Still hauling sandbags and supplies during the flood. Day 7 today. Went through water up to the hubs today...but new silicone boots, new axle seals etc. should be ok. I will check once the mess is over. A few interesting things...oil burn of about 2 quarts in the first two days. No noticeable oil burn since. I checked and smelled the oil. No diesel contamination that I can detect. Maybe really loading the engine helps seat the rings better?
I looked up the cargo carrying capacity on this site. I know what TM and data plates say. 10,000 lbs on the highway. As someone explainted very well, it is important to understand what the military meant by these terms. "Off-road" is any terrain a soldier might flog the truck through, thinking it could maybe make it. "Highway" just means you follow a dozer through the same terrain. The military did not envision today's road system in their definitions.
Form a component standpoint, the truck is about an 18 ton / 40,000 lbs truck. The limitations are the tires and today's traffic reality on the road. It is no longer being accepted that a heavy truck is slow to go and takes loooong to stop.
I have been loading 9 tons (about 18,000 lbs) regularly now and agree with the sentiments on this site. I checked the spring packs (do not appear to be at the limit) and tires (modern radials) and I remain well within their rated capacity . The brakes, however, are at their limit at that weight.
Not an issue for me because the majority of my loads is local. less then 5km and in low range only. Only some are about 30km and high range; I limit my loaded speed to 40 mph. I am not flogging her, keeping an eye on the EGT and boost and keenly aware of the fording depth for the axles/diffs.
I have a new found respect for the capacity of my truck, the reliabiltiy of hauling heavy day after day after f***g flooding day and the fact that she is happy with fresh diesel, a bit of oil and a dollop of grease.
And, man, does that LDS ever bite into it! I have the 0.69 Overdrive and it will do grades in 5th high, loaded as described above. I keep boost at around 10 (she will happily blow past 15 if I am not watching) and the EGT (pre turbo) at 1000. Respect.