for some reason my truck gets really hot after about an hour of driving. it is not leaking any water and is always full of coolant. the hottest its gotten is one mark from the "h" does anybody have any reason why it is doing this

 

Probably needs a thermostat. The original has a small by-pass that allows some to get through so you don't cook it, but it'll still run pretty warm.

 

i sec the thermostat(cummins)!!!!

when the temp stated to climb,do you here the fan pulling air (fan roar?) if not this could allso be part of the problem.

 

no not usually

 

Look inside the radiator for scale and gunk, too. The older a vehicle gets, the more clogged the rad gets. No radiator will last forever, how long just depends on how well it is maintained.

 

sound like the fan clutch is the problem.......unfornunly chry has discontinued there fan clutch for the 89-91.0 so you will have to go aftermarket.
If you have the option,buy the heavy duty or the one for ac!