swap my 66RFE for a G56....cost?

[ScubaSteve178]

To slow to handle but all that is left is realign transfer case and fit a new driveshaft. My builder is confident that a HP tuner will fix the codes, he's been on touch with a HP rep about it. I went through a lot of details with my builder to get to this point so yes where almost there

Any updates on this? Been following for awhile as my transmission slowly shows more and more signs of failure. lol

 

[BlackGold6.4]

I'm on holidays for two weeks then I go pick up my truck.. I will update on everything then.

 

[ScubaSteve178]

I'm on holidays for two weeks then I go pick up my truck.. I will update on everything then.

Sounds good- enjoy the time off, I look forward to the results!

 

[392DevilDog]

I'm on holidays for two weeks then I go pick up my truck.. I will update on everything then.

Awesome! Can not wait for the report. Hope your doing well and having a great time

 

[ScubaSteve178]

Any luck BlackGold6.4? Hoping all is well.

 

[BlackGold6.4]

Any luck BlackGold6.4? Hoping all is well.

Delayed another month.. came back from holidays and had to find a ride home 8 hr drive north of Winnipeg. Not a happy camper.

 

[BlackGold6.4]

Thanks for thinking of me @ScubaSteve178 .. as soon I'm driving home with my truck I will be posting all about it.
How the engine works with the manual,
How the HP tuner works with the pairing,
How the trucks cruising speed changes,
And possible fuel mileage change

 

[ScubaSteve178]

I take it this truck is still in limbo? Any word from your builder and what snags he's run into?

 

[BlackGold6.4]

Yes we've had more snags but I can't give you any info yet, I will be going south for spring break and visit my builder and should have some sort of info after that.. my disappointment will not show so good in this communication but I'm very defeated right now and hoping that will change after "the visit". Thanks for keeping in touch @ScubaSteve178

 

[olyelr]

Ugh. Well keep us up to date when you can!

 

[Kuhndog970]

Yes we've had more snags but I can't give you any info yet, I will be going south for spring break and visit my builder and should have some sort of info after that.. my disappointment will not show so good in this communication but I'm very defeated right now and hoping that will change after "the visit". Thanks for keeping in touch @ScubaSteve178

Have they explained what the hold up is? Seems a little sketchy to me. For what I have researched and researched about this because I plan to do the swap myself, it seem that a lot of of what they have told you is off to me. Not saying they are cheating you but I'm not understanding what the t case issue is. The 6.4 trucks have the same t case as the cummins truck that came with the g56. Driveshaft lengths are different for sure but that t case in your truck would bolt straight to the g56. If its a manual t case then linkage would need modification or just throw the correct cummins linkage in it and if electric then you may need to extend the wiring but that should be the extent of that install. I could understand if the tuning is the hold up because it doesn't seem that there is a straight forward play by play on doing this, however, folks have swapped countless chargers and challengers to a manual and that goes just fine with reputable tuners. Do you mind me asking what the total cost is at for this? I feel like they are milking you as unfortunate as that is to say.

 

[Bigskyroadglide]

Here's a shop talking about this in great detail

Precision Diesel & Automotive

We Are A Complete Diesel & Automotive Repair Shop!

precisiondieselandauto.com

Precision Diesel And Auto on Instagram: "Truckers are traveling HUNDREDS of miles for our G56 swaps… #truckdriver #dieselmechanic #dieselrepair #g56swap #dieseltrucks"

5,539 likes, 82 comments - precisiondieselandautomotive on May 12, 2025: "Truckers are traveling HUNDREDS of miles for our G56 swaps… #truckdriver #dieselmechanic #dieselrepair #g56swap #dieseltrucks".

www.instagram.com

 

[catscape]

Here's a shop talking about this in great detail

Precision Diesel & Automotive

We Are A Complete Diesel & Automotive Repair Shop!

precisiondieselandauto.com

Precision Diesel And Auto on Instagram: "Truckers are traveling HUNDREDS of miles for our G56 swaps… #truckdriver #dieselmechanic #dieselrepair #g56swap #dieseltrucks"

5,539 likes, 82 comments - precisiondieselandautomotive on May 12, 2025: "Truckers are traveling HUNDREDS of miles for our G56 swaps… #truckdriver #dieselmechanic #dieselrepair #g56swap #dieseltrucks".

www.instagram.com

If I'm not mistaken, they G56 swap diesel trucks only?

My 66RFE mated to a 6.4 Hemi is starting to show signs of failure, thinking about throwing in a G56 instead of rebuilding it. This is the only thread I'm seeing so far with progress towards that goal.

@BlackGold6.4 How did the visit go? Did you figure anything out?

 

[U&A]

@catscape
What exactly are your “signs of failure” out of curiosity. Appreciate your insight.


Iv often considered the G56 swap but i seriously think takeing the steps to improve the 66RFE with aftermarket parts is a really great way to go. “Better” way maybe? Don’t get me wrong. I’d absolutely adore to have a manual transmission again.

The 66 is actually a really good trans, just needs a few things replaced to make it a really great trans.

Iv got over 101,000 miles on mine now, tow fairly often, plus it works a bit harder with the 35” heavy load range F tires on it. though i am re-geared to 4.88’s the trans still works harder than originally. I also have been doing fluid filter changes every 20,000 - 30,000 miles. And as goofy and almost embarrassing as it sounds, when the transmission was newer, I actually did fluid filter changes more frequently than that.

