Paccar Kenworth T170 Hybrid 2011, Builder'S Manual

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Section 7
Frame Modifications
7-5
12/11
WELDING
The 9 .875” and 10 .62” rails along with the 9 .875” insert are heat treated; therefore, it is not weldable .
The 9.875 (9-7/8) inch rail, 10.62 (10-5/8) inch rail and the 9.88 (9-7/8) insert for the 10.62
inch rail are heat treated; therefore are not weldable. Welding can affect frame rail
strength leading to a failure resulting in serious injury and /or an accident. Rail failures
resulting from such modifications are not warrantable.
To determine if the frame rails are heat treated:
1 .
Check for heat treat caution labels on the frame rails. See figure 7-5.
FIGURE 7-5. Heat Treated Frame Rail Warning
Kenworth DOES NOT recommend frame welding. The high heat of welding nullifies the special heat treatment of the
rails, greatly reducing the tensile strength of the frame rail. If a frame member becomes cracked from overloading, fatigue,
surface damage or a collision, the only permanent repair is to replace the damaged frame member with a new part .
The following information is provided (for temporary emergency repair). Prior to welding a cracked frame rail, the area
should be beveled (V’d out) to allow for a better weld. To prevent spreading of the crack, a 7 to 9 mm (1/4 in. to 3/8 in.) dia.
hole should be drilled at the end of the crack . Widen the crack along its full length by using two hack saw blades together .
When welding steel frames use the shielded arc method . When welding aluminum frames use either the tungsten inert
gas (TIG) or consumable electrode method . Be sure to obtain full weld penetration along the entire length of the crack .
Precautions
Before welding, disconnect the negative terminal battery cable. Failure to comply may
result in equipment damage.
Before welding, disconnect the alternator terminals. Failure to do so may result in
damage to the voltage regulator and/or alternator.
To prevent damage to electrical equipment, disconnect battery cables before arc-welding
on a truck, and be sure that the welding ground lead is connected to the frame. Bearings
and other parts will be damaged if current must pass through them in order to complete
the circuit.
CAUTION:
CAUTION:
CAUTION: