Tow/haul mode always when towing?

[Darksteel165]

i down shift manually and up shift manually all the time

You can't up-shift manually on a 22 bighorn unless you changed the stock firmware on your TCM, but okay.

 

[theblet]

You can't up-shift manually on a 22 bighorn unless you changed the stock firmware on your TCM, but okay.

If the stock ecu won’t let you upshift to a gear, that should mean that you wouldn’t be able to use it anyway. Say you're doing 30 miles an hour, and you were able to upshift to 8th gear, that wouldn’t work to well.

 

[Rick3478]

You can't up-shift manually on a 22 bighorn unless you changed the stock firmware on your TCM, but okay.

That begs the questions: CAN you change the TCM firmware to get a manual shift mode, and if so what does that entail?

So everyone acts like it's not a big deal, but here's my experience. I have occasion to travel through northern Indiana from time to time, and the land there is overall level, but has a lot of small up and down, "swales" if you will. If I try to use cruise, the transmission is constantly shifting up and down trying to maintain a constant speed. It's irritating and unnecessary and can't be good for the transmission. Tow/Haul
does it too, just at higher engine speed.

Maybe the real problem is too much gain in the cruise control system. I wouldn't care if speed dropped by a couple MPH and then sped back up a couple after cresting a hill, but no the cruise insists on maintaining an exact speed.

But if I could tell it to stay in 6, for example, I wouldn't care if the throttle went wide open for a couple seconds climbing and near idle after cresting a hill, as long as engine speed is near optimum. I would still expect the torque converter to unlock if engine speed got low, but that's just to protect the engine, and not something I would do on a regular basis.

My current workaround is to turn off the cruise and feather the accelerator so it doesn't feel a need to shift, and of course this increases driver fatigue.

That's where I'm coming from, relative to Tow/Haul/Shifting.

 

[bigdodge]

You can't up-shift manually on a 22 bighorn unless you changed the stock firmware on your TCM, but okay.

really!

I do it all the time
and it is bone stock

 

[HSKR R/T]

That begs the questions: CAN you change the TCM firmware to get a manual shift mode, and if so what does that entail?

So everyone acts like it's not a big deal, but here's my experience. I have occasion to travel through northern Indiana from time to time, and the land there is overall level, but has a lot of small up and down, "swales" if you will. If I try to use cruise, the transmission is constantly shifting up and down trying to maintain a constant speed. It's irritating and unnecessary and can't be good for the transmission. Tow/Haul
does it too, just at higher engine speed.

Maybe the real problem is too much gain in the cruise control system. I wouldn't care if speed dropped by a couple MPH and then sped back up a couple after cresting a hill, but no the cruise insists on maintaining an exact speed.

But if I could tell it to stay in 6, for example, I wouldn't care if the throttle went wide open for a couple seconds climbing and near idle after cresting a hill, as long as engine speed is near optimum. I would still expect the torque converter to unlock if engine speed got low, but that's just to protect the engine, and not something I would do on a regular basis.

My current workaround is to turn off the cruise and feather the accelerator so it doesn't feel a need to shift, and of course this increases driver fatigue.

That's where I'm coming from, relative to Tow/Haul/Shifting.

I live in Nebraska with similar landscape. Maybe slightly larger hills. I can just use gear limiter to keep it from upshifting to higher gear going downhill and have no issues. Few weeks ago I towed fairly heavy (over 5k lbs) and on 65 mph roads set far limiter to 6th and had no issue. Only in the larger hills did it ever downshift to 5thz and it would have done that just using my foot as well

 

[Richard320]

really!

I do it all the time
and it is bone stock

So you can cruise down a residential street at 20 mph and upshift to 8 and lug the engine?

 

[Quint]

I think that he was confusing up-shifting and down-shifting. My 2021 Bighorn certainly will let me downshift into 1st if I want, but when I set it to a higher gear it will only upshift when it's gosh darn ready (i.e. I am at the correct speed and throttle value).

 

[Darksteel165]

That begs the questions: CAN you change the TCM firmware to get a manual shift mode, and if so what does that entail?

Yes

really!

I do it all the time
and it is bone stock

Have some picture as proof?
You can't force an upshift with a stock Bighorn without the above.

I think that he was confusing up-shifting and down-shifting. My 2021 Bighorn certainly will let me downshift into 1st if I want, but when I set it to a higher gear it will only upshift when it's gosh darn ready (i.e. I am at the correct speed and throttle value).

I don't think he's confusing it I think he's just begin hard to deal with. How can someone not understand putting the gear limit in 8 doesn't force it to upshift into 8 unless you never even tried it.

