Transmission (4L80E) First and Second Gear Only
Hello,
This is my first Diesel and my first Chevy Truck.
My transmission only has First and Second Gear Only (no reverse, third or OD). I bought it this way, please don't ask why - I get enough grief from my wife.;)
I've done a lot of searching on the web and have found conflicting info on the root cause and what the fix would be.
I don't now very much about transmissions but my gut tells me that it is more likely an electronic or hydraulic problem rather than a catostrophic mechanical failure. But maybe this is just wishful thinking and am in denial about the possibility of replacing a sun gear, sun ring, sun shell, sprag or some other part requiring a rebuild (or close to it).
I bought the ATSG (Automatic Transmission Service Group) manual "THM 4L80-E" for this transmission ($25 download PDF).
In the troubleshooting charts they call out this specific condition "FIRST AND SECOND GEAR ONLY"
INSPECT COMPONENT FOR CAUSE
Solenoid B (311)Stuck Off
Loose Connector
No Voltage to solenoid
Solenoid o-ring failure
no PCM signal to solenoid
2-3 Shift Valve Stuck
Quad Driver Module Failed
Possible Codes:
68 Overdrive Ratio
81 QDM & Solenoid B Fault
85 Undefined Ratio
87 Solenoid B Stuck Off
I was getting a code 87 and quickly (maybe hastily) went and replaced the 2-3 Shift Solenoid. This did not fix it.
While I was in there I should have checked the voltages to check for loose connecter, no voltage to solenoid and/or no PCM signal to solenoid.
I also should have checked the 2-3 Shift Valve
Does anybody know if I should see voltages if the truck is not running, but the ignition is in the "on" position and I put it in reverse or 3rd?
Any experiences that you can share would be appreciated. I'll post back with my results.
Thanks!
Paul
P.S. I bought a B&M Automatic Transimssion Drain Plug Kit #80250 to make future transmission fluid changes less of a hassle - in my opinion balancing a tray of hot tranny oil over your chest or face should be avoided ;)
P.S.S. I may have posted this in the wrong forum.... should it go in the "2500HD/3500 HD Trucks & Drivetrain" forum?