66RFE Lifespan

[mtofell]

As important as maintenance, etc. is, there is a certain amount of luck with these (or any) trannys. For all of you that have installed things to keep it cool and/or are changing the fluid and tight intervals, mine crapped at 38K under zero load with VERY few towing miles. It crapped again at 90K under similar usage patterns. I guess my point is just because these trannys are treated well doesn't mean they won't fail.

Sure, maintenance is important but I wouldn't count on that entirely to manage the risk of things going wrong. I'm sure my experience is not typical but I'd personally sell my truck rather than own it without a warranty. I'm at 130K and have been through two trannys and an engine.

 

[TorqueWagon]

My wife’s uncle just bouth a 3rg gen cummins and not a month later the transmission pooped out on him. Truck had around 150k. They took it to a reputable repair shop and they said nothing good about that trans. They also said “They ALL”, meaning any Dodge transmission, go out around 150-180k, “if you work them”.

My truck has the 6.4 and the 66rfe, running 35” tires, steel utility/hay spear flatbed, with about 125k on the clock, that is my work horse on the weekends, and I started getting concerned. So, I got online and started doing research. I have seen more than a few posts about the 66rfe and its problems. However, I also got to wonder if having the truck regeared would help save the transmission. My truck has been running 4.88s since 75k miles, which is about when I started really working it. So, while I’m sitting here wondering how much life my transmission has left in it, I saw where someone posted and pointed out that you only see the problems when you search online, so you never know how many are out there running problem free.

So that got me to thinking, how many 66rfes are there running high miles problem free?

How many people have had problems even though they modified their drivetrain?

How many miles was on it when the trans died?

My 68RFE died at about 190k miles. I do some towing, but not a lot. I tow a dump trailer at 10k pounds locally-short distances maybe 10 times a year. 7k travel trailer maybe 2000 miles a year. ordinary driving habits, nothing high power or extreme. I took great care of it and kept it well fed and relatively cool. I do think that the factory cooler is inadequate. I added an additional cooler. I had the trans rebuilt/upgraded and it failed again at about 250k. I think the pump failed and it overheated. The pump was not changed out the first time, so it may have been an "old" condition that got it the second time. I understand That in my 2007.5 Ram, the 68rfe design was new, and not all that mature and perfected. Some say the 6.7 Cummins engine is just too powerful / torque-ey for the 68rfe, but I don't think I drove in such a style to blame it on that. Anyway, I got rid of that trans and got a built aftermarket.

 

[U&A]

Spot on.

No matter what you do there is always a level of risk regardless of the steps you take to reduce risk.

we just need to hope the efforts put in pay off over time. They don’t always though, do they.

Life is a risk. Keep on keepin on.
Joe Dear-tay

As important as maintenance, etc. is, there is a certain amount of luck with these (or any) trannys. For all of you that have installed things to keep it cool and/or are changing the fluid and tight intervals, mine crapped at 38K under zero load with VERY few towing miles. It crapped again at 90K under similar usage patterns. I guess my point is just because these trannys are treated well doesn't mean they won't fail.

Sure, maintenance is important but I wouldn't count on that entirely to manage the risk of things going wrong. I'm sure my experience is not typical but I'd personally sell my truck rather than own it without a warranty. I'm at 130K and have been through two trannys and an engine.

 

[Dusty]

My 68RFE died at about 190k miles. I do some towing, but not a lot. I tow a dump trailer at 10k pounds locally-short distances maybe 10 times a year. 7k travel trailer maybe 2000 miles a year. ordinary driving habits, nothing high power or extreme. I took great care of it and kept it well fed and relatively cool. I do think that the factory cooler is inadequate. I added an additional cooler. I had the trans rebuilt/upgraded and it failed again at about 250k. I think the pump failed and it overheated. The pump was not changed out the first time, so it may have been an "old" condition that got it the second time. I understand That in my 2007.5 Ram, the 68rfe design was new, and not all that mature and perfected. Some say the 6.7 Cummins engine is just too powerful / torque-ey for the 68rfe, but I don't think I drove in such a style to blame it on that. Anyway, I got rid of that trans and got a built aftermarket.

The 68FRE is rated at 890 lb. ft. of torque; 920 after 2017. Transmission techs I know consider them to be "adequate" for the Cummins, but I don't think there's much margin there for abusive treatment.

Newer 68RFEs seem to be more durable than the early years. (I believe there was a thrust washer retrofit prior to 2016.)

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build Date: 3 June 2018. Now at 93319 miles.

