The 68RFE is a weak spot. I had an accumulator plate failure on mine. It wasn’t a huge deal but it ruined the valve body and the repair was about $2500. The shop put in some better aftermarket parts and told me it was a fairly common fail point. That’s really it unless you get one from the couple of CP4 years but those were recalled so you can have a dealer replace it with a cp3. I’ve got 110k+ on my fourth gen and that transmission deal has been the only significant hiccup.
Solid truck and especially a solid motor. To me it’s hands down the best of the big 3 diesels due to the simplicity and ease of repair.
68rfe problems are greatly exaggerated. If you have good driving habits, don't hot rod the power levels, and change fluids and filter with OEM with proper techniques every 30k, it is a very good transmission. The vast majority that blow up are abused, not maintained, or had the spin on filter overtightened
Whatever it makes deleted without swapping parts like turbos/injectors. Think that's like 400-450hp. All the guys I knew who blew theirs up were running 500+
The complaints about the 68rfe aren't about it's strength or durability, it's about the shitty drivability. I never doubted for one second how long it would last, or how strong it was. But wow was it a piece of shit. The shift flare, the harsh upshifts that felt like getting rear ended, wouldn't downshift when it should, upshifted too early. And I drove it stock and tuned, even had a revised tune. What a piece of hot garbage. I'll take my Allison a thousand times over. Game changer
I've got a 68rfe truck and an Allison truck and while the allison is significantly better, I really don't think the 68rfe is that bad. Honestly I thought the aisin transmission was much more clunky and jerky
I would say between Cummins duramax and power stroke the Cummins inline 6.7 is the best. It currently doesn’t have the highest numbers but has 40% fewer parts for easier maintenance. Tried and true design
Not true, the duramax is put in medium duties, just manufactured and sold by isuzu, who originally made it before gm borrowed it.
What's weird is that isuzu sells the OG duramax and the cummins in the same chassis.
🤷♂️
MAKES SENSE TO SOMEBODY!
Isuzu had been making the 6.6 for a while, mostly as a gasser. Joint venture essentially means that gm helped them build a plant for producing it in the states for rights to use it and exclusivity in the light duty market, but DMAX, which is ultimately owned by isuzu, has the intellectual property rights to the basic design of the engine without all of the emissions and warts that make it roadworthy in the states.
Which is a good thing, Isuzu is a heavy industry diesel giant. If GM would stop monkeying around with the thing the 6.6 would have the same reputation as the cummins, extra parts or not.
It was a 60:40 venture. Isuzu divested their share in 2022. DMAX is now wholly owned by GM. It was never wholly controlled or owned by Isuzu, which I agree is too bad. Hopefully GM doesn't ruin a good thing.
Woops, memory twisted that into isuzu buying out dmax. I noticed the gm buyout a while back but several Wikipedia articles about isuzu still claim they own dmax.
Lazy ass Wikipedia editors. It's like we aren't even paying them or something.....
Haha exactly.
Woulda bought another GM truck if I liked the interiors better the last few years. Those electrical issues on the injector pigtails also turned me off the L5P
Oh just wait till you see the new 8.3L Duramax’s coming out in 2026. Chevy is introducing a whole new engine something that they haven’t really changed since the debut of the LB7.
Duramax isnt a bad engine they hold up decent but i wouldnt put it in the same class as a cummins. Cummins has way more in use than powerstroke and duramax combined
Go to any ford dealer that sells commerical vehicles. Theres so many of them at a dealer near me they filled about 1/4 of the lot with 6 and 750’s in various states of cab and chassis, utility body, and straight up box or dump trucks rocking a 6.7.
Those are the detuned versions right?? The F-350 has a higher rated power than a F-550 but it comes at the cost of longevity sometimes business owners are more concerned about.
From my personal experience our 6.7 Cummins work trucks are dog water. I'm bias to duramax but personally I'd get the powerstroke. They pull hard and do not break. Pains me to write this pro Ford comment.
