DEF system issues

[18CrewDually]

If you got the money and want to be safer towing with a 3500 with a Cummins by all means don't let the def system be the deciding factor. Most common issue is the heater but I never had an issue nor do I know anyone personally that has.
Actually I have bigger concerns for the hemi trucks with lifters failing and manifolds leaking over a diesel truck. And the diesel towing hands down gets way better fuel mileage than the hemi not that it is a main deciding factor in the purchase to me.

 

[Jbgarrison6]

If you got the money and want to be safer towing with a 3500 with a Cummins by all means don't let the def system be the deciding factor. Most common issue is the heater but I never had an issue nor do I know anyone personally that has.
Actually I have bigger concerns for the hemi trucks with lifters failing and manifolds leaking over a diesel truck. And the diesel towing hands down gets way better fuel mileage than the hemi not that it is a main deciding factor in the purchase to me.

So are the heaters more susceptible to having issues than the def system. How expensive is that repair?

 

[18CrewDually]

So are the heaters more susceptible to having issues than the def system. How expensive is that repair?

You'd be under warranty so it wouldn't be a concern. There's youtube vids on the replacement.

 

[Cummins diesel]

You must be talking about being equipped with the rfe to get 21mpg, because my 6.7 w/aisin only averages about 14 at best ( city / hwy combined) when not towing.
hauling 4-6× yr a13k trailer and a 3500 diesel seems like a waste of a truck to me. Of coarse its gonna haul the trailer better and nicer, but for that weight and as little often as its gonna get worked a 3500 6.7 isn't necessary , unless someone just wants a diesel just because

Yes they have the 68rfe but we have a 3500 dually with the aisin and a heavy CM utility bed that still averages 14-16. We pull a trailer with a skiddy or mini excavator about half of those miles. These trucks are definitely happier if they are working hard

 

[Billet Bee]

Yes they have the 68rfe but we have a 3500 dually with the aisin and a heavy CM utility bed that still averages 14-16. We pull a trailer with a skiddy or mini excavator about half of those miles. These trucks are definitely happier if they are working hard

I don't know how heavy your excavator is that your still getting 15mpg, the best i can do pulling our trailer is 8-9mpg, sometimes as low as 7 and that's all highway miles.
Work horses is exactly what they were meant to do to keep a good operating regen system.

 

[Billet Bee]

I’m not clear on what you’re selling. OP has wisely considered a diesel, and you’re steering him to a gas truck, which wasn’t your own choice.

And is this a recommendation to overload a 2500 rather than spend a minimal amount more to get a 3500? How many 2500 diesels have the payload for passengers, hitch, toolbox, and 2400# on the pin?

Yes, many people overload every day and get away with zero consequence. But when specing a brand new truck for a sizeable fiver it’s just silly to even look at 2500’s.

In any case, I’ve put in more than my two cents worth, so I’ll move along. I should know better than poking around in emissions posts, and definitely not into the weight policing biz.

Couple things, I meant to say 2400 pl not pin, i was never over weight and we were always well under the tow rating and just under pl rating. Nobody is recommending to over load anything but these trucks are perfectly capable of doing what there rated up to. We all know they can do more then there rated for but that's each individuals personal choice but going up to the number isn't a issue. I didn't recommend him to purchase a gas 2500 , i recommended he purchase a gas 3500 instead of a diesel 3500. A gas 3500 is more then plenty of truck for only 13k lbs, a diesel 3500 for only 13k Is way over kill, not my opinion just look at the rated specs. Is a diesel going to pull better sure it is but it's not necessary and the op was concerned about def and the regen stuff that comes along with a diesel. I personally look at it like this, I love love love my hohd Max tow diesel 3500 but I wouldn't own one if I didn't require one to pull such a large heavy trailer, the op doesn't need one for 13k trailer , and its not like a gas or diesel 3500 is anymore safe then the other, its the same truck just different power trains.
Back when we bought our 2500 diesel, It was perfect for the 13k trailer we got a yr later , if I had wanted a 3500 like the op does then I would of 100% bought a gasser so I never had to worry about all the regen stuff.
Now if he wants a diesel that's cool but it sounded like he was concerned about it and that's why I recommended the hemI 3500 because its way more then enough truck to haul only 13k once every 2-3 months and you don't ever have too worry or stress about def or any dpf problems for that matter.
No hard feelings I just wanted to make my comments and intentions a little more clear

 

[chri5k]

I see way more threads around Hemi’s eating cams and leaking exhaust manifolds than DEF problems on Cummins. Most DEF repairs are considerably less expensive than replacing a cam and lifters. If the metal from the eaten cam ends up ruining the crank or conrod bearings then you are looking at an engine replacement.
It seems some folks who opt for a Hemi over a Cummins to tow a 5ver end up regretting the decision. RPMs are a poor substitute for torque to move a heavy load. The Cummins exhaust brake is a blessing when hauling a 5ver in hilly country.
I would not let possible DEF issues dissuade me from getting the Cummins again. If the emissions stuff becomes too much of a problem, I have heard hitting a big bump can make it fall off. No way to do without cam / lifters or exhaust manifolds. Though headers do solve the exhaust manifold problem.

