I have a 98 12v cummins. We had trans rebuilt last year by a friend who does this for a living. After having that done, we had a bunch of work done on throttle assembly, new cable , tps, bellcrank, linkages and misc. Diesel mechanic said to leave the kick down cable unhooked because it was worn out , trans guy was not very happy. Anyway had another linkage problem, goes to diesel mechanic again and get truck back. One way home, truck has a problem getting out of first gear. It falls flat on face, if you let of throttle and it kicks into second gear, it seems to bang through all the other gears lke a rocket. So we call trans guy to have it check and serviced. Trans guy says nothing wrong with trans and its all set up properlly. However he said it is throwing a tps code something along lines of set high. He said to bring back to diesel mechanic. I have spent too much on this. I trust trans guy more than diesel mechanic. Anything you guys can think of!

 

You will kill the trans if the kickdown linkage isn't adjusted correctly. Diesel mechanic shouldn't have to touch the TPS for any reason........ I would probably trust the Trans guy more, he should be able to diagnose and get TPS voltage back in line if that is indeed the issue.

 

I had an '81 Dodge gasser that I drove around for a couple years with the kick-down linkage disconnected. Let's just say I didn't do the clutches any favors. Replace the cable if it's worn, it's cheaper than a trans rebuild. Trust me.
Your first gear problem sounds like a bad governor pressure sensor or solenoid - ie not enough governor pressure to make the shift, then too much governor pressure when it does shift. When the trans was rebuilt, were the governor sensor and solenoid replaced?.
You can check TPS voltage yourself if you have a multimeter and don't want to spend more money....
http://www.dodgeram.org/tech/transmi...TPS_adjust.htm

 

Tranny man is the correct one you do need the kick down/throttle cable hooked up for things to work correctly. The TPS and cable need to be set to factory specs for things to work right on a stock truck.

When things get modified (more HP or higher rpm range,raised tranny line pressure) then things change and need to be compensated for/adjusted accordingly.

A good trans person will know how to adjust/set up the tranny to work with the engine changes.

As has been said running without throttle pressure or kick down link is a recipe for tranny destruction. Unless it has been setup and used for wide open throttle drag racing only upshifts then you can do without.

The TPS (voltage changes) tell the computer how hard you are pushing the skinny pedal so then the computer knows when to tell the tranny to upshift depending on the addition input from a few other parameters. The newer the truck the more complex and numerous the inputs.