OK, so my Duraheap is getting old and it's time to replace it, and high on the list is a 2012 3500 RAM with a 6.7L and 6speed manual, crew cab long bed 4x4 (same config as my Chevy). I'll be towing trailers ranging from a couple thousand pounds up to something bigger than the truck's tow capacity which is 13,400.

First question: how troublesome is the factory DMF? My Duraheap went through 3 in the first 90K miles. The dealer is telling me it's not a big issue on the Ram. True or not?

Second question, how well does the stock clutch hold up? I understand it's a 13" clutch, right? Most I've ever got out of a single disc clutch in my Chevy has been 60K on the factory original. I have yet to get more than 30K since then. Two SBC's and a Valeo. Modest power increase (Edge box on level 1).

Next question: fuel mileage I should expect with this configuration? My Chev is around 19 empty. I'e seen 20+ several times, particularly in hot weather. Towing mileage depends heavily on the weight of the trailer but it drops substantially.

Last question: what if anything can be done to "delete" without using a tuner that can be detected? Can, for example, sims be attached where the exhaust sensors go and a straight pipe be substituted? No emissions testing where I live but losing the warranty due to a tuner being detected is not acceptable. I don't need more power anyway, the 350hp/650lb-ft is plenty.

I've done lots of reading but I find it hard to find answers here just because of how it's organized.

TIA

 

Mine is a 2011 3500 crew 4x4 dually with 3.43 gears. I was not sure about the 3.43's when i got them, but not bad so far. If i had to do it over again I would get the 3.73's. You will not get that kind of mileage out of the Dodge, I get 13 average overall. I have pulled upwards of 20k and it pulls it fine. Does not like 6th gear on the interstate pulling much over 10 so I run it a little slower and in 5th and it will do whatever I want. I have 31k on the truck so far in 7 months and I use as my daily driver work truck. The clutch feels just like it did the day I bought it but I am easy on it though.

By the way, what is DMF?

 

Thanks for the response, I was starting to think I asked a taboo question or something.

DMF = Dual Mass Flywheel, essentially a 2-piece flywheel with spring action between the two pieces. They're known to be troublesome and failure prone at least in the Chevys. They do a good job however, of isolating the transmission from engine vibrations and harmonics. For as long as they last.

Aftermarket clutches generally replace the DMF with a Single Mass Flywheel (SMF) and a sprung hub clutch disc instead to isolate the transmission. It eliminates the flywheel failures but you get something called "gear rollover" which is essentially a growling sound from the transmission at low rpm/high load.

So I'm really just wondering if the stock flywheel in these things is as troublesome as the Duraheap's. And how well the stock clutch holds up as well with stock power.

Anyway I took the plunge and got the truck. Mine has 3.73's. The dash showed me getting 13's on the way home on the freeway running 75+. I stopped, disconnected the EGR, and went about 40 miles with the cruise set on 68mph and averaged about 18 per the dash. I need to do a more controlled test to establish how much of that improvement was the EGR disconnect versus the lower speed. If I can get high teens with this thing I'll be a happy camper.

Disconnecting the EGR did make the CEL light come on, but it's pretty subtle, just a small icon down in the lower left corner of the dash. If that's the worst side effect, I can live with that.

Really what I'm mostly interested in is deleting as much of the emissions crap as I can without using a tuner which will void the warranty. I don't really mind hooking up the EGR and swapping the DPF and cat converter back in if I need to take it in for warranty service.

So to anyone out there, if I swap in a straight pipe in place of the cat converter and/or dpf, and don't load a tune to what happens? Is this just a matter of a CEL light coming on? Or is loading a tune essential to make it work properly? I'm really only interested in the MPG increase anyway, not concerned about adding power. I've read too much about head gasket issues, and stock is enough power for me anyway.

 

The manual trucks are de-rated to 350/625 because the clutch is the weak link. Southbend makes a dual disc clutch (3250 that DTR sells) That you'll need sooner rather than later. You will also NEED to read this thread as you will probably end up deleting and losing your warranty. https://www.dieseltruckresource.com/...t-t278158.html You also need to research the "soot" issue, sooner than later and also get the CCV out of the turbo inlet. Buying the truck was just the first step.

 

The G56 is rated at 350/610, not 625 or 650.

The DMF is still an issue, but at stock power and smart driving you can get a bit of miles out of them. My dad is at 80K on his 06 with his smarty Jr on SW1 and mostly towing miles. Add much more than 40hp and plan on getting a new clutch ASAP.

Mileage will not be that good with a stock motor, 17 on the fwy would be great.

 

Yep, 610, my mistake. I'm not concerned about 610 instead of 800, it's horsepower that gets the trailer up the hill. A big torque number just means it can make it's power with less rpm.

Thanks for the info on the DMF. I will not be tuning this truck, although I am very interested in a DPF delete. The truck has plenty of power and I do not want to put something on it that the dealer will detect and void my warranty with.

So far in my reading, the only way I've identified to delete the DPF without using a traceable tuner is something called a "DPF-R", but I'm having a heck of a time finding any real detailed info on it. It sounds like it comes with sims for the temp sensors that prevent a regen, and a box that hooks to the OBD-II port, and at start-up it goes in and clears the codes associated with a missing DPF. I also read it clears the code associated with an unplugged EGR valve, although I'm not sure that's a good thing. I think the idea is to let it throw codes but clear them and turn off the CEL.

