Trans trouble--won't stay in OD--late shifting

[justin146]

I wish that there was a simple fix for this. My buddies '95 Exp. 4x4 EB is havin' all kinds of trouble. His truck will hold the gears out way too long. The 2 to 3 shift(i think) will hold out to almost 5 grand. It also doesn't want to stay in OD on the highway. The OD Off light was flashing until we reset the computer. This started after he reset the computer and put on a new DPFE sensor(check engine light was on). It (od light)hasn't come back on since we reset it 2-3 days ago.

His speedo is jumping, and the gas pedal surges when he uses Cruise.This part has been happening for a while though.

What could be causing all of this trouble?
Could it be the TPS? A speed sensor?
We checked the trans fluid and it appears to be slightly over-full.

 

[Lifted95X]

Your best bet would be to try to pull some codes from the computer.

 

[justin146]

we pulled the codes before we reset the computer. It said that first, third and fourth were slipping. I dont know how this could be unless there is a bad sensor in there--he had the tranny rebuilt less than a year ago. there was also the code for the EGR but the DPFE fixed that.

 

[Lifted95X]

If it was less than a year ago...isn't it still under warranty then?

 

[justin146]

The guy that rebuilt the transmission said that he didnt know why it would be giving that code. I think the code said "Incorrect ratio-1,3,4".The warranty(12k) is out. We had the codes read at the dealership to diagnose the DPFE thing.

 

[TPLYNCH]

Go to Sears or Autozone or another "reputable" place that will do a test of your alternator and charging system. If you alternator is going bad or charging improperly, it can cause shifting problems with the transmisson (electronic). Just a thought.