leak
Belt turn over
Misaligned drive
Worn pulley or V grooves
Heavy Impulse loads
Excessive vibration
Broken cords cause by prying belt
over pulley
Wrong pulley or belt
Realign shafts and pulleys
Replace pulley
Check idler pulley (spring or not)
Check tension
Tension v-belt, if tension is good,
inspect belt condition or replace
Replace Belts, do not pry belt over
pulley
Check to see if belt rides high or if belt
bottoms out in groove
Rapid belt wear
Worn pulley grooves
Pulleys misaligned
Mismatched belts (Multi belts only)
Belt slippage
Pulley diameter too small
Overloaded Drive
Replace pulley
Align pulleys and brackets
Replace mismatched belts
Increase tension
Check P/N and/or replace pulley
Pulley size on components correct
Belt Separated
Foreign materials in drive belt
Belt slippage (over time)
Heavy start-up loads
Belts damaged during installation
Check that pulley is protected
Increase tension or replace belt
Reduce load before starting
Install new belts properly
Belt stretch
Excessive drive tension
Broken cords using multiple belts
Large Misalignment
Use proper tension
Replace belts with matched set
Realign brackets and pulleys
Belt squeal
Belt slippage
Insufficient arc of contact
Overloaded drive
Increase tension
Increase center distance
Pulley size on components correct
Belt chirp
Misaligned drive
Belt tilted in pulley groove
Belt riding on side of pulley groove
Align the pulleys and brackets
Correct angle of belt
Adjust bracket in or out of seat belt
Belt bottom cracks
High surrounding temperature
Pulley diameter too small
Belt slippage
Provide ventilation
Redesign drive
Increase tension
Overheated bearings
Continuous belt slippage
Excessive drive tension
Bearings not lubed or are damaged
Increase tension
Tension drive properly
Replace bearings
Table 6.3 - Alternator Maintenance (Belt)
