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If a new 1500 truck offered an auto trans option, which would you choose?

  • 65RFE automatic (as standard)

    Votes: 3 4.8%
  • 66RFE automatic (if it was a $250 option)

    Votes: 60 95.2%

66RFE vs 65RFE Trans

42K views 58 replies 20 participants last post by  TransEngineer 
#1 ·
2500 (DJ) model trucks now (2012 MY) use the 66RFE automatic transmission, which has different ratios than the 65RFE (which is currently used in 1500 models).

How many of you would prefer the 66RFE over the current 65RFE (for the 1500 models)? Here are the ratios:

65RFE:
1st = 3.000
2nd = 1.667
2nd prime = 1.500
3rd = 1.000
4th = 0.750
5th = 0.667
Reverse = -3.000

66RFE:
1st = 3.231
2nd = 1.837
3rd = 1.410
4th = 1.000
5th = 0.816
6th = 0.625
Reverse = -4.444

The geartrain in the 66RFE costs significantly more than that in the 65RFE (it is much more durable), so a 66RFE trans would probably cost more (maybe $250, but that's just a wild guess). But given the option (65RFE as standard, or 66RFE as a $250 option), which would you choose?
 
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#3 ·
Hi TransEngineer,

For a more durable transmission, I'm sure I'd spend the extra money and get the 66RFE if it were an option. I'm guessing the higher ratio on the 2nd overdrive would provide a little extra fuel economy at times too.

Would the 66RFE upshift and downshift through all 6 gears in normal driving?

Bill
 
#4 ·
Definitely the 66RFE. The lower ratios in the low gears would help get this heavy truck up and going much better.

Any thoughts on making this available as a "dealer swap" for our 2011 RAMs with full warranty conditions??? I would be in for that. :smileup:
 
#5 ·
Any thoughts on making this available as a "dealer swap" for our 2011 RAMs with full warranty conditions??? I would be in for that.
Or 2010's ??? :) I'd even be willing to pay (a fair price) to make that trans work with my truck. I plan on keeping this truck a long time, I love it, so it would not be a bad investment.
 
#6 ·
Yes, the 66RFE does shift through all 6 gears in normal driving.

Swapping in a 66RFE (in a 2010-2011 truck) would require new PCM software to enable the correct shift pattern. And that creates a concern for keeping the software and hardware matched. Suppose you installed a 66RFE (with new PCM software). A year later, you go to your dealer for an oil change, and he "helpfully" updates your PCM to the latest level of software (for a 545RFE truck!!). So there are some issues with doing this.... but I'll see if any of my colleagues think it might be a possibility.
 
#25 ·
If your dealer installs the transmission it goes in your service file and will be added to your vehicle serial#... so I was told by my dealer back in 2011. In my case with an 09 it would void my lifetime warranty but who cares. The problem is the tcm is in the pcm...it is not a stand alone control like the 68RFE. So we have to figure a way to swap our pcm to a 2012 HD 2500 Hemi of the same model. The 545RFE/65RFE has a hp sucking gear ratio, it's garbage. The 66RFE are spread even and better appart and it's much stronger. Hell yeah I'd go for one in a heart beat! I've never checked but we need to find out if the harness is simular between either of the three. Possibly we may be able to use the 65RFE harness....just a thought....or hopefully even the 545. Then all we have to do is tune it respectively to accept the shift schedule (that would be on a wing and a prayer). Or worse case senerial swap out the pcm to the correct one.
 
#7 ·
Swapping in a 66RFE (in a 2010-2011 truck) would require new PCM software to enable the correct shift pattern. And that creates a concern for keeping the software and hardware matched. Suppose you installed a 66RFE (with new PCM software). A year later, you go to your dealer for an oil change, and he "helpfully" updates your PCM to the latest level of software (for a 545RFE truck!!). So there are some issues with doing this.... but I'll see if any of my colleagues think it might be a possibility.
Thanks for the info and looking into it.
 
#8 ·
I would certainly hope that our Dealers would be fully aware of which tranny is in which 1500... Maybe a Big Yellow Sticker under the hood just for the less than sharp Service Techs. :i_rolleyes:

I would hope we wouldn't have to rely on the competency of a given Tech vs the incompetency of said Tech in you guys making this decision...

Thanks for even giving this idea some legs...
 
#10 ·
Having thought some more about this (releasing a 66RFE trans with revised PCM software for 2011 and earlier trucks), I now realize it ain't gonna happen.

Obstacle #1 is the fact that (since the PCM software controls both engine and trans) there are myriad combinations and permutations of PCM software, depending on model year, engine, emissions package, fuel tank size, etc. So we would need to create MANY new sets of PCM software, not just one-size-fits-all.

