[F-1Rodder]

I have a '97 Jeep Grand Wagoneer with an overdrive electronic automatic transmission. Whenever it shifts from 3rd (not overdrive) gear into the overdrive gear, the engine speed jumps up about 200 rpm and then about a second later or maybe 2 seconds, the rpms drop 200. If I shift it down from overdrive into 3rd gear (you do this by pressing a button on the dash board) the same thing happens, it shifts and engages firmly but the rpms are about 200rpm higher and then quickly drops back.

So what is happening? I don't think it is the torque converter slipping because this all happens well above the stall speed. Is it some sort of lock-up feature engaging?

This is not a problem question, but I would like to understand what is happening.

[Frisco]

Hey F-1 how are you?

I have a Plymouth Voyager with the three speed trans. It has the same button on the dash to turn the "OD" on or off. The shifter bezel has a circle around the "D" to indicate overdrive. Since your Jeep is also manufactured by Chrysler, I assume it to be the same or similar to what I have.

What we have is NOT true overdrive (although it feels like it shifts four times) but an electrically controlled lock-up converter. I don't notice the increase in RPM when it 'locks up'. It just feels like the trans has shifted one more time.

Hope this helps.