Hi , im new to the site and to be honest i joined in a moment of frustration because i wanted help from all you guys here and see if anyone has any input or has had a similar problem and maybe can help me solve this problem!

** I WILL TRY TO PROVIDE AS MUCH INFO AS POSSIBLE SORRY IF ITS LONG**

i have a single cab '04 gmc sierra , 5.3L , 2wd , auto 4l60e , eaton true posi , 3.73 rear end , mild cam (not sure on specs) , cai , flowmaster true duals

when i first got the truck it had already been cammed but everything else was stock completly and ran really strong and had plenty of power and torque , i could sit at a light at idle and just punch the throttle and it would just roast the one tire and catch no traction , i could do a brake stand and again would light up the tire with no problems at all , i could get off the line decently like would be expected from a stock 5.3l 2wd ,

one night out having some redlight fun/racing , nothing crazy other than just your normal 0-60 pulls from a light , i was manually shifting my transmission (something i had normally always done) when all o a sudden when going from second to third gear i skipped third gear and put it into what felt like reverse ( i know stupid thing to do i felt like **** ) .. the truck automaticlly AND QUICKLY starts to come to an abrubt stop all while making this grinding clinking noise that appeared to be coming rom the tranny, so im sitting there in mid street and it wont go into gear i shut it off and turn it back on after a couple minutes and it goes into drive only after i slowly go into reverse and let it sit for a second or two until it made a clinking noise then it let me shift into drive... i drove it off fine no noises but i quickly noticed i had no second gear! i drove it like this for the next two days fine until i got it to the transmission shop,

** WHERE MY PROBLEM STARTS**

i went online and bought the 4l60e SS monster in a box COMPLETE transmission rebuild kit from Monster Transmissions , and also bought an SS3200 high stall converter from YANK , along with a Heavy duty transmission cooler , had all this put into my transmission , also had my whole rear end rebuilt and get an eaton full time posi and 3.73 gears to go with it, so i go pick up my truck finally , well i give it 500 miles of carefully driving it and babying it to allow proper break in and when i go to try and brake stall the truck i notice it wont stall past 1500rpm!! no matter what i do! and when i let off the brake as if to launch the truck is SUPPER SLUGGISH and has no power! , one of those days it rains and i take my truck outside and try to burn some rubber just to see if it has the power to do so and IT WONT EVEN MOVE A SINGLE TIRE!! again i try to launch it , and wont rev up past 1500 , and when i let off it wont even so much as chirp the tires in complete WET PAVEMENT! .. i punch it from idle at complete stop and NOTHING, but once i get up over 35mph the truck seems to perform great it has plenty of power and when i punch it going 37-39mph it kicks into OD and takes off QUICK! even uo at 65mph i punch it and the truck takes off like no other! .....it is just under 35mph and from a dead stop that it has NO POWER AT ALL!! if i take off from a light at full throttle or even semi throttle it takes forever to get up to about 35mph , if i was to stop halfway up a little hill and try to take off it probably wouldnt make it up the hill from a dead stop! a stock geo metro will LITERALLY RIP me off the line up until 35mph


PLEASE SOMEONE HELP ME!! ANY INPUT IF GREATLY APPRECIATED !

 

Take a video of the speedometer when you take off from a stop and go WOT.

 

Almost sounds like your transmission isn't leaving stops in 1st gear.

Do you have a Check Engine light on? Did you have the PCM retuned for the converter/trans combo? If not, the PCM may be commanding the trans to 3rd gear only (limp mode) and max line pressure.

 

- I will try to take a video and post it as soon as i get a chance

- i do have a check engine light but this just came on recently and its for my cats because i just recently cut them off , i havnt had the PCM retuned yet , yes! it does feel exactly like if it was taking off in 3rd gear , but that line pressure does ring a small bell because believe it or not ive already had the converter pulled 2 times and rebuilt because the fins were being bent over each time , this last time i had it completly rebuilt bottom up billet everything plus stator , etc.

 

" I yanked it, and got off slower " - YANK

 

I have the same thing with my tt3000.

 

Need to get a scan tool on it and see if it's commanding the shift's or if its stuck in 3rd as mentioned.

Can you manually put it in first and go through each gear???

 

I know with mine I'm battling a po121 code if that helps. Which is my tps sensor.

 

I need to go drive this with ya...! I can throw a Tech II on it and see what we can figure out!

 

Did you pull the gear shifter toward you to shift up into the next gear?
big nono since all you have to do is push it straight up. it wont go into reverse unless your pulling it past the reverse lockout tab.


It does sound like its not goin into first gear now tho. have you tried to manually drop it into first?
but being a 3200 it should go past 1500 especially with it being in a bind.

hit up 89ls1foxer and see what the tech ii says.