It's official! 6.7L: 350/650 and 68RFE

[RustyJC]

I don't discount that the 05 weighs more. I meant comparable in terms of configuration (extended cab 4x4 dually, tall gears, automatic, OEM tire size). But if I could swap powertrains between the 2 trucks, the heavier 05 with the 12 valve would still get better mpg. The fully mechanical fuel system was far more efficient than the three-shot EFI. I'm sure plenty of people would trade the quiet for a few more miiles per gallon.

The primary difference is emissions.



Rusty

 

[amsoilman]

The primary difference is emissions.



Rusty

Yes, EMMISSIONS, but ALSO double the power of the 12V engines, the fuel economy is going to suffer! :{



Wayne

amsoilman

 

[AKaiser]

My friend has a VW that has an auto that you can shift manually - and not just 1st and 2nd. You can drive it like a manual through all of the gears in the transmission. Is there some reason that DC couldn't make our transmission's do this so we have the benefits of a manual with the drivability of an auto? This would be the best of both worlds if it was engineered well.

Sounds like Auto-stick, but that's just a regular automatic Torqueflite type transmission with "manual control" Something else to consider (they have alot of these in Europe. ) It's called a dual-wet-clutch transmission. It's actually an automated standard transmission. The reason he can shift it like a manual, is because, essentially, it is sort of a manual, designwise, but somewhat like an auto, minus the torque converter. Kinda like a power-shift transmission in a tractor.



Dual Clutch Transmission

 

[CUMMINZ]

I'm waiting on a 5500 with auto.

 

[mlewis73]

Glad I bought my '06 six speed... Sounds like Dodge is playing the higher RPM game now.

 

[NWhitney]

VW Engine/Trans package

Ok so I know this is not a VW site but here is what the VW's do. In the earlier PD (read unit injector like the big cat's and cummins) engine they used a regular automatic that is fully controlled by solenoids (sounds like the new RFE). That is what is in my wife's '04 Jetta TDI with 40K miles(47 MPG). When I drive it I tell it when to shift... little tap ahead shifts up, tap back and down shift. Get lazy?? Back to the big D and it does all the work.

Now VW has a new transmission called DSG (Direct Shift Gearbox) AKA automated manual trans. This thing as two input shafts that run after the converter. After that it has standard gears inside not bands or clutches, shaft one has gear 1,3,5 and shaft two has gear 2,4,6. Start car and put in D and first gear is set on shaft one. Motor down the road and shaft two is put on standby already in 2nd. Ready to shift, shaft one disengage, shaft two engage 2nd gear. As soon it gets into 2nd the first shaft (shaft one) shifts to 3rd. And so on and so forth. On a car with the same PD engine (same hp and tq) and heavier (Mk IV vs Mk V) an '06 (my mom's car) with only 6k on the clock gets 50-52 easy.



Why can't DCX make its own very big DSG. An automated manual trans is what we all want. Don't loose the big power of the gears and yet let a computer shift it for you when you want and let you shift it when you want. Is that too much to ask????????



Dura-Trash already has a trany you can shift with a touch up or down!! Now I want one for an engine that has all off its cylinders in a row... as Mr Diesel intented.

 

[Foil Freak 1211]

I shudder to think of the R & D costs associated with making an "autostick" transmission stout enough to hold up to the demands users of this site would expect.

 

[cerberusiam]

Why can't DCX make its own very big DSG. An automated manual trans is what we all want. Don't loose the big power of the gears and yet let a computer shift it for you when you want and let you shift it when you want. Is that too much to ask????????

That would be something on the order of an electronic Allison 3000 to stand up to the demands of the Cummins. Add $10k to the price, redesign the body to accomodate the size, and loose cab room.





Not gonna fly with the consumer. Not gonna happen with the bean counters.

 

[nickleinonen]

a proper powershift transmission could be made to fit in the space avalable. . if the gear ratios are close enough [say 8 speeds fwd total] gear 1 & 2 [maybe 3rd] would be through a torque converter, and everything else would be direct from engine [either TQ locked or separate input shaft]. cat did this with their scrapers with some of their models years ago. .

 

[KCJackson]

Why can't DCX make its own very big DSG. An automated manual trans is what we all want. Don't loose the big power of the gears and yet let a computer shift it for you when you want and let you shift it when you want. Is that too much to ask????????