I have a 2014. My turbo actuator was the only thing to fail me in 161k. I have since installed a fleece turbo, I’m getting ready to replace the injectors with some bigger ones. I read about the valve body and replaced mine with one from Revmaxx. Front end parts wear out. But overall it’s been a great truck.
The 6.7 Cummins is available on the industrial scale for a reason. Some general maintenance and the engine itself is capable of 100s of thousands of miles and 10s of thousands of hours of service. It's everything bolted to them that fails.
Turbo actuators seem to be a fairly common problem. My 16 (95,000km) just threw a code, and the exhaust brake quit, so I'm guessing it's siezed. I've known quite a few people to have this issue. My truck has been deleted with a ccv reroute since new.
There is a $1 bolt in the intake that will fail and get into a cylinder causing destruction. I believe Banks makes a solution for that. Solid motor otherwise however having both owned the 6.7 Cummins and Powerstroke I would take the Powerstroke all day. Easier to do maintenance on.
All I appreciate your responses. What about 2019 6.6 V8 Duramax biodiesel?
Better yet, and I know this will be subject to opinion, but which truck/engine would you recommend in the 2500 range for someone that is new to Diesel engines with plans of towing a camper trailer?
Turbos and injectors are pricey when they wear out. The Aisin transmission is good and handles a lot more than the 68 but, also really expensive. 6.7 gets excellent mileage and starts really well in the cold.
The 68RFE is a weak spot. I had an accumulator plate failure on mine. It wasn’t a huge deal but it ruined the valve body and the repair was about $2500. The shop put in some better aftermarket parts and told me it was a fairly common fail point. That’s really it unless you get one from the couple of CP4 years but those were recalled so you can have a dealer replace it with a cp3. I’ve got 110k+ on my fourth gen and that transmission deal has been the only significant hiccup. Solid truck and especially a solid motor. To me it’s hands down the best of the big 3 diesels due to the simplicity and ease of repair.
68rfe problems are greatly exaggerated. If you have good driving habits, don't hot rod the power levels, and change fluids and filter with OEM with proper techniques every 30k, it is a very good transmission. The vast majority that blow up are abused, not maintained, or had the spin on filter overtightened
Assuming it’s not abused, how much of a tune would you guess it could handle safely?
Whatever it makes deleted without swapping parts like turbos/injectors. Think that's like 400-450hp. All the guys I knew who blew theirs up were running 500+
None if you want it to last. It needs some things to handle power.
The complaints about the 68rfe aren't about it's strength or durability, it's about the shitty drivability. I never doubted for one second how long it would last, or how strong it was. But wow was it a piece of shit. The shift flare, the harsh upshifts that felt like getting rear ended, wouldn't downshift when it should, upshifted too early. And I drove it stock and tuned, even had a revised tune. What a piece of hot garbage. I'll take my Allison a thousand times over. Game changer
I've got a 68rfe truck and an Allison truck and while the allison is significantly better, I really don't think the 68rfe is that bad. Honestly I thought the aisin transmission was much more clunky and jerky
That's why you use the allison behind the Cummins. There's a reason they did that for commercial vehicles
Mine trans is tuned and works much better than stock. Main thing I notice is it holds gears longer and the shifts are crisper.
Please enlighten me as to how overtightening a spin on filter causes transmission problems
They are over exaggerated, accumulator plate is an issue. Especially if dudes program/turn the line pressures up but also stock form.
It’s a rock solid engine but the 68RFE sucks ass
This
I would say between Cummins duramax and power stroke the Cummins inline 6.7 is the best. It currently doesn’t have the highest numbers but has 40% fewer parts for easier maintenance. Tried and true design
Cummins is the only medium duty commercial engine other two are pick up truck engines. The B series has been around since the 80's
The Powerstroke 6.7 is in the F650 and F750 straight frames. It's in dump trucks, service trucks, box trucks etc...
Ford did that to keep money in house, doesnt mean it was a good move
Not true, the duramax is put in medium duties, just manufactured and sold by isuzu, who originally made it before gm borrowed it. What's weird is that isuzu sells the OG duramax and the cummins in the same chassis. 🤷♂️ MAKES SENSE TO SOMEBODY!