Obstacle #2 is that anything we market would have to be certified as meeting emissions requirements. This is the big problem! There is no way we have the resources to go back and re-certify all the different combinations, with a 6-speed transmission with different ratios and a different shift schedule, especially figuring these would be low-volume sales.

So I'm sorry, but there is no chance (that I can see) of this actually being feasible for us to do. Maybe someone in the aftermarket could work up a package for this retrofit.

I should also note that 66RFE transmissions use an extension (or 4x4 adapter) that are not compatible with 1500 models. So those would have to be swapped out (which can be done, the parts will interchange). But changing the extension/adapter may also change the rear geartrain end play, and if the end play winds up out of spec, it would be necessary to tear the trans down and change a selective spacer to adjust it.

I should also note that the solenoid module used in the 2012 (66RFE) transmissions is NOT backwards-compatible with 2010 and earlier model years, so you'd also have to swap out the solenoid pack.

Also, the torque converter now being used with the 66RFE is different from that used in 2011 and prior years. This is not a big deal (the new one would probably work fine), but for anyone trying to keep emissions legal (not likely a huge concern for anyone undertaking this!), the new converter could change the emissions performance.

So I guess things are never as simple as they seem at first. Sorry.....
 
#26 ·
I should also note that 66RFE transmissions use an extension (or 4x4 adapter) that are not compatible with 1500 models. So those would have to be swapped out (which can be done, the parts will interchange). But changing the extension/adapter may also change the rear geartrain end play, and if the end play winds up out of spec, it would be necessary to tear the trans down and change a selective spacer to adjust it.

I should also note that the solenoid module used in the 2012 (66RFE) transmissions is NOT backwards-compatible with 2010 and earlier model years, so you'd also have to swap out the solenoid pack.

Also, the torque converter now being used with the 66RFE is different from that used in 2011 and prior years. This is not a big deal (the new one would probably work fine), but for anyone trying to keep emissions legal (not likely a huge concern for anyone undertaking this!), the new converter could change the emissions performance.

So I guess things are never as simple as they seem at first. Sorry.....
I saw these transmissions side by side a while back. The converters are interchangable and the housing is exactly the same. Don't know about the 4x4 but my 2x2 is the same. I didn't get to see the harness or any wiring though. As far as emissions I don't see what that has to do with it but I repspect your findings. I don't think anyone would care about that if they plan on using a stall speed converter down the road anyway. Say in my case, (2009 RCSB Hemi ST) why can't I swap out the entire engine control system (pcm/tcm, it's all in one housing) from a 2012 HD 2500 Hemi ST....the same model except it would be RCLB? I even thought of taking the pcm appart and sperating the tcm. The 68rfe is supposed to be two separate units but it's been a while so I may be wrong. Plz don't give up looking into thisd....you started this now you have to finish. You are the first person I saw that has had any interest in rthis and you're a trans tech...help us! :Hey:
 
#11 ·
^ I was expected a response similar to that lol. Thanks for the input, it's nice to know that someone who has the know how at least makes an effort :)

Like you said, maybe the aftermarket could provide this, although it's probably unlikely. It sounds like it'd be a lot of work. I know a couple guys at superchips, maybe I'll talk to them and see if they'd consider a program for something like this, where if the customer swapped the mechanical parts, they could sell the pcm programming to match. Doubtful that it'll happen, especially through them as they are oriented to plug and play on stock vehicles.

Technology is great, but it sucks when you can do the mechanical aspect yourself, and then are stuck in limbo with the electrical/software part...
 
#15 ·
Well that'd still give the same ratios though....the 66rfe would be (I think) a "faster" transmission and also more mpg efficient.

IMO the main benefit is the better 1st gear, the evenly spread mid gears, and the better final gear. The "stronger" aspect of it is a bonus, because IMO the 545rfe/65rfe is strong enough for 95% + of us.
 
#16 ·
Please let the 66rfe be the new trans for the 2013's!!!! Now that I know the 8 speed is not happening for 2013, I would still be willing to buy a Ram with a true 6 speed. I'm keeping my fingers crossed that this is the case when they release the details for the 2013's. I just hope I can hold off buying a truck until then. The Sierra's 21 hwy mpg is looking pretty appealing right now.
 
#17 ·
Or just get a 2500 for about $1000 more and get all the other great upgrades :D
 
#19 · (Edited)
I don't see that in our future, going back to stick shift transmissions

I even see the change to more of the Allison type Transmissions replacing standard sticks in the Heavy Duty Rams, seems to be the way things are going

But that is just this old farts opinion

I miss the days of the Eaton Fuller & Road Ranger transmissions, 10, 13, & 15 speed stick transmissions, i retired 7 years ago, now i drive a Automatic Ram & a Harley 4 speed
 
#20 ·
66rfe and '12 vin 'T' 5.7l PCM?

