Fair enough. I completely agree with your description of how a dealer would likely 'handle' the problem. I did think about adding a couple other ideas mostly having to do with the engine not the tranny but didn't take the time to include them since you're still within the warranty period. Oh well - here goes - My other ideas had to do with a. engine performance and b. vacuum leak/computer issue. Believe it or not little tune up issues like a malfunctioning sensor, slightly off ignition timing or poor fuel delivery could result in nearly identical symptoms to those described above. Not saying that those are the problem - it's just that a whole host of things can produce similar symptoms so keep an open mind.

The other thought (part b.) was that in older models (before electronically controlled transmissions were the norm) the transmission had a vacuum line from the engine. Now days I believe they are nearly all electronically (computer) controlled. It used to be that something as simple as a vacuum leak would often mess with the shift points making the transmission shift weird and also bog down the engine idle a bit so that it would not roll forward on its own or roll backwards on a hill etc. these days it’s more likely to be a software issue where something needs a software update.

So when you take it in – don’t forget to mention that you think the engine is down on power as well – they may find that needs something like a simple software upgrade but it could just as easily be a faulty sensor on the engine.

I can’t accurately answer your other questions about does the truck roll forward on its own (yes, mine does) or backwards on a hill (no, mine doesn’t) because mine is an older (2000) and idles around 750 rpm – which is plenty enough power to hold the truck steady – it is possible that newer models may have a slower idle speed but I’ll let someone with an newer model respond.

-Saturday