I have an 01 also with a 6 spped. I tow a high profile fifth wheel. I usually am in 6th running about 62 MPH with 1800 RPM, and about 950 to 1050 degrees on the EGT's. I drop to fifth if climbing a hill, but in 6th most of the time.

 

I tow in 5th gear all the time.

NV5600, 3.73 gears, stock tires, 10k fifth wheel.

60mph/100kph, approx 2400 RPM.
A little high but the EGT's are fine and I never have to downshift & exhaust brake holds it back fine in 5th gear down hills.

As was mentioned, 6th gear (overdrive) is the weakest gear in the trans.


...Joe

 

I tow in 6th all the time with my G56.

No problems so far.

GCVW about 20,000# - 22,000#