TCC lockup

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Sep 26, 2007 | 11:28 PM

viperrtblck

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Joined: Nov 2005

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TCC lockup

truck has auto trans...built with hd valve body and clutch packs, etc. not sure if problem is chip or not; but while driving and on the SLIGHTEST incline truck will lock and unlock torque converter as it wants; possibly even changing gears...then if no incline or going down hill it's fine..i ALSO noticed that if it's cold out--it wont do it..or it does it less frequent. at times i will be driving and all will be ok; i will let off pedal completely and rpm's will drop a few hundred; go back on pedal and they'll stay that few hundred lower...is this normal? i asked a buddy at work and he said there's a torque converter lock-up solenoid in the valve body..

Sep 27, 2007 | 05:07 AM

ron's power stroke

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Joined: Jun 2006

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From: White Mnt's,New Hampshire

the tc locks and unlocks at 35 to 37 MPH..are you around that speed when it happens???

Sep 27, 2007 | 08:07 AM

mueckster

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Joined: Jun 2003

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From: Damon (South East Texas)

Torque converter clutch solenoid and Trans fluid temp sensor are part of the solenoid pack. It could be possible that the temp signal from the sensor is erratic and causing the changes in TCC lock up. Have you checked for any codes? There may not be any hard codes set that would cause the OD light to flash yet. If the TCC solenoid or the TFT senor are bad, you would have to change the whole solenoid pack assembly. The rpm difference could be related to the TCC unlocking and locking at a low enough rpm where there is normal TC fluid coupling "slippage".