hello
I've got an 03' sierra with the orig. 4l60e and 130k on it within the last month it has started to down shift slowly. Example is when im goin about 25mph and floor it the eng revs up slowly and the truck speeds up but it takes about 2sec. for it to down shift to first and then really go. it isnt sliping the motor is reving at the same speed as the speedo it just takes 2sec to actualy make the down shift. Anybody ever heard of this before, if so how do i fix or repair?
Any help would be great THANKS. Bob.

 

What does your fluid look like?

 

Fluid is red, smells fine not burnt. I havent noticed any slipping at all.

 

Stock tune? Maybe it has to do with Torque Management? They say the average life of the stock 4L60E is around 80k - 130k.......but mine lasted until 214k before slipping.

Are you sure it's not slipping and then grabbing? Mine is doing that on the down-shift....the sprag is messed up.

 

Its not slipping, I have had a truck that the tranny was slipping and this is nothing like that its just taking a long time to shift down, other shifts are fine my only tune is the hypertech handheld that is set to stock just changed the speed limiter. My only mods are a muffler and putting in the 5.3 thats it. I have had the trany flushed and filter changed every 60k, so twice, both times they said no problems. It did improve a little when i took out my sand bags (480lbs.) but not the way it used to be.

 

sometimes from a 20 roll or so i can floor it and it wont even down shift, its like its in 2nd gear and slowly climing.

 

Thats alot like whats happining to me but it does down shift just slow. So I guess there is nothin I can do I just have too live with it.

 

depends... i'd be curious to see what type of (actual) line pressure you're seeing when you romp on the gas at that speed. There's a number of variables that affect shifting. Pressure is one of the reasons people switch to the vac mod... maximum pressure as opposed to relying on electronic control.

 

how would i check that? i will have to search for that vacume mod. ive never heard of it.

 

Odds are you don't have one. 46-MOD is what it's called. Contact Vince or Chuck @ Finish Line Trans (PT.net sponsor ---->), and they can answer any question you have (from a professional standpoint) regarding what could be the best route for troubleshooting. Plus they stock parts you may need to help that trans live longer.