I have never had an automatic transmission apart, but I believe I understand the mechanical workings at least at the conceptual level (for example, a 48RE:

Planetary gear sets can create several gear ratios with one set of gears by using bands and clutches to hold a certain gear stationary while the others spin. To shift to a different gear ratio, bands release a gear and "clamp" another. The torque converter provides the fluid-turbine link between the engine and the planetary gears.

A very good salesman (honestly) told me that the Allison transmission is a direct-drive transmission and that's why it holds up so well. So how does it work? There still has to be a torque converter and clutches to shift from gear to gear. What about the bands-----does it have them and do they get sloppy and need adjustment or replacement like the 48RE?

Now, my real question.........what are the inner-working principles of a 68RFE?

 

the 68rfe is a bandless transmission, which means it doesn't use bands to hold any drums (as such with the 46, 47, 48re's). it uses flat single and double sided frictions. i dont know what a direct-drive trans is by definition but i dont think it would describe the 68 or the RFE trans family.

the clutch arrangement is simple, it has an inout assembly that has three clutch groups in it, OD, UD, Revs. and then three setsof holding clutches 2c, 4c, and a low/rev. plus three planatery gears sets. to get you to 6 forward gear ratios and one revs.

this is simular to the allison in that they are both bandless. if you want info on specific components let me know. i just spent a whole day studying this trans.

 

isbeinside,

Thanks for the description. It sounds like the 68 is ALL new, modern and not an upgraded 48. That's a relief. I wonder why Chrysler designed a whole new tranny and also decided to use the Aisin in the CC? Is the 68 weaker? or unproven? or they can't make enough? wrong gear ratios for the CC? Hmmm.
Did they mention that at the training?

Thanks,

John

 

Aisin has a PTO...68rfe does not...well that and a 2000.00 difference give or take.

Richard

 

raychem,

You mean the Aisin costs $2000 more than the 68?

John

 

Yes it does...$ 2295.00 for the aisin and $ 405.00 for the 68 rfe. An 1890.00 dollar difference!

 

There's got to be some other differences too. When talking with suncoast about retrofit possibilities, they said the 68rfe would not be able to do it. They didn't explain why. They also said the aisin would be a good candidate but they were not going to pursue it because they are trying to sell the allison conversion (at 10k!) and have put a lot of R&D money into that. Also, the aisin is classified as a medium duty transmission.

 

GVWR of the two trans are very different, there are many factors behind that, some of which i dont know, but between the GVWR of the two trannies and the initial cost of the units (545 and 68 RFE made by DC compared to the AS68RC made by aisin)is the biggest reason.

 

Looks like the right person answered my question! Thanks for the "real" facts. It sure sounds like a good transmission if it holds up. If they had a better air-conditioner, I might just be swayed to suffer thru the payments on a new Dodge 6.7L instead of looking for a used DMax with a cold A/C and no bucking from the rear suspension!

 

The 68rfe equipted 07 ram 6.7 beat both the d-max and ford 6.4 in recent head to head shoot-out in Detroit,both 0-60 and 1/4 mile .The times were still about the same as 48re and 5.9 high 16's and low 80's.I guess the emissions take a toll.