If a belt must be replaced, the driven unit or idler pulley must be loosened
and moved to its extreme loosest position, generally by moving it toward the
center of the motor. After removing the old belt, check the pulleys for dirt
or built-up material which could affect belt contact. Carefully install the
new belt, remembering that it is new and unused; it may appear to be just a
little too small to fit over the pulley flanges. Fit the belt over the largest
pulley (usually the crankshaft pulley at the bottom center of the motor) first,
then work on the smaller one(s). Gentle pressure in the direction of rotation
is helpful. Some belts run around a third, or idler pulley, which acts as an
additional pivot in the belt's path. It may be possible to loosen the idler
pulley as well as the main component, making your job much easier. Depending
on which belt(s) you are changing, it may be necessary to loosen or remove other
interfering belts to get at the one(s) you want.
When buying replacement belts, remember that the fit is critical according
to the length of the belt ("diameter"), the width of the belt, the depth of
the belt and the angle or profile of the V shape or the ribs. The belt shape
should match the shape of the pulley exactly; belts that are not an exact match
can cause noise, slippage and premature failure.
After the new belt is installed, draw tension on it by moving the driven unit
or idler pulley away from the motor and tighten its mounting bolts. This is
sometimes a three or four-handed job; you may find an assistant helpful. Make
sure that all the bolts you loosened are tightened and that any other loosened
belts also have the correct tension. A new belt can be expected to stretch a
bit after installation so, be prepared to readjust your new belt, if needed,
within the first two hundred miles of use.
CAUTION
On vehicles with an electric cooling fan, disable the power to the fan by disengaging
the fan motor wiring connector or removing the negative battery cable before
replacing or adjusting the drive belts. Otherwise, the fan may engage even though
the ignition is
OFF.
- Disconnect the negative battery cable.
- Loosen the accessory's slotted adjusting bracket bolt. If the hinge bolt
is excessively tight, it too will have to be loosened.
- Push the component toward the engine to provide enough slack in the belt
so that it will slide over one of the accessory drive pulleys. Remove the
drive belt from the accessory drive pulleys and from the vehicle.
To install:
- Position the new drive belt over the component pulleys. Make sure that it
is routed correctly.
- Adjust the tension of the belt, as described earlier in this section.
- Connect the negative battery cable.
- Disconnect the negative battery cable.
- Loosen the component's pivot and lockbolts.
- Inspect the tensioner assembly on the component; the tensioner adjusting
bolt may use a locknut or screw to prevent it from loosening over time. On
the type of adjuster with a threaded mounting brace, there may be two jam
nuts used on either side of the threaded coupling. If such locking fasteners
are found, loosen them.
- Turn the tensioner adjusting bolt or threaded coupling to relieve all tension
from the drive belt until the most possible slack is gained from the component.
- Slip the belt off of the accessory pulley, then remove it from the other
pulleys. Remove the belt from the vehicle.
To install:
- Route the new belt on the component pulleys. Make certain that it is routed
correctly; incorrect routing could cause a component to spin backward, possibly
damaging it.
- Once the belt is correctly positioned on all of the pulleys, adjust the
tension as described earlier in this section.
- Connect the negative battery cable.
- Disconnect the negative battery cable.
- Loosen the idler bracket pivot bolt and locking bolts.
- Move the idler pulley until the most amount of slack is gained.
- Remove the drive belt from the accessory pulley, then from the other applicable
pulleys.
To install:
- Position the new belt over the crankshaft pulley, the idler pulley and the
accessory pulley. Make certain that it is correctly routed, otherwise it could
cause the accessory to be rotated backwards. This could cause damage to the
accessory.
- Adjust the belt tension, as described earlier in this section.
- While holding the tension on the belt with the ratchet, tighten the locking
bolts, then the pivot bolt.
- Connect the negative battery cable.
- Disconnect the negative battery cable.
- Loosen the mounting/pivot bolt behind the idler pulley.
- Remove the drive belt from the accessory pulley, then from the other applicable
pulleys.
To install:
- Position the new belt over the crankshaft pulley, the idler pulley and the
accessory pulley. Make certain that it is correctly routed, otherwise it could
cause the accessory to be rotated backwards. This could cause damage to the
accessory.
- Swivel the idler pulley with a pair of pliers or a wrench on the bearing
mounting until the proper tension is achieved.
- While holding the idler pulley, at the proper tension, tighten the mounting/pivot
bolt.
- Connect the negative battery cable.
