I'll leave the rest of it for the experts, but just a quick note on this part:
Also out of curiosity, the GVW on the door states 19,500 lbs and research shows me that dry the girl should weight around 9500 lbs, so technically is this truck then a 5 ton? I was under the assumption that the C60 family was all 2.5 ton trucks, but this GVW shows me at double that, on a single dual axle as well.
It's common in the truck world to confuse "GVW" with "2-ton" versus "1/2-ton," etc). First off,
go read our Tech Tip on this subject. But in a nut shell, the truck's GVW as listed on the data plate is the important one to know for loading the bed of the truck. Whether the truck is called a "half-Ton" or a "2-ton" or a "5-ton" is an archaic holdover from the early days and *only* refers to the weight/load rating of the *front* axle.
This becomes important when you start thinking about a repower. If you go with a heavy engine (like a V-8 or a diesel of some sort) and a heavier transmission, or anything that puts more weight on the front axle (including the rest of the front of the truck) than, say, "2 tons," you will want to replace your front axle, as well, or you may be dangerously overloading your front axle.
About the 2-speed -- Smooth 2-speed axle shifting comes with practice. And don't use the clutch! Do it in this order -- 1. Pull (or push) the knob in 2. let off on the accelerator and count to two/wait for the clunk, and 3. return to the accelerator. (Don't get steps one and two reversed or you will get a bad noise
) That's how it always worked for me on my '65 big truck. Upshifting is easier than down shifting. And keep in mind that shifting the 2-speed is much harder when the truck is empty/light. Try leaving the axle in low range until you get to the top and then shift the axle into high -- treat it like an overdrive. When it comes time to down shift, leave it in high until you get to the bottom (when you are stopped at the light, push in the knob and wait for the clunk). The purpose of the two-speed is to help the "little" engines start big loads and to keep speed up when shifting on hills. So when the truck is light/empty, you might not need to use low range at all. Of course, your application may be different from mine -- I had a GMC 4400 with the 305 v-6 (the torque monster). The 292 may be similar, though, so try it and see. When it comes time to drive the truck with an actual load on it, then you will want to use the 2-speed on every shift and you will find it behaves much better.
Now get rid of those RH-5's as soon as you can.
Do *not* load that truck with much weight until you have safe wheels, and new, properly inflated tires! (and good brakes and steering, too!) We want you around for a long time now that you've found us.
Welcome aboard! Check out the rest of our Tech Tips, too.
John
