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moretodo

Hello guys, i am trying to research the prostar with isx with a Allison tc10 and cannot find any drivers info concerning this setup. I am surprised how little information is out there sense prostar had them as a option for 5 years i believe. I have bad knees and want a atm but the ultra shift seems like it is not very popular with drivers. I have learned enough from this site {rawze} to pay attention to the gear ratios.I have read Rawze caution on not having tall enough gears in the rear axle,with the isx. What little i have learned about the tc10 it seems a shame production was stopped.

Rawze

Unless someone has a specific need for an auto-s$itter tranny, then your better off in the long run with a manual tranny for a truck. Auto-trannies are inherently about 0.6 mpg less fuel efficient than a decent driver.. and as well, they have a lot higher maint costs over time. Auto trannies also will lug the engine to death, it is hard to make one rev the engine above 1500+ in a hard pull like it should be doing. They tend to always try to minimize RPM on the engine and this shortens the life of the engine by quite a bit over time.

JimT

problem now and going forward is most fleets have or are currently switching away from manual transmissions on their new purchases. That means it will become increasingly difficult to find used trucks with a manual transmission AND all the other specs you might need. Going forward it seems like manual transmissions will become as rare and as coveted as a pre-emissions engine did. Now, I don't know how hard it is to swap an auto-shift for a manual transmission, but I personally won't be investing in an autoshift any time soon.

moretodo

Thanks Rawze, the lugging is a concern. I may just have to deal with the manual.

JimT

the ultrashift seems to be the most common for non-volvo trucks. I spent 4 years driving a volvo daycab around new england and the NYC and Boston metro areas. For those you definitely need their premium shifter to really take control, but even with the standard shifter it wasn't that bad hauling loads of steel. From what I've heard from other drivers the Eaton Ultrashift is pretty similar to the Volvo I-Shift, maybe even better? Unless I'm mistaken both offerings have the ability for the operator to manually control when to shift and what gear. I think, with the right programming the shift points could be set up to operate in a better rpm range. Sure, probably never as efficient as a good, experienced, caring driver. But lets face it, most drivers are none of those which is largely why fleets are embracing the autoshifts. If you have bad knees or some other problem that makes using a manual problematic then it may be a better choice as repairs to humans tend to be more expensive and painful then repairs to trucks or a slight loss in operating efficiency.

I think one of the biggest concerns about these transmissions when shopping for a used truck is that they tend to pair them with really tall rear end ratios, like 2.90 or worse. Sure you can gear the trans and rears to work together with those ratios but you're still putting more stress on all the components trying to turn the wheels with less input rotations and higher torque. Might be why we (the fleet with the volvo's) saw driveshafts or ujoints break more often with those due to the extra stress at low speeds.

On the flip side, most drivers I talk to like the Ultrashift, as long as it doesn't break down.

SemiSweet

The Allison auto trans I find are complete dogs, never a good gear for the conditions I find either over revved or lugged to death. On the other hand, We have an Eaton 18sp auto in one of our trucks and I was very hesitant to own it at first because of all the reasons discussed. The truck is geared properly with 3.91s. Not to go against all the above but I am pleasantly surprised at how nice it is to drive. They can be programmed to to shift at higher rpm and, while pulling, its as easy as hitting a button to drop or hold a gear to keep the rpm up. It Takes some getting used but if you have bad knees then get what makes you comfortable. I would take a little more maintenance over pain. Could be hard to find an 18 speed auto in a pro star although.

Personally I like my manual and I float the gears but drive very little city so rarely use my clutch.

moretodo

Thanks for the input guys, spent several years on heavy equipment and to steer those old dozers was hard on the knees. Be careful out there!