You know the line "who cares, its a rental"????... Keep that in mind..
When units train to NTC/FT Irwin, there is an equipment pool that is for use by the visiting unit so they dont have to spend the $ and time rail loading homestation equipment. They "borrow" it for a few weeks then return it.. As you can imagine, the borrowing unit doesnt do as good of a job maintaining it as they would if it was they own stuff.. Add in the occasional abuse, and multiply it by a few dozen times a year... See where this is going??? Thats why if you buy anything from GL out in Barstow/Ft Irwin that has a 4 digit "bumper number" be VERY wary.. They are from the equipment loaner pools... I've never been to JRTC/Ft Polk, so I cant say for sure, but Im sure someone else here might of been and can comment on it..
Short short story on one of my experiences.. One of my guys had a M35A2 we borrowed. At the end of the exercise, you need to turn in the truck atleast 3/4 full of fuel.. There was no fuel to be had anywhere(those that have been there will understand that)... All this kid had to do was find 20-30 gal of fuel, turn in his truck, and he could fly home THAT day.. He asks me what to do, I told him to find some fuel somewhere.. He starts kicking a rock in frustration that is on the desert floor.. He kicks one and it flys off into the desert.. He suddenly stops, picks up a fist sized rock, and says "Sir, I think I found the fuel I needed".. He runs off, comes back a hour later, truck is all turned in. Im sure the next unit that drew that truck wondered why it seemingly burned up fuel faster than any other truck there and had to be refueled more often than the rest.......
I'd bet a few dollars that your truck was part of the Infantry Battalion PREPO fleet there...