I own two Ch635 Macks 2004 they have the 330-350 hp engines,T310 transmission,3.87 diff. gear,and 22.5 tires. I don't have enough power to pull 10th gear with 80000lb load of chips. I have had these trucks to Mack dealer several times to check programming for power,every time to be told the engine was at peak performance.We have eliminated the egr coolers and had checked by dealer with the same answer. I had R model Macks with 237hp that would run better than these.What can I do? Change the diff. or the trans. or change engine hp somehow,without breaking the bank.