 

[Rick3478]

I think that he was confusing up-shifting and down-shifting. My 2021 Bighorn certainly will let me downshift into 1st if I want, but when I set it to a higher gear it will only upshift when it's gosh darn ready (i.e. I am at the correct speed and throttle value).

Yeah, you can "let it" upshift or "make it" downshift, up to a point.

 

[silver billet]

really!

I do it all the time
and it is bone stock

Our trucks have a gear limiter only. If you set it to "6", the truck will pick the best gear between 1 and 6. If you set it to 8, the truck will pick a gear between 1 and 8. You're limiting (hence the name) the top gear that the truck can use but other than that it still decides which gear is best within the range you've selected.

A manual shift is subtly different. You can force it to upshift and stay in that gear. I've never driven one with a manual gear, but I assume the truck lets you get into more trouble and as long as you wouldn't blow anything or stall the truck it will stay in whatever gear you pick.

However our trucks are programmed so well and the ZF is so amazing, I really don't see the point in a manual shift in these trucks. Pretty much ever time the truck picks a gear, I'd have preferred that gear as well. The only time I use it is while towing because even with T/H enabled it will upshift to 7'th more often than I like, my preference while towing is to keep it revving in the power band which for me is 2000+ RPMs.

 

[theblet]

Yeah, you can "let it" upshift or "make it" downshift, up to a point.

Wouldn’t it just upshift when appropriate, there no need to do it manually?

 

[biohazard]

Maybe the real problem is too much gain in the cruise control system. I wouldn't care if speed dropped by a couple MPH and then sped back up a couple after cresting a hill, but no the cruise insists on maintaining an exact speed.

I'm the opposite -- I get annoyed when the speed drops a few mph, because when that happens in other cars, the transmission might downshift 2 gears so that it can get back to speed. That's because by the time the downshift happens, your speed is now 5 mph too slow (and dropping), and now it is really off the pace. Of course, you probably have crested the hill by then, so it might overshoot the target speed and it will need to slow down.
Trust me, having the cruise stay on target is much better.

 

[Rick3478]

I'm the opposite -- I get annoyed when the speed drops a few mph, because when that happens in other cars, the transmission might downshift 2 gears so that it can get back to speed. That's because by the time the downshift happens, your speed is now 5 mph too slow (and dropping), and now it is really off the pace. Of course, you probably have crested the hill by then, so it might overshoot the target speed and it will need to slow down.
Trust me, having the cruise stay on target is much better.

Missing the point. In that scenario it didn't need to shift at all.

 

[Rick3478]

Wouldn’t it just upshift when appropriate, there no need to do it manually?

Just describing how it works, for those who want to use it, in response to someone else's post. These threads can get confusing. There are practical reasons, like you might want to keep it in 6 (direct drive) for a stiff pull to minimize wear on the transmission's overdrive gearsets, or maybe downshift to use engine braking.

The ZF transmissions for the most part do a good compromise job, and these additional user controls let the driver adjust it even better.

 

[theblet]

I also notice that having 8 gears, it shifts alot more often than another truck I use with 4 or 5 gears, but also not as much as a trans with 10 gears.

 

[Rick3478]

I also notice that having 8 gears, it shifts alot more often than another truck I use with 4 or 5 gears, but also not as much as a trans with 10 gears.

Yes it does. In theory at least, the extra gears add a bit of efficiency and performance by allowing a more optimum engine speed match. But it spends more time shifting, which I would think has to have a negative impact on those. And of course more parts means more opportunity for profit by the maker. I thought 5 or 6 gears was plenty, myself. Heck, my old Cheyenne only had 3, made power the old fashioned way by burning fuel at a high rate with a spread-bore 4-barrel carb, dual exhaust, and 4.10 gears. Progress, I guess.

 

[bigdodge]

So you can cruise down a residential street at 20 mph and upshift to 8 and lug the engine?

is this what you all mean? why would anyone do that
i use it to rev up the engine and to use the engine to hold it back on hills, if it goes above 5k i just put it in the next gear.

 

[theblet]

is this what you all mean? why would anyone do that
i use it to rev up the engine and to use the engine to hold it back on hills, if it goes above 5k i just put it in the next gear.

Yes, they thought u were pretending to have a manual

 

[Richard320]

is this what you all mean? why would anyone do that
i use it to rev up the engine and to use the engine to hold it back on hills, if it goes above 5k i just put it in the next gear.

We were hoping you could tell us, because you insisted you can manual upshift.

 

[biohazard]

Missing the point. In that scenario it didn't need to shift at all.

No, I got your point. You didn't get mine because you're not thinking things through.
Cruise control is reactive, and it also cannot predict when dropping a few mph is ok or not. I would prefer to have it stay at the exact speed, rather than drop too much speed and then try to catch up.