 

[crash68]

I don't know how heavy your excavator is that your still getting 15mpg, the best i can do pulling our trailer is 8-9mpg, sometimes as low as 7 and that's all highway miles.

Aerodynamics play a huge part of fuel economy, the bigger the sail and/or the faster one travels, the mpg will drop. There's no where near the surface area on an excavator as a walled trailer.

 

[Jbgarrison6]

As I'm looking, seems that there are way more diesels than gassers. May have to go with diesel. Anyone know how much of a hit you take on payload going diesel over gas? Can't be too much.

 

[18CrewDually]

As I'm looking, seems that there are way more diesels than gassers. May have to go with diesel. Anyone know how much of a hit you take on payload going diesel over gas? Can't be too much.

About 840#s

 

[BossHogg]

As I'm looking, seems that there are way more diesels than gassers. May have to go with diesel. Anyone know how much of a hit you take on payload going diesel over gas? Can't be too much.

I've got a 3500 SRW Cummins 3500, the payload is pushing 4,000 pounds.

I've read the thread and my take is to get the diesel. The exhaust brake alone is worth it when towing heavy and if you are towing in the mountains or foothills, the exhaust brake will be most appreciated. If you frequent the RV forums, the general opinion is once you start pulling north of 12K, it is time for diesel power.

I'm towing a Montana 3790RD, it is a 40-footer with a pin weight of 3,200 pounds and a tow weight of 16,000 pounds. I've read Billet Bee's comment about his fuel mileage and all I can say is the diesel in South Dakota must have a very low cetane rating to get that poor mileage. Towing my fifth wheel I average out to 13 MPG at 65 MPH, the MPG increases when pulling at 55 MPH. I have the standard output Cummins with 3:43 axle ratios and the 68RFE transmission.

My 3500 is a MY 2015 and the only issue I had with it is the rear air leveling system pump went out. When I bought the truck I also purchased an 8-year MAXCare service contract which covered the cost of the pump. If these issues are a concern to you, investigate the Mopar MAXcare service contract.

I was you in 2015, investigating a diesel-powered tow vehicle. If I took to heart everything I read I would not have bought anything, I'd be moving the RV by horse. Then it dawned on me, wait, all I'm reading are opinions, many from folks that do not or never owned a diesel pickup. They were simply repeating, with a twist, what they read somewhere else.

My wife and I spent a summer visiting campgrounds and talking with folks about campers and tow vehicles. The takeaway was simple, you won't be happy pulling heavy with a gas engine. I also noticed the majority of tow vehicles we saw at the campgrounds (in Michigan) were RAM Cummins, followed by Duramax and a few Powerstrokes. Back then, many Ford and GM owners were licking the wounds from the CP4 high-pressure fuel pump used on the Duramax and Powerstroke. The fuel pump had internal destruction sending small fragments down the fuel rails and into the injectors causing 10 to 13 thousand dollars in damages. GM covered the issue under warranty, Ford blamed the owners.

The only way to know for sure isn't possible because we don't know two things, how many RAM Cummins are sold versus the warranty claims related to the Cummins and its components. Like I said, I've had zero issues and I'm starting my 9th year of pulling heavy.

 

[jejb]

You must be talking about being equipped with the rfe to get 21mpg, because my 6.7 w/aisin only averages about 14 at best ( city / hwy combined) when not towing.

But you're driving an HO. The OP has not mentioned he's looking beyond an SO, which would give better mileage numbers.

hauling 4-6× yr a13k trailer and a 3500 diesel seems like a waste of a truck to me. Of coarse its gonna haul the trailer better and nicer, but for that weight and as little often as its gonna get worked a 3500 6.7 isn't necessary , unless someone just wants a diesel just because

I hear you. I went diesel for a small load, but it's our puller. We have other vehicles for running to town, etc. I pull a lot of hills here in the Ozarks and when we go to the Rockies every year. My gas 3/4 ton was not getting the job done. I had to drive it far harder than I felt comfortable doing. The diesel towing experience is so much more laid back.

