Autoshift, or not?

[sled dog]

Gentlemen, a farmer friend bought a '14 Pete 384 yesterday with an autoshift. 1st one either of us has ever been around. On the test drive, and following him home, I noticed it runs thru all the gears. Now, if it had been a regular trans, would have normally left the stoplights and signs in maybe 3rd. Didn't have that option with the autoshift. Or do we? Dash mounted push button shift select. Bobtail, or empty trailer, can you stop at a stop sign, select manual, bump up to about 3rd and take off. Up to speed, then select drive and allow it to finish shifting itself? Hate to take the eyes off the road for complete manual shifts, but can you just do it once to go from manual to auto?

 

[lantraxco]

Try it.

 

[Edward Porter]

advance it to any gear you want to start off with. off road and steep hills and downgrades use the manual button then advance the gears with the arrow buttons. It should skip gearsin auto if they are not needed I have a 1st generation 18 spd auto shift. I like it. Not worn at the end of the day

 

[sled dog]

Lantraxco, Edward, Thank you. Was servicing today, maybe some driving and learning tomorrow.

 

[crane operator]

The one I drove would automatically start in 3rd unless you manually downshifted it into 1 to take off at a stoplight. It was a ZF 12 speed. I haven't driven a eaton one.

 

[Truck Shop]

As said above. But one thing about Eaton auto shift transmissions, The transmissions can lurch in forward and reverse and tough backing under a trailer especially in winter conditions.
If the Solo clutch gets grabby or slightly out on it's self adjustment you can easily slam the trailer king pin, very common problem that exists with all Eaton auto-shifts no matter the make
of truck. Reason--------The transmission is made to cover several types of engines/ECM's. Where as it wasn't specifically designed to communicate with a single brand of engine.
The Detroit DT12 transmission combined with a Detroit DD13, 15, or 16 is a way smoother transmission with many more capabilities.

 

[sled dog]

Truck Shop, yes on the lurch, literally the first thing we noticed pulling out of the parking spot on the dealers lot. Odd to be this old and starting at the bottom of the learning curve. Oh well, a day we don't learn something is a wasted day. And Thank You !

 

[Nige]

I had a bit of a search and there are a number of instructional videos, includsing one from Eaton, on how to shift one of these transmissions. I imagine that possibly different OEMs might just have different types of shift control though. This might be a good place to start.

http://videos.eaton.com/roadranger/...t-transmission-driver-training?autoStart=true

 

[Pops52]

I watched the video, it seems to be complicated. Lots of taking your eyes off the road and still a clutch comes into play (or not)? I drove a Volvo 12 speed autoshift for 2 days a couple years ago and didnt like it but amazed at how the thing worked. I give them a thumbs down but then, I'm an old coot. I like the 18 speed manual........

 

[Truck Shop]

The early models of Eaton Auto Shift had a clutch pedal, but that was dropped about nine or ten years ago now and that model is called Ultra Shift plus. Clutch is operated electronically.

 

[mowingman]

For the last 4 years, we have had at least one leased tractor that was an automatic, to pull band trailers in our school district. I have had kind of a love hate relationship with them. Yes, they are great in heavy rush hour traffic, and traffic jammed freeways. However, I found them very slow to shift and it thus took a long time to gain speed after stopping at a traffic light. I also have experienced the "jump" in reverse. In fact, I had a lady band director that almost got run over, by me, when reversing a trailer.
I finally decided the best way to drive one on the road was to leave it in drive, and just put my foot to the floor, leaving it there until I reached the desired speed. This year, instead of leasing, they bought 4 Peterbilts, all with automatics. I am kind of glad I retired from that driving now.
Jeff

 

[Birken Vogt]

Somebody remind me again, what is the disadvantage of an Allison transmission? I have worked with the Allison man to get the shift points tuned just right on new trucks and after that they are really nice to drive. But there is never any lurching because it has a converter the same as your car, or any tractor, or garbage/fire/dump truck.

Maybe they consume more fuel over the road, don't know about that one.

Maybe the manufacturers would rather sell their own proprietary transmission.

 

[Truck Shop]

Despite Allison claim of better fuel mileage which is false. Service centers are too far apart for one thing the other is warranty. Detroit Transmission will cover to 750,000 miles. AMT transmissions have become reliable. Third-manufactures want to sell their stuff. Fourth-a truck is then all one brand and manufacture has less chance of a pi$$ing match with a vender. which is pretty common these days.

 

[Pops52]

Somebody remind me again, what is the disadvantage of an Allison transmission? I have worked with the Allison man to get the shift points tuned just right on new trucks and after that they are really nice to drive. But there is never any lurching because it has a converter the same as your car, or any tractor, or garbage/fire/dump truck.

Maybe they consume more fuel over the road, don't know about that one.

Maybe the manufacturers would rather sell their own proprietary transmission.

@Birken Vogt If I could find an automatic in a big truck that worked as well as the auto in my 02 GMC I might like that. Also I see we are in the same area, I drive the lowbed for C&D at least til I try to retire (again) at the end of June.
Dave

 

[Birken Vogt]

Your 02 GMC, is that the Allison or the GM transmission?

The Allisons in the GMC of that era were nice, but in a medium duty, the same transmission had the more "commercial" shift points and was even better.

First gear, converter, inch around all you want. Take off down the road, it shifts to second, and midway through second gear, it locks up the converter. From there on out it becomes a solid locked powershift transmission basically and the converter stays locked at all times, until you slow down.

The big ones work pretty much exactly the same. Regular is 6 speed but you can also get them in a 7 speed version which has a granny low. 6 speeds does not sound like a lot but it pretty much just works.

I am sure there is a penalty to pay for running the big oil pump all the time, but it has to beat replacing clutches, u-joints, king pins and any injuries to a person on the ground who got hit because it lurched.

Line haul I am sure that the scales tip in favor of the AMT but for short trips with lots of stop and go and manuvering I think an Allison would at least be worth a look.

 

[DMiller]

Local mail hauler and a grain/fertilizer hauler have AMTs, NOT happy with them on secondary roads they frequent with sudden onset hills as the mechanisms cannot 'anticipate' a gear change where the drivers tend to run them in over ride to get them to run optimum speeds. The company owners spec'd straight manuals next run of replacements.

 

[Truck Shop]

Really until a person drives a DT12 in slow hilly condition or on highway-it can't even be compared to the rest of AMT's or Allisons. The 12 is a pretty smooth transmission. And rated for high hp and torque.

 

[Birken Vogt]

Really until a person drives a DT12 in slow hilly condition or on highway-it can't even be compared to the rest of AMT's or Allisons. The 12 is a pretty smooth transmission. And rated for high hp and torque.

Does it operate the same was as a classic AMT? Sliding gears in and out? They just put better programming on it? Or is there more to it than that.

 

[Truck Shop]

Check this link. In creep mode there is no lurching, smooth. And helical cut gears zero noise.

https://www.oemoffhighway.com/drive...on-detroit-dt12-automated-manual-transmission

 

[Crummy]

If I could find an automatic in a big truck that worked......

Did Ron get his new truck figured out? Last I heard he wasn't too happy with the auto trans.