Hey transengineer,

Would a 66RFE play nice with a PCM on a 2012 1500 5.7l? I am looking into a engine/tranny swap for my 2006 Mega Cab, because I want add the MDS and vvt. So, I am wondering if the move to a 66RFE would be possible, or would i run into the same pre-'12 PCM issue you mentioned above.
 
#21 ·
Hey transengineer,

Would a 66RFE play nice with a PCM on a 2012 1500 5.7l? I am looking into a engine/tranny swap for my 2006 Mega Cab, because I want add the MDS and vvt. So, I am wondering if the move to a 66RFE would be possible, or would i run into the same pre-'12 PCM issue you mentioned above.
While the solenoid module would not need to be changed, the other considerations still hold true. I'm not sure offhand whether the converter would be identical or not (probably is, but I'm not sure).

But the biggest issue would be the PCM. The gear ratios for the 66RFE are different from the 65RFE, so if you just hook it up as is, you will blow gear ratio error faults immediately (and continually). It would be unusable for that reason. And I don't know of any way to get the PCM reprogrammed to the new ratios.
 
#24 ·
Bringing this thread back up.... I'm looking into this very thing right now. First step it to see if the harness is the same. Second is converter mounting and 3rd controlling it. Since arrington can flash with OEM software now I don't think this is too far fetched.
Gonna try and locate a 66rfe now
 
#27 ·
I've been looking off and on now for over a year. Like trans tec said they about 250 bucks more then a 545 and sell for 3700 if I'm remembering correctly. There are plenty of performance trans shops that have their own stand alone tcm units that may be able to tune these things. It ticks me off, FAST has had one for the Chevy units for some time but not for Chrysler. But there are others I saw, just have to search again. I'll put a stock one in mine right now, I'm ready...my truck is stock.
 
#28 ·
Yes, your best bet (in my partially uninformed opinion) would be to use a PCM from a 2500 5.7L truck (66RFE trans). At least that way, the trans controls would work correctly. But I'm not sure if the engine controls / emissions are similar enough (between 1500 and 2500) that the engine side of the 2500 PCM would work correctly in a 1500.

Biggest difference is that the 2500 does not have MDS (while the 1500 does). I compared the wiring connector pinouts for the NGC4A PCMs for 2012 MY 5.7L trucks (1500 with 65RFE versus 2500 with 66RFE). All of the connector pinouts are IDENTICAL, except the 2500 has "no connection" at the four (4) circuits that are used for the MDS solenoids in the 1500. Therefore, I suspect (but cannot guarantee!!) that using a 2500 PCM in a 1500 would work fine, except MDS would be disabled.

The MDS solenoids are controlled on the high (supply) side, so having no connection to the solenoid (from the PCM) should simply disable MDS. Normally, this would blow a host of faults (for cylinder deactivation performance, MDS solenoid circuit, etc.) but since you'd be using the 2500 PCM those faults should be deactivated (since the 2500 does not have MDS).

The big issue in my mind is that the VIN in the 2500 PCM will not match the one in your 1500. I don't know how all the module-level security works, but I suspect this could be a problem. Check with a knowledgeable dealer tech and ask them whether you could successfully install a 2500 PCM (new or used) into a 1500 truck.

On the trans hardware end, all the wiring and connections are the same. The 2WD extension IS different (the 2500 uses a larger diameter slip yoke), so you'll have to either swap in the old extension from your 65RFE (which should work) or change the propshaft slip yoke (which may be more of a challenge). The torque converter should actually be identical between a 5.7L 1500 (65RFE) and a 5.7L 2500 (66RFE), so that won't be a problem.

Good luck, and let us know if it all works out!
 
#31 ·
I don't see why Arrington, B&G, or Diablo couldn't flash a 2012 Hemi HD PCM with our VIN from our 1500 Hemi or force flash the 66rfe trans control file to our 1500 PCM. I have no problem losing MDS, turned it off every time I loaded a tune anyways.

Josh, are you working on this project in Orlando? Or in Cocoa? I'd love a 66rfe in my truck, but suspect it'd be even MORE difficult getting the programming to work in the 4.7L than the hemi.
I'm not sure if it would work with a 4.7. You probably wouldn't be able to use a Superchips do the custom tune necessary for the transmission/engine combo. Most likely will have to send your PCM to one of the above for the custom PCM flash.

Josh get it done! Then when I blew up my next 545 we can swap mine with ease.
 
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