Tranny Problems after Sonnex Install

[jonwright]

So I installed the shift kit and Sonnex stuff in my '03 250 crew 4x4. Ran fine no problems.

I'd say 1-2k miles later or so, now it doesnt' want to shift into overdrive and/or lock the torque converter. When I am accelerating onto the freeway the RPMs will rise and not shift. If I turn OD off the RPM's drop a bit (but I don't feel it down shift) then when I turn OD back on it will shift.

If I let off the throttle completely it will not shift into OD.

I'm just not sure where to even start.

 

[CHPMustang]

First things I'd check is the fluid level hot while idling to make sure it's in the crosshatch.If that doesn't fix it I'd change the fluid and filter being it's less than going to the transmission shop but I'd like to hear of some other options as well.

 

[jonwright]

Yeah, that's pretty basic stuff there. It's very intermittent. But when it does it does it consistantly for a bit. Not sure what "fixes" it for the long(er) term, like shutting off the engine or what. It's just now getting hotter temps here so I'm wondering if that has anything to do with it now that we've gotten to a 'cool' spell.