This article describes the Cummins DD13/15/16 engine drive belt replacement
NOTICE
Never rotate the automatic belt tensioners clock
wise. To do so may damage them, and require
replacement of the entire assembly. To prevent
damage to the belt tensioners, always rotate
them counterclockwise. Never use more force
than 66 to 73 lbf (90 to 100 N), or you could dam
age the tensioner.
IMPORTANT: When releasing the automatic belt
tensioners and removing the drive belts, always
work on the front tensioner and belt (fan drive)
first, then the rear tensioner and belt (alternator,
A/C compressor, and water pump). When you
unlock the belt tensioners, reverse the proce
dure; unlock the rear belt tensioner first, then
front one.
5. Insert a 1/2-inch breaker bar, or 1/2-inch ratchet
into the square hole in the idler arm of the front
belt tensioner (grooved pulley), then smoothly
rotate it downward (counterclockwise) until you
feel resistance. See Fig. 3.
Fig. 3, Releasing the Front Tensioner
6. Insert a 10 mm diameter x 80 mm long bolt into the round hole on the idler arm of the tensioneras shown in Fig. 4, then push it all the way in.After the bolt is pushed all the way in, the tensioner will be locked in the released position. Remove the socket wrench from the square hole.
7. Insert a 1/2-inch breaker bar, or 1/2-inch ratchet,into the square hole in the idler arm of the rear
Fig. 4, Releasing the Rear Tensioner (smooth pulley)
belt tensioner (smooth pulley), then smoothly ro tate it downward (counterclockwise) until you feel resistance. See Fig. 4.
8. Insert a second 10 mm diameter x 80 mm longbolt into the round hole on the idler arm of the rear tensioner as shown in Fig. 5, then push it all the way in. After the bolt is pushed all the way in, the tensioner will be locked in the released posi tion. Remove the wrench from the square hole.
9. Replace the drive belts, making sure the new belts are correctly installed on all the pulleys.
10. Using the 1/2-inch breaker bar, or 1/2-inch ratchet, rotate the idler arm on the rear (smooth
pulley) tensioner downward (counterclockwise), until you can remove the locking bolt. Smoothly release the idler arm all the way up, being care ful not to jerk it.
11. In the same manner as the previous step, re move the locking bolt from the front tensioner.
12. Do a final check to make sure both drive belts are configured correctly, and correctly installed on all the pulleys.
13. Close the hood, connect the batteries, then remove the chocks.