Since it's only clearing codes like any common OBD-II scanner, and not "tuning" the motor, I can't imagine it leaves a calling card for the dealer to detect. Sounds reversible and undetectable to me, except possibly by some indirect means ("hey your truck hasn't done a regen in 20,000 miles!") which I'm not worried about. Not my fault if it never regenned.

If anyone has experience with the DPF-R, especially on a 4th gen, I'd sure like to hear about it.

 

I've got 20,000 miles on my 2011 with the G56...deleted since 3400 miles. No clutch slippage or other issues so far and I do tow a 10K lb. fifth wheel camper frequently up and down the hilly NEPA highways.

I tow on mild tune, do not abuse the throttle or hot rod the truck at all. I believe if these G56 vehicles are driven sensibly the clutch will last a long time.

Before this truck, I had an '01 with the HO Cummins and an edge EZ. Lots of towing as well and still had the original clutch after 265K miles.

 

I'm only at 36000 miles on my 2011. Milage is at 17 mpg. No issues yet other then death wobble but the dealer fixed it.

My uncle on the other hand with a 07.5 with a G56 is at 110000 miles and still the factory clutch... Dodge just replaced all of his dpf and egr, it was all plugged up. I would hate to see the inside of his engine.

 

[QUOTE=Grand Geek;3103317]I'm only at 36000 miles on my 2011. Milage is at 17 mpg. No issues yet other then death wobble but the dealer fixed it.

Are you deleted? Haven't seen people coming close to this kind of mileage stock.

 

I have a 2012 4x4 quad cab long box with 3.73 6 speed manual.
I see 600km /372miles to a tank. 140liters/37 gallons.

This truck has no low end power.
Above 2000rpms and it has lots of get up and go and it is awesome. But to get up there takes some time.
If I had to buy a new truck again I would buy the new automatic. But I should have kept the 05.
I know I do not like running my engine between 2-3000rpm, seems a bit high to me. But this is where this truck really shines.. As for low end torque getting off the line I would look elsewhere.
Milage is crappy 10mpg around town and 13.5 on the highway. I have yet to tow anything more the 5000lbs behind it so I cant give you a good towing milage.

 

Thanks for the responses guys.

What I'm taking away is that the factory clutch and DMF aren't nearly as worthless as the Duraheap's. Might last awhile That's good. The Chevy's was crap and the aftermarket single disc units gave me a lot of trouble too. The aftermarket SMF's also caused a lot of vibrational kinids of noises from the ZF6. My 2012 with G56 is quiet as can be and I like it. If the clutch & flywheel holds up reasonably I'll stay with the factory DMF.

I just got back from my first long tow with this new truck. I was pulling 5500-6000lbs. I hate to admit it, but my 2002 Duramax would easily out-tow this CTD and get better mileage in the process. I got right at 12mpg. Downshifting on hills, too, where the Chevy could pull loads this size with essentially no downshifting.

That surprises me, because the Chevy is only rated at 300hp, and I had an Edge box but I never took it off level 1 which is only 40hp. So 340hp from the Chevy was running circles around my 350hp Dodge.

I'll lose the DPF and see if that helps. I hate to put a tune on it though. The thought of blowing head gaskets and having no warranty to cover it is not a good one. Shouldn't need to do it anyway. If I can just get back to the Chevy's performance I'll be happy.

I've got no complaints about the bottom end power, in fact it seems better than the Chevy. It pulls a load away from a dead stop better. It's the hill climbing performance I'm disappointed with. For now.

 

The way the 6.7 is tuned for emissoins (and really this started with the 04.5 5.9) the difference between 1950 and 2050 rpms is HUGE in terms of ability to maintain speed.

You mentioned earlier that hp keeps you moving, not torque. This is very true, the OEM tuning just doesn't make enough hp sub 2K rpms, that's where the new HO comes to play.

A mild tune and delete are said to do wonders for the sub 2K pulling power.

 

03, how many miles do you have on your 2012? My '09 was a gutless hog until around 15,000 miles after that it was like somebody flipped a switch...night and day. Smooth and effortless power all the way up, felt more like I was driving a 5.9L than a 6.7L at that point. Truck was stock, never modded. These trucks are meant to last and take time to break in and towing helps shorten the process, I attribute my truck's transformation to a 1,500 mile trip pulling around 8K.

 

Well, on this trip I just got back from, I was towing 70-75mph, which is above 2000rpm. Didn't matter, the thing would start up a hill and the rpm would start dropping and I'd have to downshift. On the same hills pulling the same load, my old Duramax would just go straight up in 6th gear with the cruise set without slowing down.

Bottom end power, though, say from idle up, taking off with a loaded trailer, etc, it actually feels stronger than the Duramax. Seems like I had to wind the Duramax up to make power, where this Cummins pulls right off idle. It just doesn't have enough power above 2000, which is where I'm at while towing.

I gotta get it sorted out, I spent too much money on this new truck to be slowing down for hills.

 

I just run the Smarty Jr on stock or 40hp tune. Mechanically, the truck is bone stock. I can feel the difference and the Jr disables the EGR electronically, just changes the parameters to call for 0% EGR all the time. I am potentially taking the warranty into my own hands, but the truck is MUCH more drivable and I believe I'm limiting the soot into the intake (haven't pulled the intake yet). Reads and clears codes and allows me to correct the speedo for my oversize tires, too.
I've heard the Overdrive trans tune from H&S and the Copilot from ATS both control the trans but allow better power transfer so it feels like more power. No personal experience with these. Yet!