I been looking and waiting to see if anyone has info on this. W/ the 6sp auto trans coming out for 07 models, whether it's the Aisin or 68 RE, will the early 5.9L 2007 models still run the old 4sp auto trans, or will they be available w/ a 6sp auto.
I think the best combo would be the "old" 5.9L w/ a 6speed auto.

 

It's not likely they'd go through the effort of having the 6 spd tested with the old 5.9 for a short run of "orphan" trucks. The 68RE is listed as late availability I believe.

 

I agree with Berak. All driveline combinations have to go through an EPA certification process (read-$$$$). It makes no sense to certify the new transmission with the old engine for such a short production run.

 

I just say an ad the other day in 'Trailer Life' for the all new Megacab dually with a new 6.7l motor and a new 5spd automatic transmission? It was in print as a Dodge ad?

 

Not likely, it was probably referring to the 5 spd. auto behind the hemi OR the 6.7L diesel.

 

Yeah, I knew it was probably wishful thinking. I am still considering getting a MegaCab before they go to the 6.7L, I just don't dig the higher rpms of the 4sp auto, or the 6sp manual at highway speeds.
I don't tow that heavy and do alot of empty highway driving.

 

The 4 speed auto doesn't have high rpms at highway speed (in OD). I've done over 100mph with the stock tires and only ~2500 rpm. The one problem with the 47/8RE IMHO is that the step from 3rd to 4th is too big (the turbo bark at 45mph while pulling a trailer reminds me of that all the time). Conversely, when pulling a hill and the tranny downshifts from 4th to 3rd there is a huge jump in RPMs (right up to redline in 3rd at 70mph), another gear in between would be just the ticket, and it appears that's what we'll get in '07.

 

Hmm, I've only test drove a couple, but I remembered being at 2500rpms at about 85 mph. Might've been a 4.10 rear end.
The big gap between 3rd and 4th wouldn't kill me too bad as I don't tow very heavy.
07's should give 2 more cogs, correct? Does anyone know the gear ratios for the 6 speed autos? Will they be a dbl OD, or just better gear splits for hauling w/ 1 OD gear?

 

The 6spd's are going to be tied up with a 4.10 Gear ONLY!!!!! WHY???? You got me. That is what all of the reports are saying.

 

Maybe because of the double OD?

 

Hopefully they will do a better job with the 6-speed than they did with the HEMI 5-speed. They need to redo all the ratios and not just slap extra overdrives to the existing ratios.

 

my 3.73 4x4 does 1800 rpms at 65 mph and about 2050 at 75 mph

have never hit 2500 when empty even doing 90+

get the 06 if you can swing it now, the 07 diesels are supposed to need a fuel additive at least in my part of the country