CMP Service Issues - Things to Watch Out For

[Phil Waterman]

Hi All

Well to put this problem in perspective, in an unscientific study, 2 out of 3 CMPs may have this problem, after finding the loose Jack-Shaft Bolts on my C60S checked both C60L and HUP. Results of this was both large trucks had loose or not tight drive shaft flange bolts. The HUP didn't but then again it is under a 1000 miles since overhaul.

That other people have had this problem does raise as suggested that these bolts deserve regular checking.

Replacing the bolts and nuts with modern self-locking nuts is a definite option but I have had problems find bolts with the right length un-threaded shanks so there are no threads in either side of the flange to provide a tight fit for the bolts. I have looked several times for drive shaft bolts through truck sources without luck and have had to resort to using grade 8 bolts with 20 threads. But to get these in the right shank length the bolts are too long and have to be cut to length.

The photos below of TASK NO.9 from the Drivers Handbook - It has an couple of interesting points, 1st "These nuts MUST be tightened with a torgue wrench." yet the required tool list at the beginning of the task doesn't list a torque wrench and it hard to get a torque wrench square on to get a true reading because of the universal joint on the drive shaft.
2nd point makes sense in the Military "Report if Loose"

I now consider my loose bolts Duly Reported.

Cheers Phil