Cummins automatic trannys

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ajparry89

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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!
 

mtofell

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I'm far from brand loyal and over the last 30 years (in order) have owned Toyota, Ford, Nissan, Chevy, Honda and now my Ram. Unfortunately, the Ram has been the least reliable and most notably the tranny. And I don't mean just my experience since obviously, I singularly, mean nothing from a statistical/scientific sense.

Ram trannys pretty much suck and have for decades. I remember as a kid working at a service station back in the 80s listening this Dodge fanboy bragging about how he got 90K out of the tranny on his LeBaron. Even as a dumb kid I knew that was nothing to be proud of. I suppose the 68RFE behind (most of) the Cummins is a a bit better than the 66RFE behind my 6.4 Hemi. I base this on a totally non-scientific study of the posts I read here. The Duramax/Alison tranny in my 06 Chevy was bullet proof and ran like a champ through 150K when I sold. I hung out on Chevy/GMC message boards and can't remember more than one or two problems. Ram? Failures on Ram trannys are very common. Any time spent on this board will tell you that. Valve body failures are most common. My tranny failed and was rebuilt at 38K and 90K and is holding at 130K but shudders and clunks at times. If not for my Lifetime Warranty I would have certainly offloaded this truck for fear of repairs. My engine also failed at 120K but is another story and not something you are asking about (and was a Hemi not a Cummins).

Having been through various vehicles and experiences over the years I have zero interest in owning any FCA vehicle without a warranty. Almost forgot my other data point... the tranny in my company's delivery vehicle - a 2020 Jeep Cherokee, failed initially at 40K but was limped to the dealer and miraculously healed (wouldn't replicate the problem) but then finally failed at 62k.... just as the engineers planned it with the 60K powertrain warranty. Luckily, I had another extended warranty and got it rebuilt.

Lastly, I live an ocean away from my Ram truck and only drive it a week or so every month or two (moved to Maui from Oregon) and my daily driver here is a 2008 Honda.... never a hint of a problem in 15 years of ownership. If only Toyota or Honda would make an HD truck!!
 

nlambert182

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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.
 

Scott0700

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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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ajparry89

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Well I suppose I will keep looking around until I find a manual that checks every box!
 

nlambert182

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Well I suppose I will keep looking around until I find a manual that checks every box!
Good luck.

As I said before... there is nothing wrong with the 68RFE if you use it as intended. It's built to tow. Use it, maintain it, and you're extremely unlikely to find issues. One thing to keep in mind... most people on the internet only post negative experiences. Very few positive.
 
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ajparry89

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Yea I do understand that, definitely. The trick would just be finding one with decent mileage, that WAS messed with and mistreated. haha
 

Scottly

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.....And the manual tranny in the Cummins isn't nearly as durable as the automatics were after 2018, so much so that they quit selling them because they were not rated to take the available torque. The manual had a throw as long as King Kong's reach, and sucked to drive everyday.
 

tjfdesmo

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It's interesting to me that Mopar trans are so hated, yet the only failures I have had were a Ford auto in an Expedition @13K miles, and a Chevy with the hallowed Allison that I lemon-lawed within a year.
 
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ajparry89

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.....And the manual tranny in the Cummins isn't nearly as durable as the automatics were after 2018, so much so that they quit selling them because they were not rated to take the available torque. The manual had a throw as long as King Kong's reach, and sucked to drive everyday.
haha yea I have driven them before, and done some work on them before. Thankfully I will not be driving it daily, haha. Wish I could afford an 18 or up!
 

nlambert182

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It's interesting to me that Mopar trans are so hated, yet the only failures I have had were a Ford auto in an Expedition @13K miles, and a Chevy with the hallowed Allison that I lemon-lawed within a year.
Same here.

We had a trans failure in a 19 Expedition and dad had his Allison go on his mid 2000s GMC 2500.
 

Hemi395

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As previously mentioned, the 68RFE gets a lot of hate because of the people that put 350hp tunes on their trucks and then blow the trans. I have the 65RFE in my 1500 which is also considered junk for the same reason. I have 99k on my truck and it has towed my camper all over the US with 0 issues. Only thing I've done to it is added an aluminum pan and changed the fluid religiously. There are many examples of the 68RFE (and the 65RFE for that matter) with hundreds of thousands of miles on them.

Bottom line, if you're going to use your truck like a truck and maintain it, there is absolutely nothing wrong with the 68RFE.
 

Gr8bawana

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The 68 rfe when used as intended, which includes heavy towing is very reliable. When guys delete and tune for added power all bets are off.
Most threads about trans failures usually end up being because of owner abuse.:superhack:
 

nlambert182

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True statement. And the main reason the Aisin is "more reliable" is simply because you can't really tune them. :) If/when you can tune them they'll start puking too. This is true with any diesel truck with an engine/trans tune.

There is a built in shift flare in the 68RFE that some don't like and think that it's failing when in reality what it's doing is slowly rolling in the torque instead of dumping all of it at one time. They'll install a trans tune that ups the line pressure and removes the flare (fluid coupling) and hit the trans with 850+ lb/ft torque. Yes it shifts harder but is akin to smashing the gears with a sledge every time it does.

When you understand that it was designed to flare to protect the transmission, it's less concerning. I never pay attention to it.
 

2003F350

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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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ajparry89

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No real trick. If the truck is bone stock and hasn't been deleted, assuming it has service records it should be fine.
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?
 

Gr8bawana

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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?
Any actual RAM dealer will not sell a tuned and deleted truck, period. Because it's illegal. So yes stock trucks are out there.
The reason there are so many trucks that are tuned and deleted for sale is BECAUSE of the problems they incurred after being deleted.
 
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Burla

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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.
 

Hemi395

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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?
You may have to go to an emissions state to get a stock or undeleted truck. I know here in MA that's all you can find because everything has to pass emissions. Very rarely do I even see a deleted truck here and usually they're from a different state.

Pre emissions trucks are extremely common here for that reason, I see lots of 12v Cummins and older Powerstrokes.

Pre 2008 cummins trucks I believe had the 545RFE in them for a few years and before that it was 48RE.
 
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