I will NOT be surprised when it needs a re-build in the next 50,000 - 70,000. When that time comes im definitely re-building and doing my best to “bulletproof” the 66RFE (i hate that term but you know what I mean)

 

[HEMIMANN]

@catscape
What exactly are your “signs of failure” out of curiosity. Appreciate your insight.


Iv often considered the G56 swap but i seriously think takeing the steps to improve the 66RFE with aftermarket parts is a really great way to go. “Better” way maybe? Don’t get me wrong. I’d absolutely adore to have a manual transmission again.

The 66 is actually a really good trans, just needs a few things replaced to make it a really great trans.

Iv got over 101,000 miles on mine now, tow fairly often, plus it works a bit harder with the 35” heavy load range F tires on it. though i am re-geared to 4.88’s the trans still works harder than originally. I also have been doing fluid filter changes every 20,000 - 30,000 miles. And as goofy and almost embarrassing as it sounds, when the transmission was newer, I actually did fluid filter changes more frequently than that.

I will NOT be surprised when it needs a re-build in the next 50,000 - 70,000. When that time comes im definitely re-building and doing my best to “bulletproof” the 66RFE (i hate that term but you know what I mean)

What ATF you using?

 

[U&A]

What ATF you using?

Originally redline

3-4 years ago I switched to Amsoil SS multi-vehicle

And im using a Royal Purple spin on filter in the trans.

 

[HEMIMANN]

Originally redline

3-4 years ago I switched to Amsoil SS multi-vehicle

And im using a Royal Purple spin on filter in the trans.

If you don't mind my Spanish Inquisition (inquiring minds need to know, or more likely that's the purpose of a forum),
Did you notice any performance difference?
Why did you switch?
Did you try the Wix spin on filter?

I've stayed with Red Line C+ATF, trans really likes it. Smooth, concise shifts. Have no problems I know of with the Wix rock catcher spin on filter in there. Of course, I've been using the ATS steel pipe n i p p l e adapter since 1st oil change, also. And the LubeLocker pan gasket is the real deal - no more leaks, no more messy RTV gasket maker.

 

[catscape]

@catscape
What exactly are your “signs of failure” out of curiosity. Appreciate your insight.


Iv often considered the G56 swap but i seriously think takeing the steps to improve the 66RFE with aftermarket parts is a really great way to go. “Better” way maybe? Don’t get me wrong. I’d absolutely adore to have a manual transmission again.

The 66 is actually a really good trans, just needs a few things replaced to make it a really great trans.

Iv got over 101,000 miles on mine now, tow fairly often, plus it works a bit harder with the 35” heavy load range F tires on it. though i am re-geared to 4.88’s the trans still works harder than originally. I also have been doing fluid filter changes every 20,000 - 30,000 miles. And as goofy and almost embarrassing as it sounds, when the transmission was newer, I actually did fluid filter changes more frequently than that.

I will NOT be surprised when it needs a re-build in the next 50,000 - 70,000. When that time comes im definitely re-building and doing my best to “bulletproof” the 66RFE (i hate that term but you know what I mean)

A few weeks ago I was taking a break. Truck sat idle for like 20 minutes and went into limp mode when I put it back to Drive. I got it back to normal by shutting the engine off, waiting a few minutes then restarting it. Then I kept on driving and suddenly there was a very rough gear shift followed by the check engine light. I immediately pulled off the highway and read the error codes with AlfaOBD: P0871, P2704 and P2706. Had the nearest mechanic take a look, he cleared the error codes and they didn't come back, so he couldn't tell what was wrong. Still it doesn't look like a good sign.

 

[BlackGold6.4]

If I'm not mistaken, they G56 swap diesel trucks only?

My 66RFE mated to a 6.4 Hemi is starting to show signs of failure, thinking about throwing in a G56 instead of rebuilding it. This is the only thread I'm seeing so far with progress towards that goal.

@BlackGold6.4 How did the visit go? Did you figure anything out?

Sorry it has taken me so long to respond... My swap is back on progress, my builder and I had settled on a few things. To date the computer remapping is the only question remaining in the balance. Physically buying everything to fit is possible. Buy a G56 with gas bell housing from 05/06 ram 2500 parts from engine block to just before transfer case. The transfer case needs to move forward and the driveshaft lengthened. We are thinking the cables should work because mine are manual shifting but parts from a 2014-18 Diesel G56 transfer case cables may be needed. As I get more information I'll post what I learn.
My problem is I work above the 56 parallel and don't have cell service all the time so I'm not online as much but as winter closes in it'll change. All the leaves are falling off and now hunting is in full swing. I have so many excuses not to be online after hunting I'll be snowshoeing, skiing, ice fishing, ...etc
In late October we are going south to pickup a side of cow so I'll know more then.

 

[BlackGold6.4]

I think another thing to consider what is your truck used for. If it's just highway and towing I would consider just upgraded the 66RFE but if you're like me and use 4 low lots the RFE will not last no matter what upgrades you do. With that said heat is your enemy. Upgrading everything external to do with heat transfer is great preventive maintenance then when it comes time upgrade the internals