Automatics - Love 'em or hate 'em?

The computerized part of the transmission, i.e., what does the shifting for you, is what adds a fair bit to the bill.

The auto's I've had experience with have been Allison's. I didn't like them. It doesn't so much shift as it hammers into the next gear.

I'll keep my manual. Both in the pickup and the big truck.

 

An Allison is a automatic.
Most class 8 autos are automated manual transmissions.
The good ones like the M-Drive change better than a driver can most of the time.
Just a fact,
Most of the time giving better fuel mileage than a manual.
Also a fact.
The upcoming I-shift (M-Drive) has duel a clutch and double input shaft , so there is virtually zero torque loss between shifts as the next gear is engaged before disparagement of the previous gear.
It also has a GPS sensor that memories routes so it can learn the road and anticipate when to early shift or hang on a bit.
If it proves as trouble free as the current model it will be a winner.

This also enables the design and tuning of engines for extreme economy.
With a manual they have to design in drive-ability.
The wider the usable power band the easier it is to drive and the less gear changes needed.
This is however not the same characteristics for ultimate fuel economy.
They have engineered a engine that is very frugal but only has a usable power band of 200rpm.
With a duel clutch automated box this motor becomes practical.

 

Anyone know why this guy got banned? I bought he was pretty cool. I must have missed it. Any way we have 4 autos and they always break. They are in freightliners I think there auto shifts. Sometimes I'm on the phone with my coworker and he will have to pull over and wait 10 to 20 minutes for it to " reset" he has been towed in many times to Ryder and they say he doesn't know how to drive an auto?

 

if it's an autoshift and the X/Y units are going bad then there is an issue that needs to be addressed with the supplier. If they are Eaton/Fuller supplied, someone needs to check the dates on them. There was a major problem from '02 til '05 with X/Y units that were built poorly and had a high failure rate, Eaton corrected that problem in '06. We have 9 day cabs with Eaton/Fuller Autoshifts, 4 of them have had either a gear or a syncro replaced the others have had nothing but X/Y's replaced. IIRC, the lowest mileage on these trucks is 380K the highest is probably 700K.

If they are constantly breaking, then yes it is a driver issue. I put 978K on an autoshift equipped Mack, only trans issue was a clutch break that failed at 650K. The X/Y's were replaced 4 times in the first 5 yrs, then once more just before the truck left us. All of our day to day trucks are now Autoshifts, 2 Mack sleepers ('09 and '12 models), 9 Mack Mack CH/CX daycabs, 4 of the CH models have had trans work for internals issues. By comparison, we have one Freightliner with a 9 spd Manual, that trans was rebuilt three times (twice because of dealer screwups during reassembly) and the clutch replaced twice. That is now our absolute last resort spare truck.

 

I guess your joking right. You just put it in D and go. Not sure how that could be driver error. But maybe I'm missing something?

 

Maybe his xy s are bad whatever try are

 

X/Y's are the shift motors that control the shifting on an Autoshift. Yes, if they are constantly breaking the trans, then the drivers are doing something wrong. Occasionally we'll hire drivers who try and out drive or overdrive the trans instead of putting it in D and hitting the throttle. Usually those types either are retrained to get it right, or they go on down the road and do something else. Our fleet of autoshifts has close to 10 million combined miles with only 4 trans needing the cases opened for work, that means we are not doing anything wrong.