Transmission problems
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4wd Low
Joined: May 2022
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Transmission problems
I rebuilt my E4OD transmission several weeks ago after the forward clutch pack burned up and I lost forward gears. The truck drove fine for the first 300 miles on the rebuilt transmission. Today, I drove around 125 mostly highway miles, and the problems began when I turned it back on and started making my way home.
1. It shifted smoothly from 1-2 and then from 2-3, but on the 3-4 upshift, the torque converter would not lock and the shift would not complete. When this happened, the truck would not gain speed despite pressing down on the throttle, but it would gain RPMs the same way as if I were revving it in neutral; I avoided WOT and would not put the RPMs past 3,250 or so. At this point, I pressed the OD Off button on the shifter and limited the truck to the first three gears. If I turned the OD Off button back off, enabling the truck to engage fourth, it would upshift into fourth and would briefly lock up until I gave it some gas. At this point, the engine would increase RPMs without accelerating, and it would also have trouble downshifting back to third.
2. This mostly worked fine at highway speed, but new symptoms emerged after that: when I would slow down, it would not automatically downshift, but would stay in 3rd gear at a stop. The truck had terrible acceleration and didn't really get moving until about 20-25 mph, at which point it felt normal. After I observed this, when I had to stop, I would manually select 2nd gear to prevent this from happening and then shift to D when I got to about 20-25 mph.
3. Occasionally, it would stall out and die at a stop. If I put it back into neutral, it would start up again and would move in drive or manual 2nd.
4. I had to shut it down again at one point, and it sputtered and died the moment I put it into D gear. It started right up after putting it into park again.
5. R would not engage automatically, but would go into gear if I selected R and then gave the truck some gas. It didn't take much, but it would not do it on its own without this input.
I was able to get it back home driving on three gears, and then I started some diagnostics. KOEO and KOER tests both gave 111 codes, or system pass. When I had KOEO, I noticed the solenoid pack in the transmission was buzzing very loudly. This stopped after I disconnected the battery and replaced the PCM relay in the engine fuse box with a working relay I had on hand. I checked the transmission fluid and it was red and did not smell burnt, and it was in the crosshatched area of the dipstick so the level appears to be normal.
After reading through my FSM, there are so many potential diagnostic directions to go in that I'm at a loss where to begin. Many of these issues are related to dirty or sticky valves, so I can always drop the pan and inspect the valve bodies for play or damage. A line pressure test and a stall test would seem to be indicated for shift performance and torque converter clutch application. The buzzing solenoid pack makes me think there may be some electrical issues at play here, and because I did have to previously repair a couple wires in the solenoid harness when they became frayed that may be a good move too. Does anyone have any additional advice?
1. It shifted smoothly from 1-2 and then from 2-3, but on the 3-4 upshift, the torque converter would not lock and the shift would not complete. When this happened, the truck would not gain speed despite pressing down on the throttle, but it would gain RPMs the same way as if I were revving it in neutral; I avoided WOT and would not put the RPMs past 3,250 or so. At this point, I pressed the OD Off button on the shifter and limited the truck to the first three gears. If I turned the OD Off button back off, enabling the truck to engage fourth, it would upshift into fourth and would briefly lock up until I gave it some gas. At this point, the engine would increase RPMs without accelerating, and it would also have trouble downshifting back to third.
2. This mostly worked fine at highway speed, but new symptoms emerged after that: when I would slow down, it would not automatically downshift, but would stay in 3rd gear at a stop. The truck had terrible acceleration and didn't really get moving until about 20-25 mph, at which point it felt normal. After I observed this, when I had to stop, I would manually select 2nd gear to prevent this from happening and then shift to D when I got to about 20-25 mph.
3. Occasionally, it would stall out and die at a stop. If I put it back into neutral, it would start up again and would move in drive or manual 2nd.
4. I had to shut it down again at one point, and it sputtered and died the moment I put it into D gear. It started right up after putting it into park again.
5. R would not engage automatically, but would go into gear if I selected R and then gave the truck some gas. It didn't take much, but it would not do it on its own without this input.
I was able to get it back home driving on three gears, and then I started some diagnostics. KOEO and KOER tests both gave 111 codes, or system pass. When I had KOEO, I noticed the solenoid pack in the transmission was buzzing very loudly. This stopped after I disconnected the battery and replaced the PCM relay in the engine fuse box with a working relay I had on hand. I checked the transmission fluid and it was red and did not smell burnt, and it was in the crosshatched area of the dipstick so the level appears to be normal.
After reading through my FSM, there are so many potential diagnostic directions to go in that I'm at a loss where to begin. Many of these issues are related to dirty or sticky valves, so I can always drop the pan and inspect the valve bodies for play or damage. A line pressure test and a stall test would seem to be indicated for shift performance and torque converter clutch application. The buzzing solenoid pack makes me think there may be some electrical issues at play here, and because I did have to previously repair a couple wires in the solenoid harness when they became frayed that may be a good move too. Does anyone have any additional advice?
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