I just got back from a 500 mile round trip and had my trans shift kind of strange about a half dozen times. At highway speeds at about 70+ mph when I'd accelerate to pass someone, it would downshift, but before engaging in the lower gear it would feel like the trans would disengage then re-engage - no high revs, but a definite "thunk" sound like putting the truck in gear at higher than idle speeds. It was almost like it forgot or got confused what to do, then it remembered. It didn't do it all time, but like I said, it did it about six times and once at in-town speeds at about 35 mph. It hasn't done it since I've been back home. The conditions were flat roads, no grades, and about 85 degrees - not extreme conditions.

Has anyone out there experienced this?

 

My trans is still doing this, but less frequently. It's almost like a tranny slam, but while moving.

Anyone else notice this with their truck?

 

There is a flash update for general peformance,engine/trans.May want to see if your falls into that range needing a computer update.

 

According to my dealership my truck is up to date in all the latest flashes/downloads/updates.

 

Ya so did mine say that, I have now a new dealership that I use for service. They are happy to have me so far LOL. But I don't go in for stuff like look screws and anything I can fix myself for free. I do however tell them then next time I go in for service and they put it on the record of the truck. If you change out your radio or whatever you should have it recorded on the VIN it's also proof for your insurance.

 

Mine does the same thing. I think it is the torque management kicking in at weird times. It is weird, it feels almost like it shifts halfway and then the rest of the way. Or like the rear end shifts (I know it really isn't) and the tranny. Only on full throttle downshifts at highway speeds. Another weird thing it'll do is when I'm accelerating from stop or up the on ramp properly (WOT!) it feels almost like the tranny is slipping or the engine is missing. I know this isn't the case cause the trans temp never really gets past 145 and the fluid doesn't smell at all. That's why I think it's got something to do with the torque management system.

 

I just noticed mine do it now that you mention it. I didn't feel it was too abrupt, but could feel a definite shift.

 

My truck has done all of the above, what sucks is that these problems are intermittent. It seems like as soon as I go near the dealership they mysteriously go away. The service rep told me that unless the tech can reproduce the problem, there is nothing they can do. So I am planning on dropping in and taking the tech (by force if necessary) for a test drive when the tranny is acting up. The only common link I can think of is heat. My tranny seems to freak out after long drives on hot days.