Yesterday sometime, I lost overdrive. If the water pump go's bad, will that flip the switch off?

I've got more problems than I think I have even begun to imagine. May be time to switch back to driving the Chevy for a while.

No they don't.

What may have happened is there's sensor that prevents the tranny from using overdrive until the engine is warm. Either the sensor or the related wiring may be faulty preventing the tranny from going into OD. How this might be related to a bad waterpump... it isn't really.

Also, based on what I know from various users on the forums the Mitsu auto tranny in the Montero is pretty bullet proof and we rarely hear of them having problems.


I'd check w/ Clay before doing that.:o He's a former Chevy dealer mechanic and I'm sure he'll have some insights for you. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Not meaning to jack the thread, but can I take from your answer that the Mitsu auto is NOT the same as the Chrysler A604 based units found in Chrysler products?

Thanks,
Wagon Master

The Chevy is fine, probably because I haven't taken a wrench anywhere near it. I worked on late 60's early 70's Mack diesels. I am NOT going near that Duramax with my dirty old tools. The Montero and the Chevy get the same mileage, but fuel is back up in the $4.39 range, Gas is under $4. The Montero is easier to get the kids in and out. Right now, and for the past 4...or 6 weeks, the Chevy has been parked in my in-laws driveway with a 6' concrete statue and her 3x3' concrete base in the bed and no way to take it out (in one whole piece)

The A604 is a front wheel drive tranny. Ours is a closer cousin to Toyota trannies.

My concern is that the A606 (rear drive) is a derivative of the A604, and I hoped that the Mitsu unit wasn't.

No. It's uncorrupted.

The OD isnt' switching probably due to a lack of hot water at the coolant temp sensor or switch or whatever they used. You said the water pump is bad, right? If what Ray said is correct, a lack of coolant at the sensor
(whatever the sensor happens to be) would be interpreted as a cold engine.

The A606 is a front drive trans, as well. It's mounted longitudinally a la Intrepid 3.3/3.5, as opposed to the A604 which is transverse in the minivans and cars. Maybe, you're thinking of the A727/A904 3 speeds or the A500/A518 4 speeds? The A500 is essentially an A727 with an O/D unit slapped on the back. Same goes for the A904 vs A518. Like Clay said, ours are completely different.

well, the noise I thought was the waterpump, may be the passenger side top cam pulley, I gotta go get the Chevy cleared so I can take this thing appart. ...And then hunt down every 'mechanic' who ever thought they knew what they were doing on this thing.