am on my way back to michigan after dropping three horse carriages off. just pulling an empty trailer now (2200 lbs) . with any minor uphill grade this truck shifts out of overdrive.
have talked to folks on the roqad with the same truck who are pulling 5th wheel travel trailers who say they are going up the same hills and never shift out of overdrive. what is wrong with this thing?
also when it shifts down, if i have much pulling to do to finish the grade the temp gage goes up and the truck acts like i am shutting the truck off and on (engine continues to run)

 

First off, you must check lift pump, change fuel filter, put an good flowing air filter on it, Check trouble codes in computer also. If engine is putting out the power it should. Put shift kit......vavle body upgrade or something in it and then get ride of the junk stock tork convertor. If you want Power, box or chip in with ez edge or something. You must also remeber in is not a gas and don't run the same, but should hold the hills better than a gas and do better on fuel.

 

Check for boost leaks.

 

mine did the exact same thing, it was a boost leak...the lower boot coming off the intercooler was loose