4R70W Problems

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Old 01-16-2008, 09:17 AM
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4R70W Problems

This tranny is in a 2002 Ford E-250. Started out with torque converter shudder with a moan and I replaced the fluid and filter. Performance seem to improve somewhat. Drove it for 3 months and then the trans started slipping. Could drive vehicle if I shifted thru the gears manually but eventually I lost everything except reverse. Truck will move in 1st gear but it takes a high RPM to do so. Reverse hooks normally. The Tranny # is 1C2P7000HA. The error code was PO720 which is Output Speed Sensor Circuit Malfunction. Replaced that sensor but no difference in performance. Cleared the error code after sensor replacement and its not coming back. I have another , duplicate truck that is also starting to show some tranny problems.....Any assistance you guys can give would greatly be apppreciated!
 
  #2  
Old 01-16-2008, 12:15 PM
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If you had a speed sensor issue, then the transmission was probably operating in fail safe mode while the sensors wasn't working and the code was present. In fail safe mode, the torque converter clutch usually doesn't apply, that probably overheated the transmission and burned up the foreward clutches.

Have you checked the fluid? What's it look/smell like? I will bet its burnt.

Steve
'95 Clubwagon XLT
 
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Old 01-16-2008, 02:43 PM
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It does have a slight burn't smell to it.
 
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Old 01-16-2008, 02:51 PM
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Well, there you go.

Sorry to tell you but it needs an overhaul.

Steve
'95 Clubwagon XLT
 
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