I have an 01 1500 Sport and I bought it a year ago with 120k and knew nothing about the truck. Drove fine and still does, I pull about 6k lbs at least a few times a month and always has plenty of power, I honestly think the trans was replaced at one point, well today I started noticing the following:

If im driving in a 30mph speed zone (ex: neighborhood) it will rev at like 2-2300k and not want to shift until I get to about 35mph and then it upshifts into 3rd, it never used to upshift that late and then it will want to downshift for a quick second if I go down to 33mph. Also, sometimes when I start approaching a red light and im doing about 10mph, it will do somewhat of a harder downshift. However, if I was to pull a trailer, PLENTY OF POWER, NO ISSUES. If I was to beat on it or just drive it normal, NO PROBLEM, but when im driving though neighborhoods and slow speed zones, thats where I have the issues. Thoughts?

 

possible governor pressure sensor, or solenoid. when was the last time tranny fluid/filter was changed?

 

I dont know, I dont know any history of the truck before I bought it, ive had it for a year and put about 15k, I will check the fluid, im always scared of changing fluid but if its a newer trans then I should be fine, if the fluid is black then I shouldnt change it, correct? I always her horror stories of transmissions going bad after a new fluid was installed

 

Don't flush it. ATF +4 also doesn't do the color/smell change thing well enough to use it as an indicator. I am more concerned about what you find in the pan, and if the governor solenoid is getting clogged with crap. (which is typical.)

 

How do I check the governor solenoid or do I have to remove the pan?

 

Yep pan has to come off.

 

BTW, the best way to describe my problem is driving with OD OFF, it feels like that. When OD is ON, it will up-shift pretty much right away but now it feels like OD is OFF since it takes a little longer for it to up-shift into 3rd

 

gov pressure sensor is prone to malfunction from dirty fluid and normal trans debris.
read through MonteC's transmission threads for more info.
when all else is good, he recommends transmission fluid change, and/or cleaning or replacing gov pressure and/or solenoid.

if all else is good, you may just need one or two fluid changes and it might even take care of itself. if not, its easy to replace, including replacing with the GM conversion. see Monte's threads.