6.4 owners

[mowin]

Just a thought if you are considering buying a new Ram. Maybe wait till the late 2015 production is out. Hoping we may get surprised by Ram on what is standard gearing and maybe even engine and computer mods??? 2014 was the first year that Ram had this 6 speed trans and also the first year for the 6.4 hemi in the truck. As for the dealers, very few in the dealership, at least here in the Rockies, have pulled much and none with the new engine and such, hoping that Ram will listen to it's 2014 customers for what can be improved. Truly, I believe that tweeking both computers would make quite a difference. Not that I would like to have terrible milage, but on anything over 1500 series, milage isn't even calculated. Loosing 1 or 2 mpg and being able to pull as a truck should to me would be preferable.As it is, the computer wont allow anything over 1/2 throttle in any gear but first. The engine is very powerful if given a chance. ie, pulling in low where more than 1/2 throttle can be given, pulls quite good even at low rpms. With the 3.73 gear, pulling on steep grades, 8% and up, can be an experience. If you are lucky, or "unlucky" enough to get to about 50 mph (will easily go that fast in 1st without over revving) and somehow get into 3rd gear, "Watch Out"!!! If you over accell. , it will downshift and NOT into second. It will hit first at about 6k. Believe me when I tell you, it will spin the rear wheels when it hooks up and that is with 13 plus k behind it. Will make your blood run cold. It only did that once and that was with only about 6 k on the truck and not broken in. It pulled so hard that it snapped some of the front body panel screws on the 5'er. Since putting in the 4.56, I don't have to run the high rpm's or push the truck to pull. Was worth, to me, every dime. Did have a few discussions with Ram concerning that. I do know that they listened at least as far up the chain as I could get. I did appreciate that.

I would like to know where you got the "as it is, the computer wont anything over 1/2 throttle in any gear but first" from?

 

[KarL45]

Yes, probably, knowing what I know now, would have elected for the 6.7 with the 4.10 gears. Have driven about every American made truck from Ford, Ram and GM but up until now have not had the towing experience of anything over 3 or 4 K. Definitely would get the 4.10 gears with the 6.7 though. Before having the gear change, Dodge suggested that I talk to the local trans specialist concerning the trans computer. As of about July of last year, they had nothing available to modify the shift speeds. In the process of talking with them though, had another person contact them with the same concerns only was running the 6.7 with the 3.43 gears. Standard gearing at least in my area. The way the transmissions are geared, would suggest the lowest gearing available. Think I would even go that way at sea level. Never know where a vacation may take you. lol

 

[loveracing1988]

Just a thought if you are considering buying a new Ram. Maybe wait till the late 2015 production is out. Hoping we may get surprised by Ram on what is standard gearing and maybe even engine and computer mods??? 2014 was the first year that Ram had this 6 speed trans and also the first year for the 6.4 hemi in the truck. As for the dealers, very few in the dealership, at least here in the Rockies, have pulled much and none with the new engine and such, hoping that Ram will listen to it's 2014 customers for what can be improved. Truly, I believe that tweeking both computers would make quite a difference. Not that I would like to have terrible milage, but on anything over 1500 series, milage isn't even calculated. Loosing 1 or 2 mpg and being able to pull as a truck should to me would be preferable.As it is, the computer wont allow anything over 1/2 throttle in any gear but first. The engine is very powerful if given a chance. ie, pulling in low where more than 1/2 throttle can be given, pulls quite good even at low rpms. With the 3.73 gear, pulling on steep grades, 8% and up, can be an experience. If you are lucky, or "unlucky" enough to get to about 50 mph (will easily go that fast in 1st without over revving) and somehow get into 3rd gear, "Watch Out"!!! If you over accell. , it will downshift and NOT into second. It will hit first at about 6k. Believe me when I tell you, it will spin the rear wheels when it hooks up and that is with 13 plus k behind it. Will make your blood run cold. It only did that once and that was with only about 6 k on the truck and not broken in. It pulled so hard that it snapped some of the front body panel screws on the 5'er. Since putting in the 4.56, I don't have to run the high rpm's or push the truck to pull. Was worth, to me, every dime. Did have a few discussions with Ram concerning that. I do know that they listened at least as far up the chain as I could get. I did appreciate that.

The 66rfe was introduced for the 2012 model year, not 2014. The 68rfe was introduced in 2007.

