Transmission/torque converter?

2004 CHEVROLET SILVERADO
20,000 MILES • 6.0L • V10 • 2WD • AUTOMATIC
Avatar
6.0ANGEL
  • MEMBER
  • 3 POSTS
i was driving normally and everthing was working fine and i let my truck sit for about 2 hours and after i tried to drive i had completely lost 1st and 2nd gear. there was no loud bang or clunking noise and my oil looks perfectly fine, its a 4l80e trans with a 3600 converter and now i only had 3rd gear and overdrive. if you have any ideas on what could be the issue please let me know.
Apr 21, 2026 at 11:06 PM
Advertisement
Avatar
6.0ANGEL
  • MEMBER
  • 3 POSTS
my engine is a lq9 v8 not a v10 sorry
Apr 21, 2026 at 11:09 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
I would run the codes first to see which ones are stored so we don't go off in the wrong direction to fix it. Please go over this video.

https://www.youtube.com/watch?v=LBCpCWEFnTg&t

A bad Shift Solenoid A/B, wiring issue, poor connector contact, or blown trans fuse can do this. So lets check the transmission fuses (6) as well which I have listed in the images below. This video should help as well.

https://www.youtube.com/watch?v=G-xNK79Wa-w

Check out the images (below). Please let us know what happens.

Image (Click to enlarge)
Attached Media
Apr 23, 2026 at 8:14 AM
Advertisement
Avatar
6.0ANGEL
  • MEMBER
  • 3 POSTS
i put a scan tool on and code P0756 Shift Solenoid B Performance or Stuck Off popped up. i then checked all the fuses and they where good. the transmission fluid looks perfectly fine. would i just have to change those solenoids now?
Apr 23, 2026 at 2:11 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
Yep, you called it, the code P0756 - Shift Solenoid B Performance/Stuck Off, this usually points to a problem with the 2-3 shift solenoid circuit or hydraulic control inside the transmission, not always the solenoid itself. But let try the solenoid because the other option usual involves rebuilding the transmission. Here is the location of the solenoid so you can sap it out. Check out the images (below). Please let us know what happens.
Image (Click to enlarge)
Attached Media
Apr 24, 2026 at 7:38 AM