If you mean an automated manual like the ZF AS-Tronic, I'd go for that. For those not familiar with this concept, it's a manual transmission that has a computer controlling the clutch and shifting instead of a clutch pedal and hand-shifter. Unlike a regular automatic, an automated manual can skip over unnecessary gears - for example, if you have a 7 speed automated manual and you're running empty, the computer will realize you only need gears 2, 4, 6, and 7 to get going, so that's all it will use. The 10-speed ZF AS-Tronic has been a big hit in the motorcoach industry. It weighs much less than the Allison B500, and the additional gears replace the "low" gear effect of the torque converter before it locks up.

 

[FATCAT]

The last thing I would think you would want is a computer controling the transmission. Any person with half a brain and some manual dexterity can shift a transmission and choose the correct gear better than any computer. And computers tend to fail.

 

[DJW]

Not aware of the date first used in Britain, but a Diesel bus I rode daily in 1940 had what the driver called a Pre-Select or Pre-Selective gearbox, absolutly no feeling of gear change when sound of engine changed when running up hill, quite a lot different to the Petrol engined buses at that time, which would shake you in the seat, as they were so underpowered.

 

[HNelson]

I'd be all over a dual clutch auto attached to a Cummins! But unfortunately I don't know of anyone working on such an animal :{ (If there was, I'd know).



The mechanicals are far as gears, packaging, weight, and efficiency are like a manual transmission. The automated shifting shifts much faster than anyone can shift a manual and it uses the dual input shafts to do a "powershift" between gears. No more dropping boost during shifting. The best part is the shifts are super smooth like a traditional auto, way better than a single input automated manual (like Ferrari's F1 box or BMW's SMG). The only real downside of the package is taking off from a stop... not quite a nice as a torque converter automatic.

 

[NWhitney]

Close to perfect...just too heavy

Here is what you can get if you buy a Freighliner/MB.

MB AGS

 

[Burner]

I'm a big fan of AUTO transmissions, HD style. However, I have never seen a "big puller" with an AUTO? You know the kind, the trucks pulling well over 150k on a trailer with 9 axels or so... ..... why is that?



On the other hand, I've never seen a manual trans off-road rock-truck, something in the 30-400 ton range? ... ... why is that?

 

[cksh8me]

Don't fight it just breathe deep.



Face it you can put it off but we are going to buy these trucks if not this year next year or the next or the year after that. If we need a truck what choice do we have. NONE



The big difference on choice between the autos and the manual is going to be dictated more by price and package than anything else.



The new 68 whatever is untried and could be junk or great, the aisiin sounds as if it has a good heritage but could be a melon.



If you need a mega cab pickup for the family and you can only get the aisiin trans in a cab and chassis are you going to strap your kids to the roof? No you are going to suck it up buy the mega with either the best deal or wait for the trans of your choice. (unless the wife will only drive an auto)



You can always buy a Ford or Chev but... ... don't you think they will have the same emision standards? I don't think the feds are just picking on DC.



Bottom line drink the kool-aid and lay your $$$$ down.



Good luck and enjoy your purchase

 

[NIsaacs]

I'm a big fan of AUTO transmissions, HD style. However, I have never seen a "big puller" with an AUTO? You know the kind, the trucks pulling well over 150k on a trailer with 9 axels or so... ..... why is that?



On the other hand, I've never seen a manual trans off-road rock-truck, something in the 30-400 ton range? ... ... why is that?

Maybe because on a rock truck the cab is half a mile away from the transmission and manual linkage would be a nightmare :-laf





"NICK"

 

[TAbbott]

Maybe because on a rock truck the cab is half a mile away from the transmission and manual linkage would be a nightmare :-laf





"NICK"

NIssaacs, I don't mean to hijack the thread but I see in your sig that you have a 3 speed Spicer Auxilliary transmission behind one of your CTD's. I want one. Which model do you have, where'd you get it and how much $$ was it? I think that'd substitute real well for the carrier bearing on my 06 two-piece driveline.

 

[AKaiser]

I'm a big fan of AUTO transmissions, HD style. However, I have never seen a "big puller" with an AUTO? You know the kind, the trucks pulling well over 150k on a trailer with 9 axels or so... ..... why is that?



On the other hand, I've never seen a manual trans off-road rock-truck, something in the 30-400 ton range? ... ... why is that?

Check out the Army HET. Payload is ONLY 140k and ONLY has a 5-speed automatic

:--) :--) :--)

 

[JasonCzerak]

Check out the Army HET. Payload is ONLY 140k and ONLY has a 5-speed automatic

:--) :--) :--)

heh, top speed at 70ton, 30mph.