 

[wyo2track]

Just a thought if you are considering buying a new Ram. Maybe wait till the late 2015 production is out. Hoping we may get surprised by Ram on what is standard gearing and maybe even engine and computer mods??? 2014 was the first year that Ram had this 6 speed trans and also the first year for the 6.4 hemi in the truck. As for the dealers, very few in the dealership, at least here in the Rockies, have pulled much and none with the new engine and such, hoping that Ram will listen to it's 2014 customers for what can be improved. Truly, I believe that tweeking both computers would make quite a difference. Not that I would like to have terrible milage, but on anything over 1500 series, milage isn't even calculated. Loosing 1 or 2 mpg and being able to pull as a truck should to me would be preferable.As it is, the computer wont allow anything over 1/2 throttle in any gear but first. The engine is very powerful if given a chance. ie, pulling in low where more than 1/2 throttle can be given, pulls quite good even at low rpms. With the 3.73 gear, pulling on steep grades, 8% and up, can be an experience. If you are lucky, or "unlucky" enough to get to about 50 mph (will easily go that fast in 1st without over revving) and somehow get into 3rd gear, "Watch Out"!!! If you over accell. , it will downshift and NOT into second. It will hit first at about 6k. Believe me when I tell you, it will spin the rear wheels when it hooks up and that is with 13 plus k behind it. Will make your blood run cold. It only did that once and that was with only about 6 k on the truck and not broken in. It pulled so hard that it snapped some of the front body panel screws on the 5'er. Since putting in the 4.56, I don't have to run the high rpm's or push the truck to pull. Was worth, to me, every dime. Did have a few discussions with Ram concerning that. I do know that they listened at least as far up the chain as I could get. I did appreciate that.

I have the 6.4, 4.10 set up and live above 7200 feet. Very intrigued by your gear swap to 4:56 as I have thought about this myself and have calc'd some rpms. I have been a real happy camper with my truck, but I can see how it would really help in higher altitudes. Even in tow haul and towing only 3000#, there are times where the truck just doesn't want to shift out of 4th gear and get into 5th where I think it should, (i.e. flat grades). I think 4.56 would really improve the performance of the 6.4 at my altitudes. What kind of rpms are you now running at 60, 65 and 70 mph in 6th gear?

 

[regularcab2500]

I weigh less than most of you guys but ive never had these issues with strange shifting and i have 3.73s. In town it holds the lower gear longer but on the freeway it basically will only kick down to 4th for a second then immediately go to 5th for as long as i need it then back to 6th in tow/haul. I didnt even have these problems the one time i towed a 10k# enclosed trailer at work down the 290 on the *********, windiest day last summer (just found out the trailer is overloaded and is 6000# past its gvwr [emoji33] and the axle is bowed )

But for the record karl, if you went with a cummins youd probably be doing a gear swap anyway because you can only get 3.42s with the diesel unless you get the aisin.
What are your rpms at 65 with those 4.56s?

 

[loveracing1988]

I weigh less than most of you guys but ive never had these issues with strange shifting and i have 3.73s. In town it holds the lower gear longer but on the freeway it basically will only kick down to 4th for a second then immediately go to 5th for as long as i need it then back to 6th in tow/haul. I didnt even have these problems the one time i towed a 10k# enclosed trailer at work down the 290 on the *********, windiest day last summer (just found out the trailer is overloaded and is 6000# past its gvwr [emoji33] and the axle is bowed )

But for the record karl, if you went with a cummins youd probably be doing a gear swap anyway because you can only get 3.42s with the diesel unless you get the aisin.
What are your rpms at 65 with those 4.56s?

On the highway even empty my truck will not go into 6th gear in tow haul mode. I figured it locked it out.

 

[Ratket]

correct it locks it out

 

[regularcab2500]

Mine runs at 1700 rpms in tow/haul at 65 and 1600 when not..i figure it has to be in 6th because 5th runs at 2100 when not in tow/haul

 

[loveracing1988]

Mine runs at 1700 rpms in tow/haul at 65 and 1600 when not..i figure it has to be in 6th because 5th runs at 2100 when not in tow/haul

Yeah, mine will run at 2100 or so in tow haul so 5th gear. It's weird that yours is different.

 

[Ratket]

it's not.. tow haul locks out 6th gear and mds won't activate. I averaged. 16.5 mpg with 1 ton in the bed with cruise set at 74 tow haul on.

 

[regularcab2500]

One thing i think is weird too is that my 2010 1500 would turn on the manual gear select in tow/haul but this truck doesnt.

