Usage:
CHALLENGER 75D (5AR285-410),
CHALLENGER 85D (4GR403-590) AGRICULTURAL TRACTORS
Problem:
There have been reports that some of the clamps on the engine air inlet lines may have been excessively tightened on the above tractors. Excessive tightening of these clamps may cause a clamp failure. The illustration identifies the clamps that may have been excessively tightened.
Solution:
The correct tightening torque for the 135-6259, 135-6260, and 135-6261 Uniform Load Clamps (identified in the illustration) is 5.6 to 6.8 N·m (50 to 60 lb in). At that torque the spring under the nut will be fully compressed.
Use a torque wrench with an inch pound scale and a 7/16 inch deep socket to check for the correct torque on these clamps. Slowly turn the torque wrench in the direction to tighten the clamp nut. If the tightening torque is slightly low, continue to tighten the nut to the correct value. If the tightening torque is very low and the clamp appears to twist, inspect the clamp for damage and replace if necessary. If the tightening torque is too high and the clamp is not damaged, fully loosen the clamp and then tighten the clamp to the correct torque.
Caterpillar requests that dealers send reports of the results of torque checks on these clamp nuts via E-mail to COURTST @ MOSSSYA for a period of one month from the date on this TIB, then stop.
Air lines (A). Uniform Load Clamps to be checked (B). Turbocharger (C).
RIGHT SIDE VIEW OF ENGINE AIR INLET LINES
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