Cummins automatic trannys

I’ve had/have RFE trannys behind hemis and Cummins. Change the fluid at 10k, 30k, 60k, 100k and you’re golden. Too bad manufacturers lie and have people maintain their trucks on a schedule so they will fail early. Bad luck here and there on trucks will take out even well maintained trucks.

Good luck finding a truck, all the ones around these parts have jacked up motors and tires. It’s crazy how someone would need more than 800 to 1000 ft/lbs or torque to haul kids and groceries 99% of the time. But that tune sure does help when you have that camping trip, doubt a 6.7L stock Cummins could have pulled it.

Scott0700 said:

My 2015 failed at 44k. Six months out of the 5/100 warranty. $6,500 later and it was immediately sold. Never worked the truck hard. Do not ever buy an extended warranty…unless you own a Ram…then always buy it.

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did you change the fluid in 5.5 years you owned it? That’s some old fluid, regardless of mileage IMO

getting the break in material out is my key to healthy transmission. I won’t be doing to my wife’s SUV because I intend to trade it in after three years….. and it will be just another used car that will probably fail on someone around 100k range.

ajparry89 said:

Well that is what I mean is the trick, because its so hard to find one that has NOT been tuned and beat on, etc. lol. I understand that if I come across one then it should be good to go.

yea un-tuned and not messed with is definitely what I am looking for, all that is understood. And yes, the 68rfe in the 4th gens is the tranny that I thought was better. But was that tranny used in the 3rd gens? you said it is used in 2008?

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They began introducing the 68RFE in the 2500 in 2007.5 models.

Burla said:

Myself and my brother both had HO cummins, I went manual out of the gate he went auto. He went through 3 transmissions but he towed heavy. He traded his baby in on another ram but this time he went manual as well. If you never want to worry about a transmission, just get a manual end of story. However, clutches aren't that cheap for a Cummins manual transmission either, but hey it isn't a perfect world. I did love the manual, but my knees didn't, and I ended up getting rid of the truck because of aging knees.

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2018 was the last year for the manual trans with a Cummins. There just was not much demand for them because for the most part people are lazy.

Gr8bawana said:

2018 was the last year for the manual trans with a Cummins. There just was not much demand for them because for the most part people are lazy.

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Or Cummins doesn't want them on the road because they will last forever, lol. No repeat sales. I figured the op already knew the manual was gone and he was looking for an older truck. The interesting thing about the Cummins paired with the manual, it is very user friendly. You can press the brake and slowly let the clutch out without stalling. So when you are on a hill, no chance and slipping back like car clutches, unless you are an idiot, lol. That is the beauty of the Cummins, low end torque and pull that allows this.

Plus on grade or when towing, manuals are really desirable, so sad day they got rid of them imo.

I have owned a lot of trucks in the last 60 years and driven plenty of rentals and company trucks working in the bush for a living. Modern automatic transmissions are much better than the old days. They are great for towing and on hills especially with the new tow/haul mode.

I agree that adding horsepower and not modifying a modern auto trans is a potential recipe for failure.
I also agree that the way you drive has a lot to do with longevity. It is not good to lug even diesel engines, so I use the manual shift control sometimes just driving around the Valley. It is best not to shift from N to D when your vehicle is moving. You can shift with your right foot. Ease up on the throttle when a shift is coming. Towing in steep country is hard on transmissions and generates heat. Watch your gauges and read outs. Just common sense stuff, but I was much harder on vehicles when I was younger.

Yes my budget does not allow me to get a newer truck. I am being patient and looking around for something older and in decent shape. that is why I said its hard to find them not deleted and tuned, because usually by the time they are 12-14 years old or even older, someone has done that to them. And yes, I know they stopped with the manual trans in newer models, but I wasnt worried about that because I cant afford them anyway haha!

IF you can find a truck with maintenance records, and IF they show that the tune is merely to delete and not a HP boost a deleted truck isn't necessarily the end of the world. They're out there if you pay attention to what you're looking for.

For example, I delete all of my trucks but never once have I turned them up. I only delete out of necessity. I've had a few question whether or not I've turned them up, but it's easy to show which tune is on it. That alone isn't always enough, but coupled with a list of receipts for everything I've ever done has made selling/trading my trucks a breeze. There are plenty of others that do the same thing. You can usually tell when you meet someone if you ask the right questions.

Back to the point of manual vs. auto... there's really no benefit to one over the other any longer. The autos will perform just as well as the manuals. I used to be a manual guy, but now there's just no need.

My 68RFE failed with code P0735 a few weeks ago in my 2012 RAM 3500. I'm waiting for a rebuilt but it has a lead time of 60 days.

