12 Valve Engine and Drivetrain Talk about the 12V engine and drivetrain here. This is for 1994-1998.5 engine and drivetrain discussion only.

Torque converter locking in Hi at 45mph

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Old Oct 7, 2007 | 07:03 PM
  #1  
racinrex's Avatar
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Torque converter locking in Hi at 45mph

is it natural for my 95 to lock the torque converter at 45MPH in hi? I mean to get it to unlock I have to slam my foot almost to the floor... then its a fine line between un-locked torque converter and a full blown downshift to passing gear.

at 55mph with it locked my RPMS are only like 1300 rpms. so at 45 its GUTLESS when the TC is locked.
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Old Oct 7, 2007 | 11:34 PM
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From: Garrard county, Kentucky
Yes, that is how they work. It's a lot better with an aftermarket TC, but it really is a bad mph to have lockup programmed in at. If you want it to unlock the TC, tap the brake pedal, and it will unlock. You can wire in a switch pretty easily to keep the TC unlocked if it really bothers you.

Eric
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Old Oct 8, 2007 | 03:32 AM
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13FOX's Avatar
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From: Texas
Those 12v auto and programmed that way to use the low rpm torque from that engine. Very normal. As stated above, tapping the brake will take it out of lock-up.
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Old Oct 8, 2007 | 10:01 AM
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infidel's Avatar
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From: Montana
Actually the factory lockup is set for 47 mph.
I had my PCM reflashed back when my truck was new to change lockup to 55 mph.
Unfortunately most dealers no longer have the equipment and knowledgeable mechanics who can do this reflash.
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Old Oct 8, 2007 | 02:06 PM
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winkle's Avatar
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From: Escondido, Calif
I found this post that may help you out to change your shift points.

https://www.dieseltruckresource.com/...&highlight=tps


I try to insert a picture of the wiring I got off this site if I can.
Attached Thumbnails Torque converter locking in Hi at 45mph-tps_potentiometer_1_3.jpg  
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Old Oct 8, 2007 | 02:44 PM
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Cummins4Life's Avatar
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From: BFE Oregon
Just turn OD off until you are over 50-55mph.
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Old Oct 8, 2007 | 11:42 PM
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From: NC
I get a shudder around 45-50mph locked in OD. Ive got used to hitting OD off while in the city. One of these days Im gooin to to play with the tps.
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Old Oct 11, 2007 | 07:55 AM
  #8  
racinrex's Avatar
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The more I learn the more it sounds like this truck is actually doing almost everything propper. Might be time to put the juice to it.
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