66 rfe swap?

I’ve got a 2017 Dodge Ram 3500 Reg cab dually 4x4 with 4.10 rearend. I hotshot for a livin, so I do a **** ton of driving. Currently truck has 240k and runnin like a top. At 93k engine went due to lifter lock up on cylinder #8, sent metal shavings through the whole engine, so got a brand new long block dropped in courtesy of Chrystler.

Other then that, no issues At all. Stock tranny. Stock rearend. Stock front end. Just routine wear items.

But eventually, I know this tranny will fail. Last year I did 107k miles. And although these HDs are badass, they are not semis. 90-100k a year every year with every single mile hooked to a gooseneck takes it toll. I do religious maintenance. Tranny flushes with fluid changes and filter changes, diff fluid changes (front and rear) , oil changes and oil analysed, ect ect ect. My question is, when this tranny goes, could I go back with an AS66RC (Aisin) tranny instead of another 66RFE?

I know they offer them in C&C trucks, mines a regular 3500 pickup that I’ve pulled the bed and stripped down to C&C style. Just curious. If the Aisin swap is not possible, I’ll be going back with a factory OEM 66RFE. I’ve got buddies that have trannies go and they always go “built/aftermarket” ****. I’ve seen them deal with more failures with that then I care to mess with. I mean, I’m not a smart man, but I know OEM can handle 240k of abuse, idk what some “aftermarket” **** can do lol.

But just curious if anyone has done this/ has knowledge of if it’s possible.

Sorry, no info on the Aisin but I would call up Firepunk diesel since you are in Ohio. The 66 shares a lot of parts with the 68rfe that is behind the cummins. You can put stock back in these but they have inherent problems that the factory doesn't address. The biggest thing is the crossleakage in the valve body. Personally I am going to a billet channel plate and a few other VB updates and leave it.

Get ready for the 8 speed swap posts...bullet proof the 66 and be done with it.

If you can get the as66rc from a C&C, I go that route. it is a stronger transmission with a lower first gear than the 66rfe. There is nothing too wrong w the 66rfe except the 1-2 gear step

I have no personal knowledge on an aisin swap. I would think it would bolt in no problem, as you noted the c/c comes with the aisin. The difficult part would be the electronics and TCM place and what would be involved to get them to play nice with your existing equipment.

I'm confident it could be done, but would the expense of changing wire harnesses, modules, programming, etc be cost effect versus having a 66 built to address some of the inherent issues? That's the question. I have heard of valve body issues also and it makes me consider having that upgrade done before I have issues.

Its tough on a 240k mile gas powered truck what is the best course of action. Good luck with your decision and since you depend on your truck to make a living, good call researching this now ahead of a failure.

I think if I was a hotshotter for a living, I'd have to have a spare rig just in case I had a failure so I could keep food on the table if an issue arose.

I've been looking into swapping my 66RFE .. the Aisin as66rc is very expensive from my findings so I'm currently looking at a G56 swap. Still waiting on response from the tranny place my truck is at. There is a lot of aftermarket for the 66RFE and I have most of those parts in my 66 but it still failed. I no longer will think of the 66RFE as a truck tranny as it came from the light duty 1500 and muscle cars, the clutch pak in this tranny is way to small to handle the power or weight. I like the design of the RFE and it has always got me home after each failure ... I've just had enough and not on warranty anymore so time for a change

BlackGold6.4 said:

I've been looking into swapping my 66RFE .. the Aisin as66rc is very expensive from my findings so I'm currently looking at a G56 swap. Still waiting on response from the tranny place my truck is at. There is a lot of aftermarket for the 66RFE and I have most of those parts in my 66 but it still failed. I no longer will think of the 66RFE as a truck tranny as it came from the light duty 1500 and muscle cars, the clutch pak in this tranny is way to small to handle the power or weight. I like the design of the RFE and it has always got me home after each failure ... I've just had enough and not on warranty anymore so time for a change

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Please let me know about that G56 swap. That’s my first choice honestly. Living in Ohio with the hills, and Runnin the north e East allot always towing a standard would be ideal. I’ve wondered about the G56 swap, my main concern is how would u reflash the PCM from a automatic to a standard. Obviously if they do the swap for you, you’ll get all that info. Please let me know what shop is doing it, and their contact info so I can pick their brain. And lemme know how itgoes!

@Pktatum95 yes for sure I will .. I'm in Canada but there is a dude in Texas that does amazing work with these swaps.. still trying to find his online info. My truck is at Bob's transmission in Winnipeg MB and he has rebuilt my 66RFE. I love what he did to my 66 but we think it failed due to the cold weather up where I live above the 55th parallel .. still looking into it.

http://lazarsmith.com/Transmission.html @Pktatum95 check this out, wish I could afford to get my tranny swapped by this guy.

I am going to be getting a G56 in my truck.. Wanted 4.88 gears but may have to settle for 4.56, apparently the front 9.25 diff is not strong enough to handle the gears. After doing some research there is a brace for the front diff that has to be welded on... $$$

Hey everyone interested in swapping out a 66RFE.. It can be done with truck from before 2014 but not after 2014 .. so yes that means I will not be getting a G56 .. I'm so depressed.. Due to the PCM that communicates with modules in the transmission, transfer case and diffs the truck would end up with the engine light on all the time. The engine will lose power because of this and lots of other drivetrain issues will occur. I will keep you's post as to my next step but right now I just want to go home and have a stiff drink..

The Aisin doesnt have the same rep as the older Allisons is the talk around the block. If you ae going with stock Aisin, I don't know that it would be better then a built rfe. The one thing about the rfe they are very buildable... With those miles you will want a new rfe, but you can see what happens to these below vid, look up sun coast diesel good info...

There are a lot of 68RFE aftermarket parts out there that address a lot of the shortcomings of the RFE trans. The 66RFE is virtually the same as the 68RFE so you could always beef up the 66 to be better than stock. If it were me I would look into that instead of the Aisin. As mentioned they aren't cheap and have their own flaws.

just throwing this out there, I really think the RFE trans in general gets a bad reputation from all the people out there in Cummins trucks that run 350hp tunes on their trucks. They blow the trans apart and then cry about how "bad" the trans is. The fact that you have that many miles on a stock 66RFE towing as much is exactly what I'm getting at.

Over 200k, why would he want something different?

Burla said:

The Aisin doesnt have the same rep as the older Allisons is the talk around the block. If you ae going with stock Aisin, I don't know that it would be better then a built rfe. The one thing about the rfe they are very buildable... With those miles you will want a new rfe, but you can see what happens to these below vid, look up sun coast diesel good info...

Product Overview: ATS 68RFE Valve Body and ATS Co-Pilot

Clint Cannon, President of ATS, describes the inherent weaknesses of the 68RFE (545RFE, too) valve body. This is a comprehensive overview of the numerous pro...

youtu.be

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Both Rock Auto and Summit Racing are still out of Sonnax Upgraded RFE Valve Bodies. I'm thinking it's due to lack of valve body cores to rebuild, but that's an educated speculation.

Would be cool if a 68RFE fit behind a Hemi but we have a smaller clutch pack in the 66RFE given it's weak point. Heat is a major issue with these trannies.. and the fact that the 66RFE came from sports cars and 1500's make me wonder why is it in a HD truck.

BlackGold6.4 said:

Would be cool if a 68RFE fit behind a Hemi but we have a smaller clutch pack in the 66RFE given it's weak point. Heat is a major issue with these trannies.. and the fact that the 66RFE came from sports cars and 1500's make me wonder why is it in a HD truck.

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Because it's cheap to use the same transmission. It is borderline, so ok except for tuners.

You get rid of the heat by getting rid of the oil cooler thermostat. Guys who do this and don't tune for higher power don't have issues, in general.

What sports cars did the RFE go in. It's always been a truck trans.

bigdodge said:

What sports cars did the RFE go in. It's always been a truck trans.

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All Hemi cars after a certain year .. (08 I think) had them .. parts are interchangeable between the 45 all the way up to 68RFE with 68 being the biggest

Pktatum95 said:

Please let me know about that G56 swap. That’s my first choice honestly. Living in Ohio with the hills, and Runnin the north e East allot always towing a standard would be ideal. I’ve wondered about the G56 swap, my main concern is how would u reflash the PCM from a automatic to a standard. Obviously if they do the swap for you, you’ll get all that info. Please let me know what shop is doing it, and their contact info so I can pick their brain. And lemme know how itgoes!

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A G56 can not swap into a Ram HD after 2014.. it will bolt in but will not work due to the PCM and modules it communicates with. So without the tranny module the engine will de-rate and drivetrain will not function rite.

W5a580 was the trans for the rear wheel drive cars. RFE was for trucks and SUV. Not going to fun up this thread anymore. I was just genuinely curious.

As for the 66 I think it does get a bad reputation because of the 68. Also people have no idea what is wrong when they take it to a shop and they are told it needs rebuilt. I just had new tires put on and get in to drive away and it's in limp mode. Called for a bad rear sensor. 0721 fault. Long story short it turned or to be a problem with the computer. Had I taken it to a shop I guarantee it would need a full rebuild.

You are right .. looked it up.. The operation of the RFE's is awesome and all the times it failed it still got us home but if one compares the clutches in size to all other similar trannies you'd see the weak point of it.. so add a bit of heat and this tranny will pack it in sooner then most. The 68 from my point of view stands up better than the 66 but my numbers are based locally from just talking to my dealer.
The dealers had to learn a lot about diagnosing the RFE .. twice they told me that I can drive it until the parts come and find out it needs replacing or rebuilt after.
When I had the truck the first 2 years I remember going in for programming issues with shifting and it took a bit to figure that out.