Cure one problem, created another ...

[Joej27]

On my 98 2500 with a v10 auto tranny, I was having the shaking in overdrive problem that seems to be pretty common. I changed out the plugs, wires, both coil packs ... no help. Then I changed out the Throttle position sensor. That cleared up my overdrive shake issue, but now I have some new issues .... the transmission is staying in 1, 2, and 3 gears up to almost 3300 rpm. Feels like it takes a while before overdrive kicks in. Also, when going down a hill, it feels like its stuck in a lower gear and is causing the engine to brake the truck instead of just kind of coasting.

Any ideas what to throw at it next? Vacuum problem? Crank position sensor? Cam sensor?

 

[Merc225hp]

Did you reset the Pcm? If not do so it needs to relearn.

 

[Joej27]

I unhooked the battery for an hour. No luck. I gave up and dropped it off at a mechanic. Hes thinking transmission speed sensor. Should have some answers in a day or two.

 

[Joej27]

Guy thinks it's a transmission speed sensor and a random vacuum leak.

 

[7091ram]

Sounds like the cable to the transmission pressure valve is not adjusted properly, it's one of the cables that had to remove when you changed your tps sensor

 

[dapepper9]

Staying in gear like that is often a problem caused by the governor pressure solenoid. Try adjusting the tv cable as suggested as well.

 

[Joej27]

It was the transmission speed sensor and my plenum gasket was shot. Runs like a champ now.

 

[dapepper9]

It was the transmission speed sensor and my plenum gasket was shot. Runs like a champ now.

^^Why I hate transmission issues. Learn something new everyday.

 

[Joej27]

At least parts were cheap this round. I feared catastrophic tranny failure when it first happened.