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TXBart · 10-03-2013, 01:54 PM

In another thread several people mentioned gearing down on hills. My gasser downshifted on its own, will the Allison also downshift on its own or should I manually downshift?

We haven't climbed many hills so far but will in the next month. The few hills we have climbed the engine did just fine and did downshift in its own to 5th a couple times. If you downshift manually will it up shift on its own when the time is right?

Still learning!

DSL417 · 10-03-2013, 02:22 PM

When in hilly country, engage your engine brake, on the panel to your driver side left. It has two settings. I use the first in somewhat hilly to avoid speeding down longer steep hills. In mountainous where you really need the engine brake, depress it fully. There was an extended discussion of this in an earlier thread, and your probably going to get a lot of input. Reality is, run with what you feel comfortable. In flat or gentle rolling hills, I leave mine off and use the brakes, per the suggestion of the Spartan folks (use the brakes to avoid build ups on the brake shoes to extend the life of the brakes).

TXBart · 10-03-2013, 02:27 PM

I assumed they meant gearing down climbing. I leave my exhaust brake in Low most of the time and have put it in High on a couple steeper descents.

tnrzryd · 10-03-2013, 02:38 PM

Quote:

Originally Posted by TXBart

In another thread several people mentioned gearing down on hills. My gasser downshifted on its own, will the Allison also downshift on its own or should I manually downshift?

We haven't climbed many hills so far but will in the next month. The few hills we have climbed the engine did just fine and did downshift in its own to 5th a couple times. If you downshift manually will it up shift on its own when the time is right?

Still learning!

Vance,

When driving rolling hills, I typically drive on cruise and let the tranny shift automatically when climbing. However, if I'm faced with a somewhat steep climb, I find that if I leave the cruise control engaged, the downshift often times doesn't happen soon enough and the engine will lug a little bit. So, I keep an eye on the rpms and at 1200 I'll manually downshift to 5th, then 4th etc as needed. Again, the magic number for me is 1200 rpms. A manual downshift usually means a manual up shift. After awhile you will learn what works best for you. Another thing is that approaching a steep hill in cruise means that you can't get a run at the hill so for me, I cancel cruise in advance so I can enter the hill with a little extra speed.

TXBart · 10-03-2013, 02:45 PM

With my gasser I learned to push the gas pedal a little, even with cruise engaged, to build up some energy for the climb which would delay and sometimes cancel the need for a downshift. One of the big reasons for buying our Entegra was the engine between us screaming on climbs.

I still haven't figured out how to deal a with post; I tend to drive with the display in OAT and boost. Will it over boost? What value should you stay below? I have seen 38.0.

brobox · 10-03-2013, 03:32 PM

Allison transmission have a "memory period" meaning they have to learn how you drive. I have found when going down a 6 or 7% grade, the Allison is not the best at remembering I don't want to be going faster than the truckers. I use the jake and manual shift in to the gear that gives me a comfort speed for going down hill.

Going up hill, I will normally down shift before the Allison does, I won't let the RPS fall below 1500. The Allison is sometimes late on that and it's hard to get the RPMs back up when pulling a grade.