'16 Ram 2500 CTD first tow. Some thing is wrond

[M_R_E_]

My first tow from MI to FL. I towed in towhaul and cruise. couldn't keep speed on small hills. Speed would drop 4 miles before kicking in. Power in mountains was terrible. My old Ford 7.3 would out pull it . Something is wromg. Help

[Me_Again]

I tow at 24.5K GCW with the 3:42 gears in 5th gear and it down shifts to 4th to climb normal mountain passes. It will go to 3th on a windy slower steep pull.

[Bedlam]

goducks10 wrote:

tinner12002 wrote:
Mine rarely downshifts from 6th unless I'm pulling a pretty steep incline with the cruise engaged. It may drop a couple MPH on a hill but cruise and 6th stay engaged. Only pulling about 12K 5th wheel toy hauler @65mph so its not working hard at all.

Big difference between 4.10s and 3.42's.

Agreed. My 4.30's allow me tow in sixth gear and it will shift down to fifth on inclines. The steepest grades will usually pull in fourth unless a lower speed limit warrants a lower gear. This is on a detuned chassis cab typically over 14K lbs GVW and 22K lbs GCW but it will be over 16K lbs GVW and 24K lbs GCW starting this spring and I don't expect much difference.

[M_R_E_]

Thanks to all.

[Cummins12V98]

Start engine, turn on TH and FULL EB every time. Lighter RV tow in 6th on flat land, any hills lock in 5th at 60 you will be at 1,750RPM a perfect pulling RPM. If you see a larger hill coming up drop to 4th before it slows and you loose speed. The computers are good but they can't see ahead of you.

[Hannibal]

I used cruise on all four of my Cummins Rams. My '98 12v was a 5spd/4.10 so it ran 24-2500rpm all day every day at 68=70mph towing or not. No downshift needed or possible. It was a noisy beast. The '01.5 and '03 were just a matter of momentarily stepping on the loud peddle to cause a downshift at the bottom of the hills so it was already in it's power band. Same with my '05 Hemi powered Ram and even my lowly 5.4L F250. If I were deaf and didn't have a tach, I wouldn't know the difference. Cringe is not an engine weakness or transmission problem. :B

[goducks10]

tinner12002 wrote:
Mine rarely downshifts from 6th unless I'm pulling a pretty steep incline with the cruise engaged. It may drop a couple MPH on a hill but cruise and 6th stay engaged. Only pulling about 12K 5th wheel toy hauler @65mph so its not working hard at all.

Big difference between 4.10s and 3.42's.

[tinner12002]

Mine rarely downshifts from 6th unless I'm pulling a pretty steep incline with the cruise engaged. It may drop a couple MPH on a hill but cruise and 6th stay engaged. Only pulling about 12K 5th wheel toy hauler @65mph so its not working hard at all.

[brulaz]

I had a similar reaction to the OP when first driving our new RAM CTD.

When in cruise, the down-shift to 5th is loud and busy, as cruise waits for the mph to drop ~4 mph, it then races to catch up and revs the engine upto ~2500 rpm, before settling down to a comfortable 1800 rpm in 5th. This prolly what I least like about our RAM CTD with the 68RFE.

But there are a couple of options to avoid this:

The simplest is to stay in cruise and lock out 6th as soon as you hit the hills. This is what I and most others do.

Or you can manually downshift to 5th. The transition is much smoother with no high-rpm flare if you downshift at the base of a hill before the mph drops. But it's too much trouble for me, especially on long trips in the hills.

[alexleblanc]

My 2013 F250 works similar losing about 3-4mph but it had the 3.31 rear gears, from what I read it's less of an issue with the 3.55's. It's not a preoblem with your truck, it's more of a situation where you are running at a slightly less than optimal RPM for the power curve. I've driven plenty of vehicles over the years and it seems with lower gears of today it's more of an issue on cruise. The worst offender I found was the previous generation Suburbans with the 5.3 and I believe 3.08 rear gears ( I could be wrong on the ratio) they were a dog on cruise and would drop nearly 8-10mph in the hills. We always end up with one as a rental on our family winter vacation it seems, 6 years and counting!

In my case when I run about 60-62 on cruise I lose about 3-4mph, if I run about 65-68 I lose 1-2, at slower speeds I simply would put my foot down to cause it to downshift right before the hill.

[Threebigfords]

blofgren wrote:
As others have said it sounds like you need to lock out 6th to keep your RPM's somewhere around 1900-2100. That is the sweet spot for the Cummins and it will pull like a train.

My combo is great in that I sit right in that range in 6th gear right around 65 mph so I can actually pull my 16k fiver up some pretty good grades without downshifting and it will actually accelerate up the hill if I give it some more throttle. Trust me, your new truck has MUCH more pulling power than your old 7.3L, it will just take getting to know it better to get it out of it.

Please let us know how you make out!

Uh....that depends a lot on what he had done to the 7.3

My last modified 7.3 would put any brands new stock truck to shame for pure pulling power...brakes, comfort, stability....that's a whole nother story!

[blofgren]

As others have said it sounds like you need to lock out 6th to keep your RPM's somewhere around 1900-2100. That is the sweet spot for the Cummins and it will pull like a train.

My combo is great in that I sit right in that range in 6th gear right around 65 mph so I can actually pull my 16k fiver up some pretty good grades without downshifting and it will actually accelerate up the hill if I give it some more throttle. Trust me, your new truck has MUCH more pulling power than your old 7.3L, it will just take getting to know it better to get it out of it.

Please let us know how you make out!

[cummins2014]

Searching_Ut wrote:
I always lock out 6th gear on my Ram while towing. The Asin transmission tends to hunt bad, especially between 5th and 6th. I've also found cruise control costs me almost 2 miles to the gallon while towing so I turn it off often and it allows a fair bit of speed variation in rolling hills. The gear ratio in the SRW's is fairly high, which in my opinion works fairly good as a compromise for when you're running empty at 80ish MPH on the freeway unload in 6th, but still have 5 useable gears for towing. I'm not sure where the claims of seven up steep hills comes from. Mine drops down into 3rd pulling hard fairly often, as did my 2011 2500 with regular output engine towing a trailer that was only 8k. Most freeway pulls you can keep freeway speeds as they only get up around 6 or 7 percent grade most of the time. Mountain highways often get much steeper.

.

With my 2014 Ram with just over 13k fifth wheel I can pull Daniels at the speed limit 60 mph in fourth gear, have never yet seen third gear on any grade yet that would allow me to go at least 50 mph, and that includes the hill out of Ashton Idaho into Island Park

FYI to the OP my 99 7.3 with a bunch of mods would pull the same hills mentioned above with the same fifth wheel down in second gear at 30-35 mph compared to the Ram at 60 mph in fourth gear. Yes something is wrong ,your driving or the truck

[KeithAS]

I have a 2010 Dodge 3500, pulling 1100-1200 lbs. I use tow haul in towns, but turn it off otherwise. I usually use cruise control on the road. As a hill becomes steeper, speed will drop 3-4 mph below set speed before a downshift. On downhill grades, as speed increases, the speed may go 4-5 mph over before a downshift. I consider it normal. Down long 6% grades with curves, I will usually adjust the cruise down several mph below my usual 59 mph set speed.

[IdaD]

I don't use cruise when I tow, or really much otherwise. Maybe that's it?

I've towed over the western Rockies and Sierras and have yet to encounter a situation where I couldn't accelerate at will. Something may be amiss.