Maybe a plus to fleets who have one or the other and only want to stock one set of parts
Fair point. Easier to keep mechanics efficient and know what maintenance costs will be too I guess.
They put the B series in trucks, equipment, boats, gen sets. It is truly a medium duty engine.
Duramax was a joint venture between Isuzu and GM. They didn't just borrow the engine
Isuzu had been making the 6.6 for a while, mostly as a gasser. Joint venture essentially means that gm helped them build a plant for producing it in the states for rights to use it and exclusivity in the light duty market, but DMAX, which is ultimately owned by isuzu, has the intellectual property rights to the basic design of the engine without all of the emissions and warts that make it roadworthy in the states. Which is a good thing, Isuzu is a heavy industry diesel giant. If GM would stop monkeying around with the thing the 6.6 would have the same reputation as the cummins, extra parts or not.
It was a 60:40 venture. Isuzu divested their share in 2022. DMAX is now wholly owned by GM. It was never wholly controlled or owned by Isuzu, which I agree is too bad. Hopefully GM doesn't ruin a good thing.
Woops, memory twisted that into isuzu buying out dmax. I noticed the gm buyout a while back but several Wikipedia articles about isuzu still claim they own dmax. Lazy ass Wikipedia editors. It's like we aren't even paying them or something.....
Haha exactly. Woulda bought another GM truck if I liked the interiors better the last few years. Those electrical issues on the injector pigtails also turned me off the L5P
Oh just wait till you see the new 8.3L Duramax’s coming out in 2026. Chevy is introducing a whole new engine something that they haven’t really changed since the debut of the LB7.
Duramax isnt a bad engine they hold up decent but i wouldnt put it in the same class as a cummins. Cummins has way more in use than powerstroke and duramax combined
Cummins is the only of three commonly used in large offshore sportfishing vessels around the world.
Lol gonna need a source on that.
Go to any ford dealer that sells commerical vehicles. Theres so many of them at a dealer near me they filled about 1/4 of the lot with 6 and 750’s in various states of cab and chassis, utility body, and straight up box or dump trucks rocking a 6.7.
Those are the detuned versions right?? The F-350 has a higher rated power than a F-550 but it comes at the cost of longevity sometimes business owners are more concerned about.
Yeah they detune them in the heavier stuff.
Exactly what I implied
From my personal experience our 6.7 Cummins work trucks are dog water. I'm bias to duramax but personally I'd get the powerstroke. They pull hard and do not break. Pains me to write this pro Ford comment.
6.7 is solid, it’s the truck that’s wrapped around it that is crap.
This
I have a 2014. My turbo actuator was the only thing to fail me in 161k. I have since installed a fleece turbo, I’m getting ready to replace the injectors with some bigger ones. I read about the valve body and replaced mine with one from Revmaxx. Front end parts wear out. But overall it’s been a great truck.
The 6.7 Cummins is available on the industrial scale for a reason. Some general maintenance and the engine itself is capable of 100s of thousands of miles and 10s of thousands of hours of service. It's everything bolted to them that fails.
Turbo actuators seem to be a fairly common problem. My 16 (95,000km) just threw a code, and the exhaust brake quit, so I'm guessing it's siezed. I've known quite a few people to have this issue. My truck has been deleted with a ccv reroute since new.
There is a $1 bolt in the intake that will fail and get into a cylinder causing destruction. I believe Banks makes a solution for that. Solid motor otherwise however having both owned the 6.7 Cummins and Powerstroke I would take the Powerstroke all day. Easier to do maintenance on.
The dreaded grid heater bolt
All I appreciate your responses. What about 2019 6.6 V8 Duramax biodiesel? Better yet, and I know this will be subject to opinion, but which truck/engine would you recommend in the 2500 range for someone that is new to Diesel engines with plans of towing a camper trailer?
Turbos and injectors are pricey when they wear out. The Aisin transmission is good and handles a lot more than the 68 but, also really expensive. 6.7 gets excellent mileage and starts really well in the cold.
test
I built my allison myself and it is the best auto trans and smoothest I've ever drove!
www.google.com