A Manual AND an Automatic Transmission

[Gary Hatt - Publisher BCM]

I would like a Manual Transmission in a bus for traveling in the mountains but I prefer an Automatic Transmission for city driving. 

When I was growing up in the 60's, my neighbor owned a garage in Charlestown, NH and he built a car (not sure of the model as I never actually saw it) with both and Automatic AND a Manual transmission. He had one mounted in front of the other.

When he wanted to drive using a Manual Transmission, he somehow locked the Automatic Transmission in direct drive and used the clutch. When he wanted to drive with his Automatic Transmission, he would lock the Manual Transmission in direct drive or high gear, not sure which.

Has anyone else done this that you know of as this would solve my problem?  I have pondered this arrangement for years.

[luvrbus]

You could do that with the old fluid drive in Chrysler products way back 

[Brian Diehl]

Not exactly what you are asking, but an Eaton Autoshift (GEN 1) is pretty close to what you are talking about.  It is an automated manual transmission.  You can choose between automatic and manual modes for shifting.  In manual mode the transmission shifts only when you command it to shift.  In automatic mode it shifts automatically.  The GEN 1 model uses a clutch to get rolling and to stop.  So - you still have a clutch.  All other gear changes are done without the use of the clutch through computer controlled RPM matching.  With 10 gears to choose from you are always have the ability to be in the best gear for the moment.

In the mountains I tend to use manual mode because it allows me to lock in a gear.  This is especially helpful when going downhill as I can stay in a lower gear allowing for greater jake brake engagement.  Otherwise in automatic mode the computer will assume an upshift is appropriate and change into the next gear.  This reduces the engine RPMs which also reduces jake brake retarding power.

Much like a regular manual transmission, shifting entails letting up on the fuel.  This means an extra second or two on each shift for the turbo to spool up again.  This is the single biggest negative to the automated manual transmissions.  With a fluid drive automatic the turbo stays spooled up and making boost across gear changes allowing for smoother delivery of power.

[6805eagleguy]

I'm pretty sure unimog's have a fold out clutch pedal with a type of auto shift trans.

Fold out clutch and shift manually, fold in clutch and drive like a automatic

[Ed Hackenbruch]

Easy solution Gary,  if you have an automatic now, just buy a bus with a manual and put a trailer hitch on both of them and a tow bar on both. Then you can drive whichever one you feel like and tow the other.....upside is you have more storage for stuff and a sleeping area for company! No need to thank me for this great idea.    

[luvrbus]

Install a lock up valve on the Allison converter and drive it like manual shift with the shift tower to change gears ,you get more power to the ground with the torque converter in play,that is the reason Allison the AT 10 has the automated Eaton and others playing catchup   

[TomC]

Even with my V730 only having 3 speeds, if I pull the gear shift down to 1, I get torque converter lockup as low as 22  mph. This facilitates going up long grades at 32mph fully locked up. And coming down with very powerful braking from the Jake brake. If I do rev it to 2,400 in 1 it will up shift to 2nd. But 2nd will not shift to 3rd if over revved. So at least with my V730, it acts like a 2 speed transmission with 2 speed torque converter (slip and lockup) with overdrive 3rd that shifts according to speed only. I really love that transmission-only wish I had one more gear. Good Luck, TomC

[CrabbyMilton]

Tom pretty much said it. Just use an AT like a manual and restrict the upshifts.
My work van is a '16 FORD TRANSIT CONNECT and it has the little up and down button so I could use it like manual. I've tried it at times and it gets silly after awhile.