94 6.5l shifting problem

03 D-max

Honorary "Tosser"
Apr 29, 2008
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Lowville NY
My uncle has a 94 2500 6.5l that i am thinking about buying. The problem is that it doesnt shift right. About a year ago the trans was slipping so he got it rebuilt and it wasnt shifting right so he took it back three or four times and got a new wiring harness and some sort of new controller that is on the trans its self and still its not right.

When taking off with the truck it will not shift out of first gear unless you let off the throttle and it does the 2nd to 3rd shift way before it should. other than that the trans works good. So i guess i just want to know what else could be wrong with it, and could it be in the tcm?? again i am not very familiar with the 6.5's so any help is much appreciated.
 

Mike L.

Got Sheep?
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Aug 12, 2006
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Fullerton CA
My uncle has a 94 2500 6.5l that i am thinking about buying. The problem is that it doesnt shift right. About a year ago the trans was slipping so he got it rebuilt and it wasnt shifting right so he took it back three or four times and got a new wiring harness and some sort of new controller that is on the trans its self and still its not right.

When taking off with the truck it will not shift out of first gear unless you let off the throttle and it does the 2nd to 3rd shift way before it should. other than that the trans works good. So i guess i just want to know what else could be wrong with it, and could it be in the tcm?? again i am not very familiar with the 6.5's so any help is much appreciated.

Could be a valve body problem or a solenoid. Not knowing what was actualy done it's hard to say. I would have a Tech 2 put on it and see if the commands are coming in on tme for the shift transition or is the command not coming on time. The fact that the 1-2 shift is late we run into a timing problem because when it finaly does shift it is time for the 2-3 shift so they try to double up.