Checking Belt Tensioner Spring Tension and Belt Wear

Belt drive systems equipped with an automatic (spring) belt tensioner cannot be adjusted or repaired. The automatic belt tensioner is designed to maintain proper belt tension over the life of the belt. If tensioner spring tension is not within specification, replace tensioner assembly.

Checking Belt Wear

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Belt Wear Inspection

A - Belt Tensioner

B - Poly-Vee Belt

The belt tensioner (A) is designed to operate within the limit of arm movement when correct belt length and geometry is used.

Visually inspect poly-vee belt (B) for excessive wear and cracks. See Replacing Fan and Alternator Belt in Section 45.

Checking Tensioner Spring Tension

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Marks on Tensioner

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Align Marks

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Align Torque Wrench With Pulley And Tensioner

A - Mark On Swing Arm

B - Mark On Tensioner Mounting Base

C - Torque Wrench

A belt tension gauge will not give an accurate measure of the belt tension when automatic spring tensioner is used. Measure tensioner spring tension using a torque wrench and procedure outlined below:

1. Release tension on belt using a breaker bar and socket on tension arm. Remove belt from pulleys.

2. Release tension on tension arm and remove breaker bar.

3. Put a mark (A) on swing arm of tensioner as shown.

4. Measure 21 mm (0.83 in.) from (A) and put a mark (B) on tensioner mounting base.

5. Install torque wrench (C) so that it is aligned with center of pulley and tensioner. Rotate the swing arm with the torque wrench until marks (A and B) are aligned.

6. Record torque wrench measurement and compare with specification below. Replace tensioner assembly as required.

   Item	Measurement	Specification
   Spring Tension	Torque	18-22 N˙m (13-16 lb-ft)

NOTE: Threads on belt tensioner roller cap screw are LEFT-HAND threads