As far as DEF issues, there have been some SW updates on that. I just had one installed a couple of weeks ago as a recall or update while I was in the shop for the dipstick recall. And it's mostly an issue for folks who live up north. I see the OP is in TN, so probably not much to worry about there.

 

[Billet Bee]

I'm towing a Montana 3790RD, it is a 40-footer with a pin weight of 3,200 pounds and a tow weight of 16,000 pounds. I've read Billet Bee's comment about his fuel mileage and all I can say is the diesel in South Dakota must have a very low cetane rating to get that poor mileage. Towing my fifth wheel I average out to 13 MPG at 65 MPH, the MPG increases when pulling at 55 MPH. I have the standard output Cummins with 3:43 axle ratios and the 68RFE transmission.

That right there explains our difference, our trailer is much heavier, I drive 75mph, aisin tranny, 410 rear end.
Your rfe and 343 make a big difference in fuel, my older diesel ram had the rfe & 343, I could get up 21 mpg without a 13k trailer and 12 with . On my current 3500 I'm lucky to average in the teens mpg while I'm just bee bopping around, of coarse i didn't buy the truck to save fuel but it's interesting how different my mpg are from other postings. Also I don't only buy fuel in sd, were ful time rvers and we've got fuel and traveled In every state across u.s.
Part of my issue is my hiccup on op and so many considering that a 13k trailer is heavy hauling, I mean a 2500 is rated up to 17k so only 13k on a 3500 seems pretty easy if you just go buy the specs. I've done this long enough & just can't consider 13k to be hauling heavy but that doesn't mean that someone else can't consider it heavy I suppose, its all relative to a persons experience level.
All I can speak to is what I've seen an experienced, owned both gas and diesel and I've only purchased diesels to haul heavy loads with and we've never had any dpf issues because we're working the truck the way it was designed to do. Then there's those I've seen who buy a diesel and don't travel long enough or tow enough and it seems like there always the ones too complain about why is my regen doing this or that and had to take it in to have something replaced. So I look at as if I'm not hauling a heavy load then why do I need a diesel, you don't , you want, so then I'd get a gasser and not worry about any dpf issues. Now if someone just wants a diesel then that's cool but it's frustrating when you try to warn someone if they don't drive far enough often or tow enough and then they complain about dpf problems later on.

 

[flashman252]

Ok havent read all the posts but just my .02 after reading about 2 and a half pages so far....
1) Diesel is WAY more comfy to tow with, even if you are only towing 13k lbs.
2) My 2500 is my daily driver and I do 36 mi round trip daily. No issues with regens. I did have a bad sensor in the def system that showed its ugly face at like 3k mi. Covered under warranty, no issues with my system since and I have 35k mi on my 2022.
3) I avg 20 mpg empty. Yep you read that right, and Ill GLADLY post up pics of this. My commute daily is half way at 60 mph and the other half at 80 mph. So it almost all hwy. People have called BS, and some have said I have a unicorn truck, but I dont pound my foot into it, and since adding the pedal monster, i barely feather the throttle now and truck just works. I plan on keeping this one around for a good long time, so no need in abusing it.
4) Towing I see 13-16 mpg. Doesnt matter if its my baby little aluminum duck boat, or my travel trailer, its all the same. I tow lots of hills since I live in rocky mountain country, and winds suck here, so if I have a stiff head wind, I can see that number plummet pretty quick. BUT BUT BUT.....What I can tell you, is try doing that with a gasser.... NO F'in THANK YOU!!!! I know what those gasser engines do on paper, and I know how they feel in real life when I have a 20 mph head wind and a sail of a trailer behind me. You give me that cummins diesel and let me drive comfortably down the road, im done playing around with high rpms and quick shift transmissions, I want all that torque please and thank you.

See where I am going here???? Don't be afraid of the cummins because you hear things. 90% of the time you hear things that are bad. Rarely do you hear about the 1000's of trucks that have 0 issues at all. There are work arounds in every situation, and I am sure there will be a delete in the next couple years for these new ECM's and that will take care of the def system all together. Until then, you have a warranty to get you by for 100k mi. You will love a diesel. Are they a little more to maintain, absolutely but end of the day, when you put your family in the truck, you want to be comfortable and confident when you are towing in real world situations.

 

[BossHogg]

Part of my issue is my hiccup on op and so many considering that a 13k trailer is heavy hauling, I mean a 2500 is rated up to 17k so only 13k on a 3500 seems pretty easy if you just go buy the specs.

The use case for a 2500 or a 3500 in single rear wheel configuration isn't the weight it can tow but the weight it can carry. Yes, a 3500 can be configured to handle up to 30K but the context here is RV.