 

[FlatbedHemi]

I think your odds of a successful service life w this trans is keeping trans temps at bay. I have 195K on mine and have never had any issues. I did install an aftermarket trans cooler with fan (in addition to the factory cooler). Whenever my truck is on the road it is always loaded to about 11K lbs gross (it’s a Ram2500), but will often be hauling close to 18K gross for shorter distances. I drive it easy, but given its history so far I expect that trans to last as long as I have the truck. One other issues this trans was a clunking sound when I put it in gear. I figured that out and the hard clunk went Away. I figured out where this trans likes the fluid level to be on the stick…hence, I also installed a drain plug in my pan so I could tweak the level of fluid just perfecrly

So what ended up being the cause of the clunk? Mine does that going in and out of park.

 

[FlatbedHemi]

Since starting all of this I have been paying more attention to the “gauge” readout on my cluster display. I usually just leave it on the fuel mileage screen, but have kept it on the screen with the 3 temp readings and the oil pressure. I guess so far Im lucky that my thermo Is still working. Been towing and driving unloaded, in 98+ degree weather and she’s reading 168 almost completely consistently. Let’s hope it stays working until the bypass gets here and I have time to install it.

Really just hoping she’ll stay in good shape until after August. Gotta make a cow run to south Texas and definitely don’t want a failure on that trip. Cross your fingers and toes, knock on wood, and wish me luck.

 

[FlatbedHemi]

My 68RFE died at about 190k miles. I do some towing, but not a lot. I tow a dump trailer at 10k pounds locally-short distances maybe 10 times a year. 7k travel trailer maybe 2000 miles a year. ordinary driving habits, nothing high power or extreme. I took great care of it and kept it well fed and relatively cool. I do think that the factory cooler is inadequate. I added an additional cooler. I had the trans rebuilt/upgraded and it failed again at about 250k. I think the pump failed and it overheated. The pump was not changed out the first time, so it may have been an "old" condition that got it the second time. I understand That in my 2007.5 Ram, the 68rfe design was new, and not all that mature and perfected. Some say the 6.7 Cummins engine is just too powerful / torque-ey for the 68rfe, but I don't think I drove in such a style to blame it on that. Anyway, I got rid of that trans and got a built aftermarket.

Did you have a local shop do your rebuild or buy one online?

 

[Omegasupreme]

I am at 150k right now and it's acting up. I get jolting downshifts, almost like trailer brakes locking up.
I would not trust the temps on your display at all. There was a video by watch wes work, where he was working on a ram. The temps were artificial on the gauges and we're not accurate.

 

[Omegasupreme]

Here it is.

When Live Data Lies - 2015 Ram 3500 Thermostat Diagnosis and Replacement - P0128, P2181

Diagnosing a bad thermostat is not difficult. But when computers are programmed to lie, it makes it a little more tricky. Especially when the computer also c...

youtu.be

 

[mtofell]

I am at 150k right now and it's acting up. I get jolting downshifts, almost like trailer brakes locking up.

That sounds like pretty classic valve body stuff. Mine did that for a (short) while before failing.

 

[RiverRatJim]

My wife’s uncle just bouth a 3rg gen cummins and not a month later the transmission pooped out on him. Truck had around 150k. They took it to a reputable repair shop and they said nothing good about that trans. They also said “They ALL”, meaning any Dodge transmission, go out around 150-180k, “if you work them”.

My truck has the 6.4 and the 66rfe, running 35” tires, steel utility/hay spear flatbed, with about 125k on the clock, that is my work horse on the weekends, and I started getting concerned. So, I got online and started doing research. I have seen more than a few posts about the 66rfe and its problems. However, I also got to wonder if having the truck regeared would help save the transmission. My truck has been running 4.88s since 75k miles, which is about when I started really working it. So, while I’m sitting here wondering how much life my transmission has left in it, I saw where someone posted and pointed out that you only see the problems when you search online, so you never know how many are out there running problem free.

So that got me to thinking, how many 66rfes are there running high miles problem free?

How many people have had problems even though they modified their drivetrain?

How many miles was on it when the trans died?

 

[RiverRatJim]

I have a 2016 3500 Laramie.
At 65k lost right front axel
At 80k truck went into limp mode, the solenoid pack went bad. I ordered a new one installed and all was great.
At 96k transmission stopped working, felt like it was stuck in 6th gear no reverse. Took it to 2 transmission shops both stated that 66rfe's on the heavy duties were bad. Got prices from both shops both were 8k range. Left it at the last shop just because they had 3 other gen 4 rams with the same issues.

 

[06 Dodge]

I have a 2016 3500 Laramie.
At 65k lost right front axel
At 80k truck went into limp mode, the solenoid pack went bad. I ordered a new one installed and all was great.
At 96k transmission stopped working, felt like it was stuck in 6th gear no reverse. Took it to 2 transmission shops both stated that 66rfe's on the heavy duties were bad. Got prices from both shops both were 8k range. Left it at the last shop just because they had 3 other gen 4 rams with the same issues.

And how many of the 3 had power tuners on them? I was recently in central WA and heard several Ram owners complain how bad Ram transmission are in diesel trucks, well after asking questions I found out all of them had been reprogramed for more power, I told them the Ram trans were made to only handle X amount of TQ/HP and they all said it should of held up because so and so Ford & GMC held up to more power then what they were adding to the Cummins

 

[EastWestHemi]

I swapped out the transmission thermostat on my truck for about 6 months and the truck could barely get the fluid temps over 140. When I did the swap over i saw significant break in material drain back out of the cooler, my thoughts are there is an accumulation of metals in the front cooling system that get trapped by the thermostat. I’m considering taking the thermostat out again when I do the pan drop and filter change here in the next month.

I wonder how many of these failing 66rfe transmissions didn’t get the proper service and were overloaded? Also modified for 30-50 more hp? A ram 2500 and 3500 frames, axles, body and brakes are way more capable than a 66rfe/hemi 6.4 combo can handle considering it is the same truck that they throw a Cummins into. I’ve been towing daily with mine 5k lb work trailer, and have probably moved 300 yards of gravel over the course of the past year. I try to keep the gravel hauling to 13-15k lbs— I always tell the loader operators one less yard than I actually want because they always drop extra. Towing 15k lbs and redlining it up hills to maintain 40 mph is sketchy, at that weight I de-fuel and gently kick down into 1st and creep at 15 mph at 2000 rpm, but I’m in a rural area where I don’t have to worry about traffic. The transmission just isn’t engineered to tow 15,500 lbs like a ***** ape.

About 10k miles ago I was starting to get some transmission harshness, dropped the 6-7 quarts in the pan and replaced with redline C+. Things smoothed back out in 1000 miles.
Who knows, maybe it’s a roll of the dice whether you get a good one or bad one? I also never buy the first or last model years of a truck— rather not have them do factory problem solving during construction of my truck.

the transmission is far from perfect, we all know that, but there are a more going strong out there than failing for sure.

 

[HEMIMANN]

I swapped out the transmission thermostat on my truck for about 6 months and the truck could barely get the fluid temps over 140. When I did the swap over i saw significant break in material drain back out of the cooler, my thoughts are there is an accumulation of metals in the front cooling system that get trapped by the thermostat. I’m considering taking the thermostat out again when I do the pan drop and filter change here in the next month.

I wonder how many of these failing 66rfe transmissions didn’t get the proper service and were overloaded? Also modified for 30-50 more hp? A ram 2500 and 3500 frames, axles, body and brakes are way more capable than a 66rfe/hemi 6.4 combo can handle considering it is the same truck that they throw a Cummins into. I’ve been towing daily with mine 5k lb work trailer, and have probably moved 300 yards of gravel over the course of the past year. I try to keep the gravel hauling to 13-15k lbs— I always tell the loader operators one less yard than I actually want because they always drop extra. Towing 15k lbs and redlining it up hills to maintain 40 mph is sketchy, at that weight I de-fuel and gently kick down into 1st and creep at 15 mph at 2000 rpm, but I’m in a rural area where I don’t have to worry about traffic. The transmission just isn’t engineered to tow 15,500 lbs like a ***** ape.

About 10k miles ago I was starting to get some transmission harshness, dropped the 6-7 quarts in the pan and replaced with redline C+. Things smoothed back out in 1000 miles.
Who knows, maybe it’s a roll of the dice whether you get a good one or bad one? I also never buy the first or last model years of a truck— rather not have them do factory problem solving during construction of my truck.

the transmission is far from perfect, we all know that, but there are a more going strong out there than failing for sure.

Thanks for sharing. How many miles are on your truck?

 

[EastWestHemi]

52k right now, it was babied for the first 20k and been going hard for 32k

 

[EastWestHemi]

As important as maintenance, etc. is, there is a certain amount of luck with these (or any) trannys. For all of you that have installed things to keep it cool and/or are changing the fluid and tight intervals, mine crapped at 38K under zero load with VERY few towing miles. It crapped again at 90K under similar usage patterns. I guess my point is just because these trannys are treated well doesn't mean they won't fail.

Sure, maintenance is important but I wouldn't count on that entirely to manage the risk of things going wrong. I'm sure my experience is not typical but I'd personally sell my truck rather than own it without a warranty. I'm at 130K and have been through two trannys and an engine.

