I have a 2012 3500 mega 4x4 6.7 and a 5TH wheel weighing about 12k. Coming to a stop, coasting and then accelarating without fully stopping results in a VERY hard downshift to 1st gear. So much so it will break something. 16 Hundred not thousand miles on it. Dodge says nothing wrong with it. Any thoughs?

 

Are you in Tow/Haul when it does it?

 

Yes I was with my 5th wheel, just checking out cab clearences for mega cab so I was not going too far, happened real hard one time.

 

Tow haul is a very good feature and programed well on these trucks with engine brake and electric trailer brake unit. You may have your trailer brake adjusted to tight aswell. But you need to learn how to drive with it because its first goal is to get you stopped and control your load. work with it empty for a while and learn shift points and youll start to love how it works.

 

well definatly NOT any thing to do with trailer brakes was coasting to a stop. Not using any breaks. Was such a hard shift to first I had to check the fith wheel hitch for damage! It was like doing a neutral drop!

 

did you bump the paddle shifter by chance and knock it into first? just trying to cancel stuff out. It will grab pretty harsh especially with high rpm. but i dont think it will go into first on its own in tow haul. Think it only goes into second when decellerating. Might be wrong. Someone else can chime in to confirm. Can you get it to repeat? Or did it just do it once? I know I went looking at christmas lights and descided to stick it low range and just creep... Just about put everyone threw the windshield when it downshifted....Im still getting to learn how to drive an automatic and I still manually shift it! Tow haul works great though. and seems to work much better and less harsh than my 07.5 did. But took me a while to learn how to work with it so it wasnt too harsh.

 

Got to thinking, one thing i remember in the earlier trucks is when coasting and the wheelspeed is slow but moving, the engine n trans are at same rpm as idle and stop, but would downshift while coasting slowly from a higher speed while slowing down and trans automatically returning to 1st during a coast. Think there was a flash to correct slow speed downshifts as the comp thinks truck is at a stop when truck is creeping and shifts to 1st and bam....related to wheel speed calibration or something. Was on early 3rd gen 6.7 trucks but may be a cause here or lead you to the cause in your 12 if that sounds like thats whats happening. Think one of the original many flashes for the 6.7-68rfe in 7.5 or 08 took care of this.. again someone else may chime in here and assist.

 

There is not that many of these trucks out there yet, so of course mopar will always say they dont have a problem. I may be one of the first to have this problem, and it is a problem, does it every time if i duplicate the conditions. I would not be suprised to see a flash in the near future to fix this. my truck was built dec 2011, so one of the first ones.

 

BTW I traded in my 08 F350 6.4 in on this ram. freakin thing smoked like a james bond car, smoke screen! got two tickets for excessive smoke, bone stock 34k miles on it. Blue ovel guys "the smoke is normal"! LOTS of white smoke. O yes and it was paid for! now I have a payment and a Cummins. Hope I did not make a big mistake.

 

Tickets for diesel smoke on a stock truck? Are you in california?

 

My 2012 has never had a hard shift. I have had 20K on the back in city traffic costing up to a stop light and then floor it. Even when I shift manualy it always shifts smoothly.

If your harsh shift only happened 1 time I wouldn't worrey about it.

If my AC worked and the transmission would hold 6th gear without down shifting in manual mode I woudl be happy with my truck

 

Yes I am in California, we have to get our new diesel trucks smogged every two years, from 2 years old on! Im in San Diego. My ford Really smoked a lot. Showed tickets to Dealer, still its normal. The ford really pulles my fithwheel well tho. The trouble with my Ram is it is in 2nd gear till you apply the skinny pedel, or as I like to call it the loud pedel. Then it bangs into gear, all the time just lots worse with load.