Driving with the Allison Automatic Transmission

[BIGBIRD130]

We are renting a 2008 42' Tiffin Allegro Bus with the Allison Automatic Transmission
Is there anything special you need to know about using it?
I've driven a tractor trailer but that was a 10 speed standard
Thanks for any help

[CA_Traveler]

No reason to switch to N for stop lights. It takes a much more extended time in grid lock before the tranny temp starts any significant rise.

[Blaster_Man]

bluwtr49 wrote:
One thing you will notice is that the engine develops so much HP and torque even at idle that holding in gear with brake is not particularity easy and the tranny will generate quite a bit of heat.

It pays to kick the tranny into "N" at stop lights.

Agree. The only time my trans temp has risen was when we were on the interstate, there was an accident and the traffic stopped. Put the trans in neutral and it immediately cooled down.

[bluwtr49]

One thing you will notice is that the engine develops so much HP and torque even at idle that holding in gear with brake is not particularity easy and the tranny will generate quite a bit of heat.

It pays to kick the tranny into "N" at stop lights.

[bycrackey]

rr2254545 wrote:
Need to downshift manually going up hills and mountains unless you want to go really really slow.

its a 425ISL and has lots of power plus its not a Exhaust Brake
its a 2 stage engine brake.Big difference!
Have the person leasing it to u explain how and when to use this function.For the most part just leave the trans in D for 99% of your driving

[wa8yxm]

My gasser has a 5 Speed Allison, in my case the MODE switch is labeled "Grade Brake".. if yours is then post and we will describe its operation to you. otherwise..

I mostly put it in "D" and let it do it's job.. I've driven over mountains and flat land and I just let it do it's thing. I've not noticed it dropping below the torque curve before it shifts but then it has a GM engine in front of it and it's kind of hard to drop below the torque curve on those.

It works well.

There are some places where I will downshift.. Mostly because in the RV parks the speed limit is 5-15 MPH and I very much need to keep it in low.

[Snomas]

I think the the most important thing to learn is how to use the exhaust brake on downhill grades to control you speed whereby you don't overheat the service brakes causing them to overheat and fail!

[wolfe10]

All correct opinions except that the Allison 3000 and 4000 series lock up at higher RPM in SECOND gear, not first gear.

And as you can see, you can either "let it do its own thing" or you can use the up/down arrows to proactively choose a gear.

It will not do anything that would endanger the engine or transmission. Said another way, down arrowing to 1st at 60 MPH would cause the transmission to downshift one gear, until road speed lowered to where it was safe to downshift again-- all the way to first.

Particularly if you want to treat it like a manual transmission and YOU select the gear, push the MODE button which selects economy mode. That allows the engine to upshift earlier and downshift later (exactly what the engine manufacturers recommend for economic driving. Then if you see a steeper grade, use the down arrow to select a lower gear.

OR, if you want, just let it in "D". Gears and gear changes will be OK, but not ideal, since the transmission is REactive (responding to what is behind you), not PROactive (responding to what is in front of you).

[Blaster_Man]

Last summer we crossed the Continental Divide...put it in "D" and never touched it. Going down the other side, used the engine brake, never touched the service brakes. Great transmission.

[Valkyriebush]

Thunder Mountain wrote:
I have a couple of comments about the 6 speed Allison in my '07 Endeavor. On flat ground like Kansas, just put it in D and go to sleep. However, if you are in mountainous areas you my need to do a little shifting on your own. The tranny can't "see" that long grade that will have it downshifting a couple of gears before reaching the top. By the time the tranny decides to downshift, you are behind the torque curve. Or you can just sit back if you really aren't in a hurry.

X-2, also on flat land I set the tranny in Drive/Economy mode.

[rr2254545]

Need to downshift manually going up hills and mountains unless you want to go really really slow.

[jgolden]

Just push the "D" to go and the "N" to park. Mine is a little older but generally the Engine brake and the tranny work together. Mine will shift up to avoid over Rev on the Engine the newer may be a little different but I doubt if is much.

Get a good idea of how the systems work, Leveling jacks, slides ect, don't leave home with out the operational manuals for all the systems. Get schooled up on hookups when you are in a campground.

No doubt you know this part, but find out how high it is.

Have a good trip. Kind of chilly again in the Capitol district.

[Thunder_Mountai]

I have a couple of comments about the 6 speed Allison in my '07 Endeavor. On flat ground like Kansas, just put it in D and go to sleep. However, if you are in mountainous areas you my need to do a little shifting on your own. The tranny can't "see" that long grade that will have it downshifting a couple of gears before reaching the top. By the time the tranny decides to downshift, you are behind the torque curve. Or you can just sit back if you really aren't in a hurry.

[JimM68]

mostly you just ignore it and it does it's thing.
It will not allow you to over-rev, it will upshift regardless of what you tell it to do.
With the exhaust brake switched on it will seek to second when it can, and it will bring the rpms higher than it does under power, this is normal and not a worry.
The exhaust brake works pretty well, but not like the jake in your truck.

They lock up the torque converter at the top of first, just prior to shifting to second gear. Kinda feels like a "double shift" or like something is slipping. Threw me at first, but have been assured it is normal.

I never shift manually, just put it in drive, and use the exhaust brake switch as needed.

[bluwtr49]

Find out the operation of the exhaust brake and the default tranny gear.

Aside from that the Allison is pretty smart. There is a mode button that enables different shift parameters allowing you to lug the engine for increased economy.

You might also have the owner explain how to check the fluid level using the keypad.

Have fun and enjoy.