Replace 48RE w/ 68RFE?

['strokeThis_'07]

Suncoast is the best source for building a 68rfe right now. They have one holding (for now) 885hp in a quadcab/shortbox 2wd... 07 I think. However, it's still a testbed, and not yet tested as to exactly how durable these will be holding power.



Obviously not everyone wants 800+hp, but a 68 will die fairly quick behind even a mildly modded 5. 9 (or 6. 7 for that matter) where-as there are pretty well proven things one can do to a 48re to last longer, whether behind a stock 5. 9 used for towing or a 1200hp race truck.



For now, a Gear Vendors or US Gear auxilliary overdrive unit is the best and cheapest bet for additional gear splitting and an added overdrive.

 

[Vaughn MacKenzie]

I hate the gearing on my stock-o-matic for towing and even daily driving, constantly shifting back and forth between 3rd and OD in a lot of situations, either revving it or lugging it.

The gearing on the Dodge 6-speed is much better than the Allison, with the Allison you basically get a lower first gear but it also has large gaps between 4th and OD. . . doesn't do much to solve the towing issue. First OD on the 68RFE is a lot more tow friendly.

 

[HBarlow]

Yep. Either way, its probably $10k to do it and expect much more than a stock trans which won't hold more than 500 HP, less in some cases.

About double the cost of the 48RE that will hold pretty much anything you throw at it. Towing it would be great but thats a steep price to pay for the gain. Comes down to how much one is willing to spend.




I am sure at one time that was true as it was a brand new product that is a total departure from anything Dodge had done. Simply takes time for trial and error to develop the a build that will function correctly.

Fortunately, thats not true anymore but the knowledge is held by a few and still in development.

The Ally is a perfect example, not everybody can build it to hold up to a decent power upgrade and if they do the limitations of the design need to be re-engineered. Same with the 68RFE, what can't be fixed needs to be produced and tested.

What about the Aisin? What do you know about it in general? Would it be a better candidate for retrofit into an earlier 5. 9 truck since it is manufactured by another company for installation in more than one platform?

 

[cerberusiam]

What about the Aisin? What do you know about it in general? Would it be a better candidate for retrofit into an earlier 5. 9 truck since it is manufactured by another company for installation in more than one platform?

Not enough to say one way or another. You are correct in that it possibly could be sourced with a stand alone computer since it is not a dodge specific trans.



Its power limit is a big question and what it would take to handle a powered up engine.

 

[HBarlow]

Not enough to say one way or another. You are correct in that it possibly could be sourced with a stand alone computer since it is not a dodge specific trans.

Its power limit is a big question and what it would take to handle a powered up engine.

I"ve tried more than once to find information on Aisin websites. All I have found is brief mention of the transmissions they build and the automotive brands that use them. The Japanese appear to be very careful not to release any information.

 

[cerberusiam]

The Japanese appear to be very careful not to release any information.

Since they "liberated" so much technology from us they are rather careful about showing ANYTHING worth while in print or publication.

 

[Wingate]

I would want the AISIN if I was going to make a change. Behind my stock 5. 9L, I could actually tow with confidence to the full capacity of the truck.

Not really interested in holding 800hp. on a fuse, I would like the transmission to hold 335 hp. for a LONG time, give me six forward gears without worry.

Somebody figures it out, I'm going ALL IN!!!. I have absolutely NO intentions of purchasing another new truck, so spending the $$$$$ on this one is ok for me!

 

[NavyDood]

Do the Cab & Chassis trucks have a stand alone transmission computer or did they integrate the software into the ECU?

 

[HBarlow]

I guess I should know because I own one but I don't have the slightest idea.

I've had it three years and it has just under 98k miles on the odometer. Comparing my truck to EB's, which is used daily hauling a very large tandem axle gooseneck loaded with oil field equipment and approaching 350k miles, I may never need to know.

 

[WOT]

I don't know what the computer differences are, but it seems to me that Marco or like could get a program that runs on the 07. 5+ computers with the engine code of a 5. 9 and the transmission code of the 68RFE/Aisin. Then you just source a computer and maybe some harness changes, reprogram and done. Well... maybe not quite that simple

 

[RustyJC]

I don't know what the computer differences are, but it seems to me that Marco or like could get a program that runs on the 07. 5+ computers with the engine code of a 5. 9 and the transmission code of the 68RFE/Aisin. Then you just source a computer and maybe some harness changes, reprogram and done. Well... maybe not quite that simple

Sounds like the Marketing guys in some of the technical meetings I've been in. They tell the Engineers something like this, and the Engineers whisper among themselves, "Yeah, it's really easy if you say it fast. " :-laf



Rusty

 

[WOT]

Well, I am an engineer (software). A good challenge is fun... it's the bean counters that get in the way. They are always trying to make money

Sounds like the Marketing guys in some of the technical meetings I've been in. They tell the Engineers something like this, and the Engineers whisper among themselves, "Yeah, it's really easy if you say it fast. " :-laf



Rusty

 

[RustyJC]

Nope, there's nothing wrong with a good challenge, but what I was pointing out is the difference in perspective between the marketing guys (it's easy, I just told you what I need in 10 seconds, so you can have it finished tomorrow, right?) and us engineers who know what's involved in accomplishing it. :{



Rusty

 

[cerberusiam]

Nope, there's nothing wrong with a good challenge, but what I was pointing out is the difference in perspective between the marketing guys (it's easy, I just told you what I need in 10 seconds, so you can have it finished tomorrow, right?) and us engineers who know what's involved in accomplishing it. :{



Rusty

Yep, the laws of physics do not even enter in to marketing discussions. :-laf

 

[AMcCormick]

would it be simpler to just go lower gears in the diffs and then add an overdrive box? You would not gain two gears but you would be able to split what gears you do have

 

[brods]

It appears there might be two potential markets for the conversion. Those with stock trucks that want more gears and hot rodders. In stock form my 05 runs out of top end before it up shifts. Once it finally up shifts and drops the revs it really pulls hard again. Seems another gear or two would help keep the rpms in the power band of a stock truck. For this market a stock 68RFE with the necessary conversion hardware & controller would probably work fine.



Looking a bit deeper, a stock new 4x4 48RE costs $2,711. 50 while a stock 4x4 68RFE costs less at $2,535. 50. If there was a conversion kit available for say $1,000 or less.....



Prices came from here for a 2007 model: DodgePartsSite.com

 

[DogramTD]

Brods; you hit the nail on the head. What you explained is the EXACT reason I posted this thread.

 

[WoodChuck]

Somebody's doing it.

http://www.transmissiontuner.com/68RFE-Swap.html