Tow is specific to one's needs. Mountain towing, full-time towing, frequent towing, and once in a while to a campground two miles away. All this comes into focus when making a choice.

 

[2003F350]

Don't get me wrong I love our Cummins and wouldn't trade it for any other , but the only reason we wanted a diesel is that I haul heavy. If we were hauling anything less then a 20k trailer then I'd get a gasser because its better fuel mileage and fuel price and you never need to worry about any dpf issues or expenses. Diesels with all the dpf stuff are mostly meant for hauling big weight because it needs to get worked more often then 5-6 times a yr. Now you can use a diesel truck and never haul a trailer if you drive for 30 minutes on the hwy once a wk, but again why would someone want to buy a diesel if you don't need one and can't work it enough. As little as your going to be using it to tow only 13k I wouldn't even consider a diesel imho, unless you just want one

I'm gonna stop you right here - I came from a 6.4 hemi to a CTD, and the mileage is a night and day difference. I drive 50 miles round trip every day, sometimes more, and I'm seeing an average of about 23.5 on my diesel (it's all rural 55mph highways). The BEST my Wagon ever got was about 14, maybe a smidge higher. Expressway driving (75 mph) was about 12 in the Wagon, about 20 in the CTD. Major differences between the two trucks is the new one has 3.73's as opposed to the 4.10's in the Wagon, and the engine, both have the 6-speed trans. Otherwise they're similarly optioned. The best I've been seeing out of the newer 8-speed trucks from guys who post about it is 18-20, so I've even got them beat.

I did the math in a post somewhere else, but even despite the higher cost of fuel, I'm going a LOT further so my price per mile is MUCH lower with the CTD than the 6.4. I've also got a higher payload, better towing capacity, etc. etc.

What I'm saying is that if a person wants the diesel, go ahead and get it - but make sure you run it, the DPF (and diesels in general) don't like short trips. They want to RUN, so get 'em out and run them.

 

[huntergreen]

Just want to be safe. Maybe I'm overthinking it.. lol.

diesels have become finicky and expensive to run. Check out the cost of maintenance. Also check out the cost of the def exhaust filter. If you can do your own oil changes and fuel filters change, it sounds like a diesel will work for you. That being said, the hemi would also work. Good luck.

Also keep in mind, I’m a former diesel guy, loved my 5.9 Cummins! So I might be a bit biased towards diesel.

 

[chri5k]

Finicky ??? Hmm, I don't see massive threads on using the "right" oil like for the Hemi. Or some magic oil additive like for the Hemi. Or threads on the "right" oil filter like for the Hemi. These are all attempts to keep the engine from self destructing. I have not seen long threads on doing "special" things for the Cummins to keep it from self destructing. Just do the regular maintenance and it just keeps on chugging along.

Oil changes & filter changes are more expensive for the diesel. However, the OCI is much longer than the Hemi so it averages out closer but no less than the Hemi. Air and fuel filters are more expensive but again the change intervals help to even the cost.

 

[huntergreen]

Finicky ??? Hmm, I don't see massive threads on using the "right" oil like for the Hemi. Or some magic oil additive like for the Hemi. Or threads on the "right" oil filter like for the Hemi. These are all attempts to keep the engine from self destructing. I have not seen long threads on doing "special" things for the Cummins to keep it from self destructing. Just do the regular maintenance and it just keeps on chugging along.

Oil changes & filter changes are more expensive for the diesel. However, the OCI is much longer than the Hemi so it averages out closer but no less than the Hemi. Air and fuel filters are more expensive but again the change intervals help to even the cost.

I meant finicky in the way they are driven. As I said, I like diesel’s, but being retired, my driving is mostly short trips. I would have nothing but regen issues and would be replacing the particulate filter often. They ain’t cheap. As for the self destructing camshaft, wouldn’t the cost of a the Cummins at initial purchase cover the cost of a good rebuild on the hemi ?

 

[Billet Bee]

Finicky ??? Hmm, I don't see massive threads on using the "right" oil like for the Hemi. Or some magic oil additive like for the Hemi. Or threads on the "right" oil filter like for the Hemi. These are all attempts to keep the engine from self destructing. I have not seen long threads on doing "special" things for the Cummins to keep it from self destructing. Just do the regular maintenance and it just keeps on chugging along.

Oil changes & filter changes are more expensive for the diesel. However, the OCI is much longer than the Hemi so it averages out closer but no less than the Hemi. Air and fuel filters are more expensive but again the change intervals help to even the cost.

What about the massive amount of different threads on the cp4 glitter time bomb and also what fuel additives are people using to enhance the lubricity in the fuel. I know it's been recalled and newer models don't cone with it anymore but that's probably been the number topic for 3 years