Before adjusting belt tension, check the tension several times. Use an average of the readings.
Belt tension checks must be made at midpoint between pulleys at the longest belt span. Refer to Belt Tension
Chart (Table 3-2).
In multi-belt drives, the belt tension readings taken on the same span may vary considerably between belts.
When this occurs, average readings to establish applied tension, except in the application of the power
steering pump, where the values stated are for each belt.
Table 3-2. Belt Tension Chart
New Belt Installation
95-100 lb (423-444 N)
80 lb (356N)
New truck upon delivery
After 10 hours (or 300 miles)
After 50 hours (or 1,500 miles) 80-85 lb (356-378 N)
After intervals of 200 hours
(or 600 miles)
50 lb (222N)
Minimum Permissible Tension
60 lb (267N)
50 lb (222N)
3-10 FRAME AND TOW HOOKS
Because Navistar chassis are manufactured with frame rails of either mild carbon steel, HSLA steel, heat-treated
steel or aluminum alloy, each must be handle in a specific manner to assure maximum service life. Before attempting
frame repair or modification, consult the service manual.
Front and rear tow hooks should be inspected for damage or a loose mounting.
This is of great importance, particularly on vehicles where the tow hooks are used frequently.
3-11 FUEL AND LUBRICANT ADDITIVES
Refer to Fuel and Lubricant Additives segment in Chapter 4 of this manual.
3-12 FUEL SYSTEM 3-12.1
Frequently check throttle linkage for proper operation.