RPM's seem high

[chuck4x4nc]

I went through 500 break in on new 3500. Then 500 mile light, slow towing 300 miles. The truck was running around 1600 rpms at 70 mph. Around 1250 miles the Rpm's went up to around 1950 at 70 mph towing light (12k). I called dealer and they said transmission learns and adjusts, ok I get that but why the 300 rpm increase? Now loaded or unloaded 70mph = 1950 to 2000 rpm. This is my 3rd 3500 ram diesel and I rent them from enterprise every couple of months. Always 70 mph towing = 1600 to 1750 rpm. My other trucks were 3:42 & 3:73 and rentals were 3:73. So my question is with 68rfe and 4:10's on completely stock dually with 17's what rpms are you seeing loaded and unloaded at 70 mph. Dealers have no clue and are really useless. Also why would rpm range change after break in?

 

[Rockcrawlindude]

The rpms at a given speed don’t change unless you are in a different gear. The only thing that could be happening is you are in a different gear. Maybe you have tow/haul mode on?

Edit: did you change tire size?

 

[H3LZSN1P3R]

The RPM does not sound to high for what gears you have, with that little but of rpm difference id be thinking the TC lock up is not locking i never paid attention to mine that close but it could be normal during trans learning

 

[MikeXM]

Sometimes the transmission has a mind of its own. On the same trip, on a very flat surface and same constant speed, it will be running in 5th while other times it is in 6th. No apparent reason why. It's just what it does.