Transmission problems
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Transmission problems
My problem is the rpms are varying about 300-500 rpms while driving.At first it was only occuring when in overdrive but has since been occuring in other gears also.I think the torque convertor is not locking correctly but wanted some other opinions on this.It does not always happen but when it does I can sometimes fully press the throttle and run at full load for about 10 seconds and it will steady the rpms.My truck is a 92 F150 that was originally a 300 inline that I converted to a 351 with E40D.
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Joined: Nov 2004
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From: Indianapolis
I had the same problem in the AOD in my 1990. Added 1 full bottle of Lucas Transmission Fix. That was 2 years ago. No problems since.
If you have not used it before, don't be surprised when you turn the bottle over and nothing happens. It doesn't pour out, it sort of "globs" out if you know what I mean.
Hunt4Fun
If you have not used it before, don't be surprised when you turn the bottle over and nothing happens. It doesn't pour out, it sort of "globs" out if you know what I mean.
Hunt4Fun
Fleet Owner
Joined: Oct 2005
Posts: 20,789
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From: Kentucky
500 rpm is the exact increase in engine speed when I shut off the OD around 55MPH on my '92 F350. Take a look here: E4OD Diagnosis Thread
The computer uses TPS input, MLPS position and a few other variables to determine shift points. Pull the codes to see if your ECU is trying to tell you something. Not all errors codes will turn on the Check Engine Light.
The computer uses TPS input, MLPS position and a few other variables to determine shift points. Pull the codes to see if your ECU is trying to tell you something. Not all errors codes will turn on the Check Engine Light.
Fleet Owner
Joined: Oct 2005
Posts: 20,789
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From: Kentucky
It's part of the solenoid pack. Not ea$ily changed. 637 indicates an open circuit. Check your solenoid pack connector. Clear the codes. See if it comes back.
Fleet Owner
Joined: Oct 2005
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From: Kentucky
This thread might help: FullSizeBronco.com - 78 - 96 Ford Bronco offroad club, forums, tech, installs
Pins 7 & 8 should be the Transmission Oil Temperature sensor. Anything over 897K ohms is considered an open, which throws the 637 code. Normal range is .8K to 100K ohms depending on the temperature. I would try cleaning the connectors really well, then making sure you have some type of resistance on the TOT sensor pins. The pin-out listed in the thread may be for the newer style solenoid pack. The connector and pin-out changed around 1995. This sensor sends the trans. oil temp to the ECU. If the ECU thinks the trans. is cold it may be going into a cold temperature shift program which may be unlocking your converter.
I would highly suggest a Ford Service Manual/EVTM to troubleshoot this one further.
Pins 7 & 8 should be the Transmission Oil Temperature sensor. Anything over 897K ohms is considered an open, which throws the 637 code. Normal range is .8K to 100K ohms depending on the temperature. I would try cleaning the connectors really well, then making sure you have some type of resistance on the TOT sensor pins. The pin-out listed in the thread may be for the newer style solenoid pack. The connector and pin-out changed around 1995. This sensor sends the trans. oil temp to the ECU. If the ECU thinks the trans. is cold it may be going into a cold temperature shift program which may be unlocking your converter.
I would highly suggest a Ford Service Manual/EVTM to troubleshoot this one further.
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Thanks for the input,Especially RLA2005 your troubleshooting guide got me in the right direction.Turns out the plug on the trans where the harness goes was full of water.After cleaning with electrical contact cleaner and air and then filling with dielectric grease to prevent further water injestation there are no more problems.
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From: Indianapolis
Thanks for the input,Especially RLA2005 your troubleshooting guide got me in the right direction.Turns out the plug on the trans where the harness goes was full of water.After cleaning with electrical contact cleaner and air and then filling with dielectric grease to prevent further water injestation there are no more problems.
Hunt4Fun
