4R70W no OD after rebuild
#1
4R70W no OD after rebuild
I managed to replace all the damaged gears and other hard parts in my 2002 E150 transmission and did a full rebuild on it after it self-destructed. I did not change the solenoid valves but I now suspect that I should have. It shifts smoothly until you get to the time that overdrive should engage but it doesn't. If you drive a bit at a steady speed around 50 mph the OD light on the shifter will start to flash. Once you turn it off and restart it, the flashing stops. I did not drive it again to see if it repeats, but I can tell that Overdrive is not engaging. Pressing the OD off button does not seem to change the engine RPM.
Is it most likely the solenoid valve or could I have not put it back together right? Any help is appreciated.
Is it most likely the solenoid valve or could I have not put it back together right? Any help is appreciated.
#2
You should get the code that is stored in the computer, this can shed some light on where the problem may be.
When you install the overdrive band servo you can miss the band, it should be held in place for the servo to engage it. Does it shift into neutral at the 3-4 shift?
I don't think this is a solenoid problem at this time.
When you install the overdrive band servo you can miss the band, it should be held in place for the servo to engage it. Does it shift into neutral at the 3-4 shift?
I don't think this is a solenoid problem at this time.
#3
I will have to take it someplace to read the code after it turns on. My code reader shows no codes and the OD light stops flashing when restarted after turning off the engine.
I did triple check the OD band and actuator rod when I installed it, so I am fairly certain that this part of the assembly is correct. When driving the van, it drives exactly like it would with the "OD Off" switch engaged. As a matter of fact, I turned off the OD and drove it several miles and it did not generate a fault. It only starts flashing the OD light when driving over a mile or so with the OD switch in the normal mode. It also has engine braking in manually selected 2nd gear.
I did have some unwanted help from my 5 year old grandson while assembling the rods and springs in the valve body. I got it all sorted out but may have mixed up a couple of the springs.
I did triple check the OD band and actuator rod when I installed it, so I am fairly certain that this part of the assembly is correct. When driving the van, it drives exactly like it would with the "OD Off" switch engaged. As a matter of fact, I turned off the OD and drove it several miles and it did not generate a fault. It only starts flashing the OD light when driving over a mile or so with the OD switch in the normal mode. It also has engine braking in manually selected 2nd gear.
I did have some unwanted help from my 5 year old grandson while assembling the rods and springs in the valve body. I got it all sorted out but may have mixed up a couple of the springs.
#5
No I dont think the problem is going to be with the direct clutch, the direct clutch is on in 3rd and 4th, if it was too tight there would be a bind up shifting from 2nd to 3rd, or too loose there could be a flare shifting into 3rd.
When the transmission shifts from 3rd to 4th the 3-4 shift valve moves and turns off the forward drum and applies the overdrive band. So if the overdrive band was the problem it would feel like a neutral during that shift because the forward drum released. Since you don't get a neutral during that shift that is telling me that the 3-4 shift valve did not move. I believe the problem will be in the valve body, in particularly the 3-4 shift valve itself.
If the shift solenoids had a problem you should have a problem in another gear as well. For 1st gear the #1 solenoid is on, 2nd gear both solenoids are off, 3rd gear #2 is on and 4th gear both are on.
When the transmission shifts from 3rd to 4th the 3-4 shift valve moves and turns off the forward drum and applies the overdrive band. So if the overdrive band was the problem it would feel like a neutral during that shift because the forward drum released. Since you don't get a neutral during that shift that is telling me that the 3-4 shift valve did not move. I believe the problem will be in the valve body, in particularly the 3-4 shift valve itself.
If the shift solenoids had a problem you should have a problem in another gear as well. For 1st gear the #1 solenoid is on, 2nd gear both solenoids are off, 3rd gear #2 is on and 4th gear both are on.
#6
Thanks for the great explanation James. I will drop the pan and pull the valve body this weekend and see what I can find. I may have put a spring in this valve that is the wrong size by mixing it with another one. I have them all nicely segregated during the cleaning, but my grandson got into them and had a blast playing with them. Almost all of the parts only fit in there respective ports, so I sorted that part out pretty well, I hope. But a couple of the springs were pretty close in size and I did not have a good reference for them all.
Do you by chance have the images shown above for all the valves? Or a link to an on-line reference?
Thanks again for such a great answer.
Bob
Do you by chance have the images shown above for all the valves? Or a link to an on-line reference?
Thanks again for such a great answer.
Bob
#7
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#8
James, you are awesome. I had the van on jacks and was letting it drain out when I read your post. I printed a copy and took it out in the garage where I used it as a reference. I pulled out every valve and verified that they matched your diagrams. The only thing I found wrong was the the 3-4 shift spool was installed backwards. So now we know what happens with you do that.
I got it all back together and it now shifts perfectly through all the gears.
Thanks again for all your help.
I got it all back together and it now shifts perfectly through all the gears.
Thanks again for all your help.
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