The truck has < 125,000 miles on it. I am the original owner. I have towed trailers weighing 7,000 to 10,000 lbs for less than 30,000 miles and I have a truck camper on it that weighs 1,500 lbs. The truck was maintained by RAM dealers with all of their recommended maintenance until now but I have recently switched to an independent repair shop for the motor, and now another independent repair shop for the tranny.

My ‘14 2500 6.7 68RFE is tuned & deleted. I have the SOTF CSP5 switch, I daily it with the +40 hp, but also I have a built valve body in it for the high pressure. I didn’t tune it for the power, but because of emissions failure, it was cheaper to delete it than fix the emissions crap

I’m at 86k miles with the only problem on the truck being the 8.4 touch screen and the drag link recall.

ajparry89 said:

Hey all,
Looking for a 3/4 ton Cummins. I’m hoping to find one with a manual trans, but I won’t reject an automatic if it checks every other item on my list. My question is, are there any auto trannys that I should be aware of? Certain years? Some have told me the 3rd gen auto is not that great. Is the early 4th gen any better? It won’t be driven daily, but hard to find them with really low miles in my price range. Thanks for all the help!

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I have 2011 2500 Ram w 68RFE. I drive the truck cross country with a 2000 lb slide in camper on it. I bought an auxiliary trans cooler and have never had any issues. Heat is the killer of these transmissions, so get aftermarket trans cooler with fan. 185K miles on my truck now

ajparry89 said:

Hey all,
Looking for a 3/4 ton Cummins. I’m hoping to find one with a manual trans, but I won’t reject an automatic if it checks every other item on my list. My question is, are there any auto trannys that I should be aware of? Certain years? Some have told me the 3rd gen auto is not that great. Is the early 4th gen any better? It won’t be driven daily, but hard to find them with really low miles in my price range. Thanks for all the help!

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Hi there. I own a 2016 Ram Cummins with 138,870 miles in it. AT. 4x4. I only tow a flat bed 20’ Carson with a Can-Am SXS. Probably 8 times since buying both in 2019. No issues with tranny except once in a while it won’t lock in park and I have to tap the shifter. I change my tranny fluid every 35,000-50,000 miles. Run freeways mostly, average 75 mph. No issues yet. I had an extended warranty to 124,000 miles. Didn’t use it for anything. Change my oil every 5,000 miles. Air cleaner & Fuel filters every 10-12,000 miles.

Problems:
One front and rear turn signal burned out.
Drivers side battery went out at 124,000 miles. Replaced both with Gel batteries.
Def tank was clogged at 65,000, had to be dropped, cleaned, re install. Was using Blue Def and warranty wouldn’t pay. Ben using Mopar Def since.
Front seat seam pulled loose on left side at 81,000. Had them re sewed.
That’s it.

What does Deleted mean?

nlambert182 said:

Back to the point of manual vs. auto... there's really no benefit to one over the other any longer. The autos will perform just as well as the manuals. I used to be a manual guy, but now there's just no need.

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There was a time when a manual would 100% outperform an automatic in just about every form. At one time, I could shift faster than even my buddy's built up Trans Am w/auto, with my '68 Firebird with the Rockcrusher.

Those days are, sadly, gone.

Today, the only reason to get a manual is to get the joy of shifting your own gears.

ajparry89 said:

Hey all,
Looking for a 3/4 ton Cummins. I’m hoping to find one with a manual trans, but I won’t reject an automatic if it checks every other item on my list. My question is, are there any auto trannys that I should be aware of? Certain years? Some have told me the 3rd gen auto is not that great. Is the early 4th gen any better? It won’t be driven daily, but hard to find them with really low miles in my price range. Thanks for all the help!

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The Aisin auto trans with the 5th gen high output Cummins weighs 200 pounds more than the 68RFE in the standard output variant. My understanding is that the 68RFE is a decent trans but one has to every so often take that dip stick out to smell it, to see if the fluid has burnt. My 2019 is easy to monitor as it has a digital display of all vital systems incl trans temp. Maybe lean toward a 68RFE that has a digital trans temp display.

Once and for all......The 68rfe IS NOT a bad transmission.

Many other folks have chimed in that it is the guys who tuned thier trucks that had transmission issues with the 68. Those dudes experiencing failures never addressed the transmission too when uprating the engines power.

The problem is that the transmission computer logic in the 68rfe was flawed and never corrected by the OEM. The big block 6.7 Cummins is making max torque / power at very low rpms and the 68 likes to get shifted quickly into 6th gear for MPG improvements. This is a very bad combination when tuned and pulling a load, especially lifted and on bigger tires, as it puts too much power on longer physical levers through the 68rfe at just the right time for failure.

