Right on about auto shifts increasing the pool of drivers that can handle a big rig and they are not just steering wheel holders as the demands and responsiblities for over-the-roaders is huge, it doesn't end with manual gear jamming, althought that does sort the men from the boys.
The class 8 rigs don't get the Allison torque converter trannys and they get the solid clutch autoshifting trannys when a fleet or owner operator orders them that way. Eaton makes their clutch pedal (used only when starting and stopping) autoshift in 10 speed and 18 speed versions. The 10 speed added about 4000$ and the 18 speed 7000$ to the cost of the rig but Eaton was guaranteeing them for 750,000 miles. Eaton also makes an Ultrashift 10 speed that has no clutch pedal, like their competitor the Freedomline. An Eaton rep told me that their autoshifts are not retrofitable into rigs that came with a standard tranny.
The Freedomline with a servo actuated clutch is made by Arvin Meritor which is a Volvo subsidiary that bought out Rockwell. It is a creation of ZF in Germany and there have been legal challenges between Eaton, Arvin meritor and ZF but I think they have been resolved without putting any of these off the market. Most common Freedomline is a 12 speed but they have offered a 16 speed. My fleet contact says that in spite of the servo clutch the robustness of the Freedomline equals the Eatons; they all can give trouble surprises that you see coming with a standart tranny-clutch set up.
Established big truck dealers now commonly have some mechanics who have been to the mfger's school and getting an autoshift taken care of is pretty doable, just takes $$$. Fuel economy does not suffer like it does with fluid coupling/torque converter transmissions and their lifespan competes well with standards, possibly less prone to driver stupidity/abuse. Probably the less stop & go the service, the better the autoshifts fit in. Torque converter tranny is probably best for stop & go applications.
For an RV the autoshifts make a lot of sense for family driving since they evaporate the need for gear jamming skill but the driver still needs some amount of trucker's intuition.
The Eaton autoshift made a believer out of me in over the road driving and now I've got a Freedomline rig for conversion and it is OK too but has it's differnces in how to best manage it.
Enough of this wind.
medent, El Paso
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