Transmission Shifting Problem
 

Hey guys I’m having an issue with my transmission. First off it was rebuilt by a local guy about a year ago and has ran fine up until about a month ago. I have a 2003 4DR 4WD Blazer. The problem I am having is when I am accelerating my tranny shifts fine from first to second, from second to 3rd it revs really high at ¼ throttle before it shifts, and that’s if it shifts. Sometimes it will rev high and stay at 3K RPM or a bit above until I completely release the gas pedal. The same thing happens from 3rd to 4th. When I’m cruising on the highway it will shift but if I barley hit the gas (and I mean barely) it will down shift to 3rd (as if I fully depressed the gas pedal) when I KNOW it should be in 4th. Not thinking right, I recently unplugged the battery and it erased my code that I had for a CEL (check Engine Light) but I know I had a CEL for a EVAP problem I was having and didn’t get a chance to reset it after that problem was fixed. So m not sure if there was a CEL for the tranny or not. But it still has not popped up with one. Also when I reset the ECU from the battery pull it seemed like it actually made a difference from my 2nd to 3rd shifting point. Still does it but not as often. The 3rd to 4th is still the same although? Fluid is good, not sure if this could be a solenoid problem or not?

Thanks for the help

Any one???

Sit down & start searching. There's lots in here about trans shift issues so I'm sure you can find lots to read about in order to figure out what's going or not going on.
Sounds like a pressure issue &/or solenoids, possibly wiring.
It IS a 4L60E (E for electronic)

Downshifting too early, my guess is the problem is in the valve body of the trans. Take it back to the guy who rebuilt it.