This morning I am pulling the trans out of my 2004 Freightliner 158" and disassembly begins. It's been a almost a month since the transmission failed on the fwy and now I am leaning more toward mechanical failure as opposed to electronic failure causing complete loss of drive. When I discovered ATF had launched a full scale attack on my TCM with a little help from the wire harness that goes to the leaking NAG1 electrical connector at the Transmission. Both connectors at the TCM were dripping with ATF but no fluid made it inside the module. After cleanup of both TCM connectors and the electric terminals on the TCM I was hoping that that would be enough to put me back on the road.
No such luck.
After a brief conversation with Dr. A, I followed his suggestion in focusing on locating a DAD or DRB III or Snap-on Modus to see what codes were stored inside the modules but I have not been successful in my search but I found a tool that seems to communicate with my TCM and reads,erases,and displays live data from all 3 shift solenoid circuits as well as torque converter lock up solenoid and both pressure regulating solenoids and speed sensors. Initially this tool pulled a Y3/6Y2 fault code in the tcm referring to the shift pressure control solenoid valve being faulty. After reading several different articles on the history of the 722.6, I replaced the conductor plate on the valve body because I learned there are issues with this part and it is more than likely is what is causing the fault code to appear. After replacing the plate, I tested each solenoid with an ohmmeter at the TCM connector and found the values on all solenoid circuits within the acceptable range according to the ATSG 722.6 Transmission Service Manual. I trust ATSG as I have used their guides before, first in 2002 when I rebuilt my Chevy Turbo 400 out of my '70 Corvette and then in 2005 for my Jatco trans out of my '89 Isuzu NPR. Both rebuilds were many years ago but the ATSG guides for each of them were easy to follow and both transmissions worked perfectly when completed.
I reinstalled the valve body, refilled with Shell ATF 134, cleared codes on the TCM and ECU and after several key cycles and engine run time no codes have returned but still have complete loss of drive.
The Scantool is a LAUNCH CREADER PROFESSIONAL CRP 123 and shows the "Targeted gear" referring to which gear the selector is in and "Actual gear" which i"s what the computer is telling the scantool which gear the trans is actually in. When in park both show "P", when in neutral both show "N", When in reverse the targeted gear shows "R" the actual gear shows "N", when in drive targeted gear shows "D" actual gear shows "N".
I probably could use a little nudging before I tear into this for a complete disassembly as maybe it isn't a mechanical failure and I am overlooking a electrical problem that is causing this "Stuck in the driveway" mode.
I do have some tools from the previous Transmission builds but I am lacking at least one tool to do this trans which is a press for the K 1,2,3 and B 1,2,3 drums for frictions replacement, which shouldn't be too difficult to make.
Here goes.....
No such luck.
After a brief conversation with Dr. A, I followed his suggestion in focusing on locating a DAD or DRB III or Snap-on Modus to see what codes were stored inside the modules but I have not been successful in my search but I found a tool that seems to communicate with my TCM and reads,erases,and displays live data from all 3 shift solenoid circuits as well as torque converter lock up solenoid and both pressure regulating solenoids and speed sensors. Initially this tool pulled a Y3/6Y2 fault code in the tcm referring to the shift pressure control solenoid valve being faulty. After reading several different articles on the history of the 722.6, I replaced the conductor plate on the valve body because I learned there are issues with this part and it is more than likely is what is causing the fault code to appear. After replacing the plate, I tested each solenoid with an ohmmeter at the TCM connector and found the values on all solenoid circuits within the acceptable range according to the ATSG 722.6 Transmission Service Manual. I trust ATSG as I have used their guides before, first in 2002 when I rebuilt my Chevy Turbo 400 out of my '70 Corvette and then in 2005 for my Jatco trans out of my '89 Isuzu NPR. Both rebuilds were many years ago but the ATSG guides for each of them were easy to follow and both transmissions worked perfectly when completed.
I reinstalled the valve body, refilled with Shell ATF 134, cleared codes on the TCM and ECU and after several key cycles and engine run time no codes have returned but still have complete loss of drive.
The Scantool is a LAUNCH CREADER PROFESSIONAL CRP 123 and shows the "Targeted gear" referring to which gear the selector is in and "Actual gear" which i"s what the computer is telling the scantool which gear the trans is actually in. When in park both show "P", when in neutral both show "N", When in reverse the targeted gear shows "R" the actual gear shows "N", when in drive targeted gear shows "D" actual gear shows "N".
I probably could use a little nudging before I tear into this for a complete disassembly as maybe it isn't a mechanical failure and I am overlooking a electrical problem that is causing this "Stuck in the driveway" mode.
I do have some tools from the previous Transmission builds but I am lacking at least one tool to do this trans which is a press for the K 1,2,3 and B 1,2,3 drums for frictions replacement, which shouldn't be too difficult to make.
Here goes.....