With my 36,000 lb, single clutch disk, 819, I start out in 2nd. low, then 3rd low, 4th low, 5th low, 4th hi, 5th hi. The reasons I do the shifting this way is
1 -- a 36,000 lb truck even without a load is VERY hard on a single disk clutch, most heavy trucks have twin disk clutches.
2 --...