But if im doing 50 im at 1100 rpm in 6th..havent gone down the highway with any serious weight though thats probably a factor.

I wish there was someone else on here with an rclb that could verify this stuff..it might have to do with the fact my truck's curb weight is like 600lbs less than all of yours. Idk...

 

[Ratket]

if the tow haul is on u are not in 6th

 

[regularcab2500]

It just doesnt explain why its at that low of rpm..everyone is reporting much higher rpms than me in the "highest gear"...do you guys have 4.10s? I have 3.73s. That would make a couple hundred rpm difference i think.

 

[wyo2track]

With 4.10's, at 65 mph ~1725 rpm in 6th; drop it to 5th bumps up to 2225. Essentially about a 500 rpm difference.At 70 mph, those rpm are approximately 250 higher. Using a ring&pinion, rpm, speed, & tire size calculator, with my 33" tires, there is only a 250 rpm difference going to a 4:56 r&p. Would really like to know real world rpm with a 4:56 r&p as these trucks are so damn reigned in and controlled with the stock programming.

 

[regularcab2500]

Well while driving down the thruway today around 60mph i decided to put the tow/haul on to make sure im not and although i was going slightly uphill the whole stretch, i was at 2300-2400 rpm the whole time and it wouldnt shift out of 4th at all! At that point i tried letting it get to 5th and wouldnt...not sure whats up but i'll have to drive down the highway a few times this weekend

 

[67Guzzler]

Hi. Reading a lot of questions about towing with 2014/ 15 2500 with 6.4 engine. Purchased one in Apr of 14. Wanted to tow 27' toy hauler, 13k. Everything on the lot, approx. 50, had the 3/73 gear. While the engine has amazing power, the transmission computer wont allow it to be used without excessive downshifting. This is something that you can't tell from a test drive unless you tow a bumper hitch type trailer. I elected to tow a 5th wheel so until the hitch was installed, had no idea. Right now I will say this, if the dealer has no 2500's with the 4.10 gears on the lot, order one. Don't care if your pulling much or not. The facts, with 3.73 gears, 6th gear, at 80 mph, your engine will tack at 1800 rpm. With the computer shift program, you will constantly be shifting just driving down the road with little grade or a slight wind. The advertised power band of the engine starts at 4000 rpm. At 3k, it will start to gain some power. Even using the "tow haul" mode, it is geared too high in my opinion. Maybe if you live and drive only at sea level, and don't tow at all, you will be happy with the 3.73. I finally went through Dodge and got a gear change. Went from 3.73 to 4.56. Cost approx. $4,000 but cheaper than trading or buying a diesel. Best money I ever spent. Now pulls like a truck. Fuel mileage is the same in town, about 2 less on hi way, and in hilly country the same or better. 400 plus miles over and back from Denver (Vail Pass) at 70 plus mph, averaged 15.5. Was also carrying the slider hitch and 250# generator, (700#). Love my truck. I can give more towing details with the std. gears if anyone is interested. Ps. have heard of those with the 6'7 Cummins with the 3.45 gears having the same towing, shifting problems that I experienced. Thanks

I know this is nearly a two year old thread but I wanted to thank the poster above. I ordered a 2017 6.4L Hemi 2500 4x4 on 11/19/2017. Scheduled build is 12/10/2017. I ordered with the 4.10 rear after looking at the final drive ratio on the 66RFE and thinking that a 4.10 isn't really a 4.10 with THAT much overdrive. I appreciate the feedback above.

-Guzzler

 

[CDN Ram]

Congrats on the purchase. I'm sure you'll be fine with the truck you bought. But I will tell you I LOVE MY CUMMINS!!!!!

 

[67Guzzler]

Congrats on the purchase. I'm sure you'll be fine with the truck you bought. But I will tell you I LOVE MY CUMMINS!!!!!

Thanks!

My last 6 trucks have all been CTD's. A 1994, 1996, 2004, 2005.5, 2010 and 2013.

I agree 100% -- The HEMI is no comparison to the CTD for towing / torque / heavy pulling.

Just wanted to go GAS this time.

-Guzzler

 

[nukegm]

11,000 miles on my 16 2500 6.4

only issue is the totally *** clutch fan.

3 so far.

other than that i love the truck.

it really " woke up " at around 9000 miles.

cheers!

 

[Bigdaddy]

I have no regret getting mines with the 4.10 gears, I have a TT that is at about 9k and it tow it with no problem the tongue is about 930 lbs.