Auto shift in class 8 trucks.

[puros_bran]

Back in the 90's I worked for CalArk trucking. CalArk was the first company that tested the then new EATON AutoShift for Class 8 trucks. Basically a computer that sits atop a manual transmission and does all the shifting for you. I despised it. Coming down Cabbage or Donner out west or even Sandstone over in Virginia without being in control was terrifying. For the next 20 years I avoided working for companies that purchased them, going so far as quitting a pretty decent job hauling for Lowes when the boss decided to purchase all new trucks with auto shifts.

I just watched a video on the Daimler DT12. I actually wish I could try one.  It looks like 20 some odd years of upgrades has gotten the bugs out.  Anyone drive one?

 

[Puff Daddy]

I'm not sure exactly which transmission it was, but I drove a Peterbilt mixer for a few years that had an automatic. This was roughly 2009-2013. I think it was an Eaton but I'm not 100% sure. If I recall it had 6 forward and 1 reverse, can't be sure now. It was a POS. The company I was working for bought a bunch of them because they were supposed to be more econimcal. They got no better fuel economy, they shifted horribly (not where I'd shift them manually, that's for sure), they lurched you forward on the downshift, and since we do so much offroad work that requires the slow deep reduction gears a manual Eaton has, they were god awful to pour out with (you need to move forward slowly 6 inches at a time, but you lighten up on the brake and you get a 12 inch lunge). Plus, when driving a heavy load on soft unstable rough ground they would bog down and then lurch about trying to catch up to the torque needed. Your only choice was to mash down and barrel through and hope nothing gave way underneath you. Seen several of these stuck for that very reason.

The only positive I can note was that, on simple goin down the highway loaded jobs, with the engine brake engaged, they drove easily enough and stopped easily.

One night, while doing highway work with type 3 rapid set concrete (nasty stuff, stop the drum and it immediately begins setting up, you can drive a truck on it a couple hours after pouring it) I had just left the plant with a load. My truck had just come back from the dealer that day for transmission work. Got about a half mile from the plant, made a left turn and put my foot into it and the whole thing came unglued. Horrible crashing metal sound and the motor died. Apparently something bound up and then broke and the computer went into fatal error mode and shut off the motor. The computer refused to let the engine restart, and by the time a mechanic showed up (10 minutes) it was over. The concrete in the drum was solid, lost the drum. The transmission company (via the dealer) had to pay for not only the transmission repairs but a new drum, salvage bill for the old drum, wrecker, etc..

Yeah, bad idea, manual transmission only please.

 

[puros_bran]

Those are class 7, no?
Regardless, I'd agree. On Higheay: (from the video I watched) 1 please. Off Highway: No thank you.

The first Hoods Youngblood Truck Lines bought in the early 90's were these Cement Mixer rejects. Had a L-10 Cummings in it. These big old massive steel bumpers and an RV motors. 9speeds. Absolute useless for what we were hauling. But they were shit loads better than the FLD112's they bought to replace them. Same L-10, 36 inch flat top sleeper, 9 speeds, passenger seat/shelving/etc removed, aluminum rims not for style but for weight. We were the only company that could haul 52,000 lbs out of the paper mill,but I bet we didn't average 40mph criss crossing the Appalacians with those buckets. The chief f%*^head in charge of douchebaggery discovered it was 18 miles shorter to cross over on US25E instead of riding I40 out to I75 and demanded we all go that way. The problem was it was almost 2 hours longer because of the hills. He saved the company a lot of money with his routing programs by reducing fleet miles. :shock: :shock: :shock: I bet he cost them $400,000 a year in less than $1 a gallon diesel with his superior intellect and his swagger.

 

[Carlos]

Probably not at all similar, but I drove a typical snowplow truck that had a 2-speed automatic. Hated it. When I climb up into a truck, I like finding a manual transmission. But I also never drove anything bigger than box trucks.

 

[Richard Burley]

Probably not at all similar, but I drove a typical snowplow truck that had a 2-speed automatic...

:lol: What? A PRNDL column mount? Heavy duty, man. I've never driven real trucks either, but autos are cool on something like scrapers. I've operated a Letourneau stick, and, ah...you don't want to miss a shift in certain situations.

 

[mark]

I drove part time delivering house trailers point to point a couple years ago and the truck had an Allison T10 automatic in it. Low gear was too high and bogged, gears 8-10 were too high for the application but you couldn't lock them out so it was a nightmare. Constant shifting and lurching,,,listening to that thing downshift sounded like 7 tomcats in a burlap sack. :fpalm:

 

[AJ]

Come on guys. More of these stories please. :bounce: :bounce: :bounce:

AJ

 

[puros_bran]

The Allison Automatic is a completely different beast. An completely inappropriate for much more than a garbage truck or pulling a RV as a consumer.
A lot of the RV/mobile home haulers out of northern Indiana buy the Allison for their first truck and then never go back to it again specifically for the reason Mark stated.

 

[Puff Daddy]

Come on guys. More of these stories please. :bounce: :bounce: :bounce:

AJ

OK, but this one shows one of the few positives of having an automatic in a heavy truck.

The mixers I drive weigh about 27,000 lbs empty and carry an additional 40,000 lb payload. We're not pulling that weight, we're carrying it. When the tag axle is lifted (which you must do when offroad or anytime you back up) that weight is mostly perched on two rear drive axles, but the weight is well up off the frame because it's in an angled drum, and that drum is moving, and the payload is constantly turning over and climbing up the drivers side because the fins inside the drum lift the semi liquid load to that side while the drum is in charge (discharge and the weight shifts to the other side).

We were doing a project downtown. Imagine a square city block completely excavated three stories deep, a perfect huge square deep hole. They needed concrete down in the bottom to shore up pilings. Instead of pumping it down from the street they built a steep narrow dirt ramp that wound down around two of the four sides, and you had to back down to reach the pump truck below. It was pretty sketchy to say the least. It was so steep that the manual shift trucks, even with the deep reduction, created big problems because even the slightest let-off on the accelerator or touch of the brakes, even when going that slow backing down, caused the front end to raise up and the front tires would come completely off the ground. Then the attempt to stop the truck by braking harder when that happened would cause the truck to skid because the grade was so steep and the trucks were so heavy, and of course you could not control the direction of the skid because the front steer wheels were not touching the ground.

We had a couple of younger drivers almost lose their trucks. Twice I had to back a truck down for another driver and then walk back up outta there :x  scared the shite outta some of them. One guy told management he couldn't do it again and said he'd just park the truck outside the job and walk home if they sent him back.

But the Petes with the automatics (I had one at the time) were perfect because you'd start your descent backing down and as soon as you hit the steep grade you'd manually shift it into the forward 1st gear. The weight of the truck on the grade in reverse worked against the transmisssion trying to creep forward and the result was a perfect slow smooth descent backwards down the grade. It was actually the only way to do it because reverse and using the brake would instantly lift the front wheels off the ground.

It was enough to drive a man to drinkin, thank god    :drunken: