Transmission shifting issues in higher gears

[User_3336]

I've been having issues with my 2019 ram 1500 3.6l bighorn crew cab for some time now. I took my truck to the dealership and they updated all the "new" updates and flashes and it has progressively gotten worse since. I dri e 45 minutes to work and about an hour home due to heavy traffic and construction. The transmission never seems to be in the right gear and is continuously over or under geared for the traveling speeds. I'm not sure if my truck has ever fou d 8th gear for more than 5 seconds at a time. I've got a rear end clunk, shutters, and groaning/moaning from the drive train as well but the dealership says it's fine. Something is not "fine!"

What AXLE RATIO do you have???

 

[stormcom]

I have a 2019 BH 3.6 with shift issues. I live in North Texas and cannot get it to run in 8th gear on the level Lone Prairie at 70 and 75. All my driving is highway with most trips being 50 to 75 miles. I even put a tonneau cover on it and did not help. Dealer said they get winded at 70 and get used to 6th and 7th gear. I drive with the cruise control as much as possible. I hear about TSB's but cannot find them. My vin is KN646224.

 

[1lowcab]

I have a 2019 BH 3.6 with shift issues. I live in North Texas and cannot get it to run in 8th gear on the level Lone Prairie at 70 and 75. All my driving is highway with most trips being 50 to 75 miles. I even put a tonneau cover on it and did not help. Dealer said they get winded at 70 and get used to 6th and 7th gear. I drive with the cruise control as much as possible. I hear about TSB's but cannot find them. My vin is KN646224.

What rearend do you have?
My 3.6 with the 3.55s will run 80-90 in 8th all day, zero problems.