2003, one ton, Cummins 24 Valve. 122K. Is my Fathers, who passed in 2017. My mother refuses to sell it, so it sits, as she doesn't know how to drive it. I come up, once a month, and take it out for a bit. It gets about a 1000 Miles per year on it. So far, maintenance wise, it always gets work done in Clinton, Mo. Dodge dealer, where he bought it. In the last two years it has gotten oil changed, coolant changed, tranny fluid changed. I tried to get them to change the 20 year old brake fluid but they looked at me like I was on drugs. Anyhoo, the issue I have, well, more of an oddity, is when I get up there, I disconnect the battery tender, start the truck (it is garaged) and shift to reverse, it takes a good 30 seconds to one minute to finally start moving. Doesn't matter how long its allowed to warm before shifting. It slowly engages, then shifts normally as though nothing is wrong. Has no other shift issues, and fluid level is on the mark. Anyone know of a reason why it does this? Truck runs great otherwise. Just an oddity as to why it does this.