Aisin - no grade braking?

[Powder Extreme]

This is the first vehicle I've owned in many years that will not automatically downshift when on cruise control and descending a hill. Going down a steep grade, with the exhaust brake on, I was 20 mph over the cruise set speed and the transmission still never shifted down out of 6th gear. My Allison of course downshifts, as did the 68rfe in my 2010 3500 and the 8 speed in my half ton.



Is the Aisin supposed to downshift? As good as the exhaust brake works it would be a perfect combo if the transmission would downshift too.



Thanks guys!

 

[jgillott]

I've only driven one 2013 with a Aisin and I can't remember for sure. Does it have a Tow-Haul mode like the other autos? If so, does it make a difference? I can't imagine it not being designed to downshift under those conditions. As you mentioned, even our 1/2 tons will.

 

[Joseph Donnelly]

The Aisin downshifts as needed when engine rpm gets low, when the truck is driven solo; with a trailer it would be best to stay in tow/haul mode.

 

[Powder Extreme]

Was in tow mode and pulling a trailer down a 7% grade. Wouldn't hold me back at my desired 55-60 in 6th. Wouldn't downshift. Lowered cruise setting to 40. Still wouldn't downshift. Just kept gaining speed till I manually put it in 5th

 

[Wertles]

Was in tow mode and pulling a trailer down a 7% grade. Wouldn't hold me back at my desired 55-60 in 6th. Wouldn't downshift. Lowered cruise setting to 40. Still wouldn't downshift. Just kept gaining speed till I manually put it in 5th

Mine does.

 

[mweiman]

Don't you have to push the exhaust brake button twice to put it into "smart brake mode"? I was thinking the purpose of that feature was to manage cruise speeds better.

 

[Powder Extreme]

I tried the exhaust brake in regular mode, smart mode, and off. The transmission will not downshift. It was in tow/haul.

 

[MelvinPierce]

Then take it back to the dealer. Although, after a couple million miles driving a peterbilt with a 13 speed, having to manually downshift a gear to get better exhaust braking is NOT a big deal! LOL

 

[Powder Extreme]

Lol. I hear ya, I drove many many miles in a Freightliner. Now I'm just being lazy!

I'm having several issues with the truck actually, this is just one more thing to add to the list.

 

[jgillott]

Lol. I hear ya, I drove many many miles in a Freightliner. Now I'm just being lazy!

I'm having several issues with the truck actually, this is just one more thing to add to the list.

If you don't mind, what other issues? I'm seriously considering replacing one of mine and I'd like to know what to look forward to.

 

[Wal_mart]

I thought tow haul mode locked out 6th gear.

 

[Wertles]

Nobody asks, how come it is in 6th gear in tow haul mode

That's how they are designed to tow. I'm turning 2000 rpm in 6th gear at 70 mph with my 4:10's. I almost think I could have gone with 3. 73's since I have so much available power available to me now. I barely shift into 5th when pulling my 18k pound 5th wheel. My old 48re would shift to 3rd fairly regularly pulling this load.

 

[Powder Extreme]

I thought tow haul mode locked out 6th gear.

Top gear hasn't been locked out in tow haul mode for years. Trannies are built to tow in top gear.

 

[Newt]

If you can't tow in the top gear on level ground, you need a lower rear end.

Newt

 

[Powder Extreme]

If you don't mind, what other issues? I'm seriously considering replacing one of mine and I'd like to know what to look forward to.

Stereo volume control doesn't work right and nav loses its position. Truck also has a surge a light throttle and the transmission will down shift, up shift, down shift, up shift when climbing with a light load on. (Yes in tow/haul mode)

 

[jgillott]

Stereo volume control doesn't work right and nav loses its position. Truck also has a surge a light throttle and the transmission will down shift, up shift, down shift, up shift when climbing with a light load on. (Yes in tow/haul mode)

Thanks. I appreciate it.

 

[MelvinPierce]

Stereo volume control doesn't work right and nav loses its position. Truck also has a surge a light throttle and the transmission will down shift, up shift, down shift, up shift when climbing with a light load on. (Yes in tow/haul mode)

There are times when you are just between two gears, and the transmission goes back and forth. Just manually shift down to the lower gear! Easy fix. Have the transmission reflash, and do a quick relearn. Seems to help.



Radio issues are another thing!

 

[Powder Extreme]

Did have the transmission reflashed and quick learn. Allison doesn't do that, picks a gear and stays there. But I guess Allison has been building truck trannies much longer and have the programming figured out. (For the most part)

And yes, I just manually drop it and stay there, but my point is with all the new computer controls on my nearly $70,000 pickup, I expect things to work properly. I shouldn't have to do "manual" workarounds to make it drive satisfactory.

Also, I'm certain there are probably more people driving these rigs that have never heard of the TDR and have no idea what the little switches do. Not too mention the all too often clueless salesmen that are no help at all in guiding the customer.

Those guys on the road with their 40' toyhaulers are the ones that scare me, it would be reassuring to know at least the truck is looking out for them, so to speak.

 

[MelvinPierce]

Did have the transmission reflashed and quick learn. Allison doesn't do that, picks a gear and stays there. But I guess Allison has been building truck trannies much longer and have the programming figured out. (For the most part)

And yes, I just manually drop it and stay there, but my point is with all the new computer controls on my nearly $70,000 pickup, I expect things to work properly. I shouldn't have to do "manual" workarounds to make it drive satisfactory.

Also, I'm certain there are probably more people driving these rigs that have never heard of the TDR and have no idea what the little switches do. Not too mention the all too often clueless salesmen that are no help at all in guiding the customer.

Those guys on the road with their 40' toyhaulers are the ones that scare me, it would be reassuring to know at least the truck is looking out for them, so to speak.

1. So, an Allison never shifts in response to load and grade changes? It just stays there? Sounds like you would be happier with an Allison.

2. I guess you are scared of me! LOL I have a 40' toyhauler. Not sure why that should scare you, but if it does, not much I can do about that! LOL

 

[Powder Extreme]

You missed what I said entirely. I said MOST people have never heard of the TDR. And sadly, there are a lot of people on the roads hauling or towing way more than they should be. As a former truck driver for awhile, I can say I've seen it way more times than I can count. I didnt say EVERY person towing didnt know what they were doing. I would guess that there are way more who don't then those of us who do.

And yes, the Allison will pick the gear it needs and stay there. It doesn't constantly up shift and down shift. I would assume the Aisin being a medium duty transmission would do the same thing.