Usage:
Challenger 75 (4CJ),
Challenger 75C (4KK),
Challenger 85C (9TK) Tractors
Description of Change: The mounting brackets on the air-to-air aftercooler assembly have been made stronger. See Illustration 1. The new mounting brackets (1) are thicker [4.8 mm (.19 in) versus 3 mm (.12 in)] than the former mounting bracket. The new mounting brackets are "L" shaped with reinforcing straps (2), while the former brackets were "U" shaped. These changes will help prevent the brackets from cracking. The new mounting brackets have also provide easier access to the aftercooler mounting bolts.
Illustration 1. (Current 7E8470 Aftercooler Assembly Viewed From The Rear). New thicker, "L" shaped mounting brackets (1). Reinforcing straps (2).
Adaptable To: The part number of the improved 7E8470 Aftercooler Assembly with the stronger mounting brackets has not changed. The improved aftercooler assembly is in effect with Challenger 75C (4KK500) and Challenger 85C (9TK1) Tractors. The improved aftercooler assembly is adaptable to all earlier Challenger 75 and Challenger 75C Tractors.
The 7E8470 Aftercooler Assembly on earlier Challenger 75 and Challenger 75C Tractors can be modified to help prevent the mounting brackets from cracking. Use the procedure that follows:
Illustration 2. (Earlier 7E8470 Aftercooler Assembly Viewed From The Rear). (A) Location to weld on fabricated reinforcing plate. (B) Location of cut-outs on bottom mounting bracket.
1. Fabricate a reinforcing plate from 1.5 mm (.060 in) thick SAE AA 6061-P6 or SAE AA 3003-H14 Aluminum. The plate should be a rectangle that is 71 mm (2.8 in) by 35 mm (1.4 in).
2. Use the mounting holes in the original bracket as a guide to make the mounting holes in the reinforcing plate.
3. Weld the fabricated reinforcing plate to the face of the lower right side mounting bracket.
4. There are cut-outs in the bottom mounting bracket where the bracket meets the bottom of the aftercooler assembly. Fill these cut-outs with weld.