Hello again!
Different truck, and a different transmission problem. We actually bought it just a month or so ago, so it's been a learning experience. The windows often roll up of their own accord. I can't tell if that's just fancy truck quirks or if this particular truck just has an attitude problem.
Truck Specs:
2003 Sierra 3500 SLT
6.6L V8 Diesel LB7
Automatic
4x4 w/ Auto Switch (push buttons)
Allison 1000 (1st Gen, 6 solenoids, 1 signal tube)
VIN - 1GTJK33173F213128
What's Happening:
I'll start the truck while it's in park (as one does) and it takes a rather extreme amount of force to pull the stick down into reverse, after which point I will have to fiddle for some time with the stick before it will be convinced to enter any gear other than reverse. It'll even try to pull backwards against the lock of the parking gear if I let off the brake. I can eventually (usually) persuade it to enter nuetral or drive. Once in drive it has decreased power and it feels like it has a lot of friction, but it doesn't feel as if there is any extra engine (or transmission) braking force going on when I let off the gas. When driving even short distances it will increase in heat quite fast, climbing all the way up to the red lines at 300 (which I try my best to pull over and avoid). When over 200, it is near impossible to get it back into drive after pulling over and going into park.
What codes it has:
P0700 - Transaxle Control System Malfunction (non-specific code of high severity)
P0872 - Pressure Switch Solenoid 'E' Low or Stuck Closed
P0847 - Transmission Fluid Pressure Sensor Issue
What have I done?:
What do I think?:
I've done some research and it looks like there might be a few things I could also do. It's at 340k miles and after laying in it a few times now I'm pretty darn sure it's still on original trans fluid, because it is heckin' grunky black void gruel. That might be an exaggeration. It's actually more of a translucent dark brown with black slime balls settling to the bottom. But somebody told me that changing the fluid when trying to fix anything else in the trans is a bad idea. i've also heard that anyone who says that is full of crap. I personally think the tranny might well enjoy some fresh juices after taking a look inside the valve body, but I'm personally quite ignorant, so I haven't changed it yet out of abundance of caution.
I've also seen that transmission temp sensor/valve thingy malfunctions can cause shifting problems in some Sierras so I tried to find the transmission cooler (it's the small one farthest forward from the engine, right?) and felt it's lines while the trans temp gauge was over 200 degrees and decided that the line was not actively scalding me and instead was pleasantly room temp. Not sure if I just found the wrong cooler though.
So. What do y'all's think I should try next?
Different truck, and a different transmission problem. We actually bought it just a month or so ago, so it's been a learning experience. The windows often roll up of their own accord. I can't tell if that's just fancy truck quirks or if this particular truck just has an attitude problem.
Truck Specs:
2003 Sierra 3500 SLT
6.6L V8 Diesel LB7
Automatic
4x4 w/ Auto Switch (push buttons)
Allison 1000 (1st Gen, 6 solenoids, 1 signal tube)
VIN - 1GTJK33173F213128
What's Happening:
I'll start the truck while it's in park (as one does) and it takes a rather extreme amount of force to pull the stick down into reverse, after which point I will have to fiddle for some time with the stick before it will be convinced to enter any gear other than reverse. It'll even try to pull backwards against the lock of the parking gear if I let off the brake. I can eventually (usually) persuade it to enter nuetral or drive. Once in drive it has decreased power and it feels like it has a lot of friction, but it doesn't feel as if there is any extra engine (or transmission) braking force going on when I let off the gas. When driving even short distances it will increase in heat quite fast, climbing all the way up to the red lines at 300 (which I try my best to pull over and avoid). When over 200, it is near impossible to get it back into drive after pulling over and going into park.
What codes it has:
P0700 - Transaxle Control System Malfunction (non-specific code of high severity)
P0872 - Pressure Switch Solenoid 'E' Low or Stuck Closed
P0847 - Transmission Fluid Pressure Sensor Issue
What have I done?:
- I've added a little dex6 trans fluid 'cause it was low on the hot hashes. (This truck also has cold hashes, curiously)
- I have replaced the E solenoid (middle one next to the TCC solenoid).
- After that didn't work I replaced all of the solenoids at the same time.
- I have removed the entire valve body, cracked it open, and cleaned it thoroughly and made doubly sure that all of the valves slide in and out nice and smoothly. Which was a great idea because it was actually pretty interesting to see how everything worked and also it absolutely grunky, chunky, lunky everywhere in there. No metallics though (yay!)
- I prayed. It didn't work. Maybe there's a delayed reaction?
What do I think?:
I've done some research and it looks like there might be a few things I could also do. It's at 340k miles and after laying in it a few times now I'm pretty darn sure it's still on original trans fluid, because it is heckin' grunky black void gruel. That might be an exaggeration. It's actually more of a translucent dark brown with black slime balls settling to the bottom. But somebody told me that changing the fluid when trying to fix anything else in the trans is a bad idea. i've also heard that anyone who says that is full of crap. I personally think the tranny might well enjoy some fresh juices after taking a look inside the valve body, but I'm personally quite ignorant, so I haven't changed it yet out of abundance of caution.
I've also seen that transmission temp sensor/valve thingy malfunctions can cause shifting problems in some Sierras so I tried to find the transmission cooler (it's the small one farthest forward from the engine, right?) and felt it's lines while the trans temp gauge was over 200 degrees and decided that the line was not actively scalding me and instead was pleasantly room temp. Not sure if I just found the wrong cooler though.
So. What do y'all's think I should try next?