I’ve read through your 66rfe experience now for a couple years. That is poor luck! Do you or the dealer have any theories on why your truck keeps eating the power train? When your engine went was it the lifters eating the cam? What do they say about the tranny? Are the dealers just throwing parts at the thing? You must be really frustrated. I depend on my truck too much to have one that grenades every 30-40k miles— if I had a bad one it would be gone. What about your engine and transmission mounts? Have they been replaced also?

The OCI in my opinion takes the truck too many miles. 7000-8000 miles on a truck that gets 8-11 MPG city driving is a lot of fuel— most four bangers that get 25-35 MPG get the same OCI.

I currently have 15w40 Mobil delvac in for the summer— dual CK-4/ SN rated, engine really likes it. I have found the thicker oil is better with this engine. The Pennzoil 0w40 is thin to start and doesn’t get magically thicker after 7500 miles.

 

[mtofell]

I’ve read through your 66rfe experience now for a couple years. That is poor luck! Do you or the dealer have any theories on why your truck keeps eating the power train? When your engine went was it the lifters eating the cam? What do they say about the tranny? Are the dealers just throwing parts at the thing? You must be really frustrated. I depend on my truck too much to have one that grenades every 30-40k miles— if I had a bad one it would be gone. What about your engine and transmission mounts? Have they been replaced also?

The OCI in my opinion takes the truck too many miles. 7000-8000 miles on a truck that gets 8-11 MPG city driving is a lot of fuel— most four bangers that get 25-35 MPG get the same OCI.

I currently have 15w40 Mobil delvac in for the summer— dual CK-4/ SN rated, engine really likes it. I have found the thicker oil is better with this engine. The Pennzoil 0w40 is thin to start and doesn’t get magically thicker after 7500 miles.

Yeah, it's funny, as frustrated as I could be, I'm just thankful that I have the Lifetime Warranty. Also, I only live where my truck is about 1/4 of the time and had another company vehicle to drive when it sat at the dealer for the engine repair so the whole thing was only minimally inconvenient. Mainly, I just missed driving my truck.

I suppose I just chalk it up to bad luck but two trannies and an engine by 110K is statistically pretty amazing. And it's not like I drive it hard or crazy. No mods, not much towing, etc. The dealer doesn't really have any ideas but they just keep fixing it. Needless to say I'm on a first name basis with the entire service staff

With the engine failure I don't think it was cam/lifter related. I just got a misfire code with some knocking and they said they found metal shavings somewhere that indicated some bearing deep in the engine had failed and shot metal everywhere. The service manager said in ten years there he'd only seen that happen a handful of times. Again, I guess it's just bad luck. I just put about 2500 miles on in a week road trip from Oregon down to Vegas and back and the truck did great. Needless to say I was glad when I got back that I didn't break down along the way. Aside from the engine and tranny the truck has been pretty reliable. As in, it hasn't had a lot of nagging issues... just big things. I suppose that's a bit like the old saying, "Other than that, how was the play, Mrs. Lincoln."

 

[EastWestHemi]

Yeah, it's funny, as frustrated as I could be, I'm just thankful that I have the Lifetime Warranty. Also, I only live where my truck is about 1/4 of the time and had another company vehicle to drive when it sat at the dealer for the engine repair so the whole thing was only minimally inconvenient. Mainly, I just missed driving my truck.

I suppose I just chalk it up to bad luck but two trannies and an engine by 110K is statistically pretty amazing. And it's not like I drive it hard or crazy. No mods, not much towing, etc. The dealer doesn't really have any ideas but they just keep fixing it. Needless to say I'm on a first name basis with the entire service staff

With the engine failure I don't think it was cam/lifter related. I just got a misfire code with some knocking and they said they found metal shavings somewhere that indicated some bearing deep in the engine had failed and shot metal everywhere. The service manager said in ten years there he'd only seen that happen a handful of times. Again, I guess it's just bad luck. I just put about 2500 miles on in a week road trip from Oregon down to Vegas and back and the truck did great. Needless to say I was glad when I got back that I didn't break down along the way. Aside from the engine and tranny the truck has been pretty reliable. As in, it hasn't had a lot of nagging issues... just big things. I suppose that's a bit like the old saying, "Other than that, how was the play, Mrs. Lincoln."

If you have the lifetime warranty then I assume you have a 2014?

Mine is a 2016, no lifetime warranty option when I purchased

 

[mtofell]

If you have the lifetime warranty then I assume you have a 2014?

Mine is a 2016, no lifetime warranty option when I purchased

Correct.... the best $2300 I ever spent. And, actually, I only spent $1150 as I had a business partner at the time so he paid half The way truck values are I don't that the day will ever come that a repair exceeds the value of the truck (and then the warranty is done). At last check even at 9+ years old and 130K the truck books out at well over 20K.