7500 in a new 4l60 and it wont shift. 411 swap. Need some help

[Motorsports-X]

• Truck is a 96 k1500 5.7 with a 411 swap and a 2002 express van tune. I dont know if any segment swaps were done
• Trans was just replaced with a 1999 tahoe trans so I could get the 2 peice bell housing
• Trans was built by a experienced and reputable trans shop that specializes in performance builds
• Trans is full of sonnax parts, including their HD valve body.
• pinout for swap was using lextech's document
• Truck is a "put together" from oklahoma. pretty sure it has a v6 dash. engine bay stickers say 305 came factory.
• truck has headers and misfires but misfire was set to min ect 266 to prevent that from being an issue with shifting.
  

So I picked the truck up last week. Company that built the trans didnt install it for me, someone else did. Drove it home 15 miles and didnt notice any problems. Seemed like i had all 4 gears. Sat for week and took it out today to go hunting and it will barely move from a start. feels like its trying to start in high gear, or like it might be trying to fight itself. in reverse it feels absolutely fine, so it doesnt feel like a power issue.

Commanding gear changes doesnt seem to have any effect only in 3 to 4. and if I turn of the demand for 4th it shifts immediately back to third.
pulling the lever from d4 to d3 or d2 doesnt do anything, nothing shifts either up of down when moving the stick. d1 is locked out. litterally cant pull the shift lever that far. Possily wrong bracket on trans? D4 and d3 do line up with the correct positions.

PCM shows "current gear" changing, and the turbine speeed is changing but that must be calculated and not actual because nothing is shifting.

I do have a P0756 code shift solenoid B stuck off code.

new tun 11 24.hpt
drive and on jacks.hpl

[TransGo Robert]

• Truck is a 96 k1500 5.7 with a 411 swap and a 2002 express van tune. I dont know if any segment swaps were done
• Trans was just replaced with a 1999 tahoe trans so I could get the 2 peice bell housing
• Trans was built by a experienced and reputable trans shop that specializes in performance builds
• Trans is full of sonnax parts, including their HD valve body.
• pinout for swap was using lextech's document
• Truck is a "put together" from oklahoma. pretty sure it has a v6 dash. engine bay stickers say 305 came factory.
• truck has headers and misfires but misfire was set to min ect 266 to prevent that from being an issue with shifting.
  

So I picked the truck up last week. Company that built the trans didnt install it for me, someone else did. Drove it home 15 miles and didnt notice any problems. Seemed like i had all 4 gears. Sat for week and took it out today to go hunting and it will barely move from a start. feels like its trying to start in high gear, or like it might be trying to fight itself. in reverse it feels absolutely fine, so it doesnt feel like a power issue.

Commanding gear changes doesnt seem to have any effect only in 3 to 4. and if I turn of the demand for 4th it shifts immediately back to third.
pulling the lever from d4 to d3 or d2 doesnt do anything, nothing shifts either up of down when moving the stick. d1 is locked out. litterally cant pull the shift lever that far. Possily wrong bracket on trans? D4 and d3 do line up with the correct positions.

PCM shows "current gear" changing, and the turbine speeed is changing but that must be calculated and not actual because nothing is shifting.

I do have a P0756 code shift solenoid B stuck off code.

new tun 11 24.hpt
drive and on jacks.hpl

Your shift solenoid B is stuck open, the solenoid feed orifice in the plate is restricted, or the computer is not actually grounding the control wire as it thinks it is. It is shifting 4-3-3-4 when the computer commands 1-2-3-4. Very unlikely to be a command issue but before going in the pan I would monitor the voltage on the control wire to make sure that it does have zero volts when it is commanding 1st and 2nd, and then full battery voltage when the computer is commanding 3rd and 4th.

[Estep40511]

I totally read that subject line wrong. I thought he was doing 7500rpm with a 4L60 LOL. I was going to say, well thats a first!

[blindsquirrel]

I totally read that subject line wrong. I thought he was doing 7500rpm with a 4L60 LOL. I was going to say, well thats a first!

Oh they will do 7500 at the 1-2, it's just a question of how many times it'll do that.