Frame Fastener Torque Check

Frame brackets and components secured with Huckbolt® fasteners do not require a torque check, however, they should be inspected for damage. Frame brackets and components secured with conventional bolts and nuts are to be checked at initial maintenance (IM). See Fig. for pre-EPA07 engine mounts. Check the torque of frame fasteners to offset the effects of "bedding in" (or seating). When possible, always check the torque of the nut, not the bolt head. This will give a true torque reading by eliminating bolt body friction. When checking the torque of frame fasteners, inspect the frame for cracks and other damage. Set a click-type torque wrench to the maximum torque of the fastener you are checking. Apply pressure until the torque wrench clicks. Do not loosen the bolt to check the torque. See in the vehicle workshop manual for torque specifications.

Capscrew, 3/4– x 4.5 Inch, Grade 8

Washer, 3/4 Inch

Engine Leg

Capscrew, 1/2–13 x 1.5 Inch, Grade 8

Washer, 1/2 Inch

Upper Isolator

Rear Engine Mount

Nut, 5/16–18

Capscrew, 5/8–11 x 2.5 Inch, Grade 8

Washer, 5/8 Inch

Lower Isolator

Nut, 3/4–10

Nut, 5/8–11

Fig. 1, Rear Engine Mount Assembly (pre-EPA07 engines)

Inspect and check the fasteners at the following locations:

• axle stops

• deck plates

• engine trunnion supports

• equalizer brackets

• exhaust brackets

• fifth wheel legs

• fifth wheel mountings

• frame crossmembers and gussets

• front frame brackets

• front suspension spring brackets

• fuel tank brackets

• radius rods

• rear engine supports

• rear suspension spring brackets

• shock absorbers

• all other suspension fasteners

• all other axle fasteners

• all other frame fasteners

Any component that shows signs of cracking, or other damage, must be repaired or replaced. See the applicable group in the Century Class Trucks Workshop Manual for repair or replacement information.