Transmission shifting hard

[WillyT]

2005 2500 HD w/ auto trans. When cold, trans shifts great through all the gears (but "unlocks" after just a few miles when running 2500 to 3000 rpm). Anyway, when it begins to warm up, it always shifts hard between 3rd and 4th with a noticble jolt rather than a smooth crisp shift. I fear that damage is being done to trans. Any thoughts as to why this is shifting this way and how to remedy?

[dewfpo]

Welcome WillyT,

 

How many miles on it? and how long has it been since you've changed the atf? checked the fluid level?

 

DEWFPO

[WillyT]

Welcome WillyT,

 

How many miles on it? and how long has it been since you've changed the atf? checked the fluid level?

 

DEWFPO

 

 

Low miles (16000) but is rebuilt title, so warranty no good. Rebuilder had only put about 400 miles on prior to my purchase, and was only "around town" so did not notice any problems. I did not notice when I test drove, probably b/c only went a few miles. I have to drive over 10 miles usually before this problem presents itself. Fluid level is fine and fluid looks good.