My tuned 2013 68rfe 3.42:1 ratio'd, levelled on 37's truck has towed a 10K pound trailer all over this country and Canada...primarily in the high steep mountains of the West. Truck has been tuned and deleted since 1300 miles old...but I also tuned, properly cooled and maintain the transmission and I have had zero power related driveline failures in 100K miles of driving. Only a seized front pinion due to an error committed by an auto technician from a shop I won't name because they stood behind me and made it right.

A transmission cooler, higher line pressures, and particularly "adjusted per gear converter lockup" are critical to maintain the 68 behind a tuned Cummins 6.7 A deeper transission pan with a magnetic drain plug is good insurance as is regular maintenence and sane driving tactics go a very long way to keeping your transmision alive.

I would not shy away from a 68RFE equipped truck if the price, mileage and condition were right.

Cheers;
Ch

nlambert182 said:

If you get a 2008+ 2500 with the Cummins you'll get the 68RFE. You'll get a few naysayers with it, but typically when you see a major failure people have tuned/deleted the truck and cranked up the horsepower. It's not designed for any more horsepower/torque than what it left the factory with. Treat it right and you'll get years of trouble free service from it.

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I know a guy with an '04 3500 qclb with a heavy **** utility bed. It's used for concrete cutting. Stop and go and freeway use. It had 364K on the drivetrain when I saw him 6 months ago. 68RFE from birth aside from a valve body and a seal. Normal wear items are kept up. No extra filtration. Nothing.

I have an 03 cummins with a 48re. It's currently at 292k miles. I haven't owned it since new but got the truck off a friend who believed in maintenance. Changed the transmission fluid and filter every 30k. Fuel and oil filters every 5k oil once a year no matter the miles. One year he would put 15k on the oil the next year only 5. Truck has it's original injectors and high pressure pump. It has zero blow by and it shifts great. Granted it wasn't worked hard. Only towing a snowmobile trailer and a popup trailer. The only thing I would worry about with the 3rd gens would be checking the front end. With the miles most of them have, you would want to check maintenance history. Not that it's overly expensive to replace everything, but it it will be a few grand if you are paying someone to do the work for you.

68rfe is fine if it hasn't been beat on. I tow with mine in 5th gear unless pulling long and flat and light. 6th gear is a little bit dinky. With a load, 3.42's behind it and a big motor in front of it, full retard downshifts for 6th to 4th like it will do, and dropping into 6th right before another grade to Downshift again is bad for it.

I never liked the logic in tow haul mode. It'll shift to 6th past 65mph basically no matter what, and try to hold it up to 25ish lbs of boost on a grade, and then go full throttle down to 4th and obviously accelerate like mad, and then start upshifting again. It's kinda ******** if you don't lock out 6th while towing.

I have a 2015, bought the extended warranty, so far haven’t needed it, I tow a camper (travel trailer) no tranny problems, running like a champ

2003F350 said:

Yeah FAR too many people think you can just throw a tune on a modern diesel and hammer away on it.

It's not like the old days when transmissions were built to handle vastly more power than the engines they were coupled to could put out in stock form. You used to be able to take a 350 out of a car, put a 502 big block with the same (or a similar) TH400 transmission, and things would hold together. You can't do that today.

These days they keep costs in mind 95% of the time, so the transmissions have been redesigned to handle what the stock setup can put out and that's about it. It allows them to use less expensive materials to keep their costs down and profits up. Then when you throw a tune on it and grenade the trans, they can deny the warranty claim.

On really ANY modern driveline, if you're going to start making big horsepower and torque, more than the engine was rated for, you HAVE to spend money on the rest of the driveline. That means big upgrades to the transmission, probably the transfer case, and you may want to look into the gearing too just to be safe. ONLY after that can you be somewhat sure you can shred the tires without blowing up something expensive.

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The old days were definitely before the 99 Superduty 7.3 diesel with the the 4R100 tranny , terrible transmission. Shifting issues , overheating Couldn’t drive 10 city blocks towing stop , and go without it overheating . Mine got a little better when I installed the 6.0 transmission cooler .

My 2014 3500 Ram 6.7 with the 68RFE will definitely run warmer towing the mountains in hot weather, but no where near that 4R100. I’ll see 195-200 on a long pull or city stop , and go towing . Running empty pretty consistent 172-176 .

To the OP , sure we see the 68RFE with issues on these forums , but it’s a very very small percentage of how many there are out there .