Tow mode or not ?

[John Jensen]

2021 3500 with the HO engine and Aisin tranny. Fixing to start pulling a 5th wheel (13K dry weight). I think yow/haul is a given, but what about the exhaust brake, on all the time or only when going downhill on long grades?

I run EB 100% of the time. Empty, in town, on the road, pulling my trailer. I change between full and auto according to conditions. Probably in auto 95% of the time. Use full when driving local. Saves brake wear and tear.

Know that EB is more aggressive when in TH.

EDIT:
Note that your Aisin will not disable or drop a gear. TH, EB, or whatever setting you are set at the Aisin will always use all 6 gears. IMO a great tranny!

 

[turkeybird56]

2019 RAM 1500 Rebel 5.7l Hemi. Tow mode disables 8th gear for me and limits to 7th. Only ever use tow mode when towing so I don't know if it disables 8th when a trailer is not attached. I will try.

Hmmmmm, I dunno ref lockout of 8th, I also have a 19 DT Truck. My only thought would be tranny programmed different due to Rebel Trim, but I kinda think hmmmm on that. Gonna have to drive my truck with Tow Mode on to see if it locks out 8th, but honestly I think it does not, trans just not getting up to the shift point with the towing/weight. Empty, no towing in tow mode all gears should engage. ALL THIS IMHO... only ... I will post back tomorrow, 26 July on 8th gear, as I have to go to town ne way, not wanna make an extra trip just to check on a setting, hee hee, especially at the price of fuel.

OK: UPDATE: Ran around with Tow Haul on yesterday, 27 July. On MY 19 DT truck, 5.7L, no E junk, 3:21, Tow Haul does not Lock out my 8th gear. Bit since it does change shift points, you have to be going a lil faster and more level for 8th gear to kick in and stay there.

 

[Dfleck65]

2021 3500 with the HO engine and Aisin tranny. Fixing to start pulling a 5th wheel (13K dry weight). I think yow/haul is a given, but what about the exhaust brake, on all the time or only when going downhill on long grades?

I too have 2021 3500 HO and 14.5k 5er and use tow/haul always when towing. The exhaust break is also always on auto. The mountains here in CO can wear brakes and using the exhaust break minimizes how often I have to even touch my breaks on descent.

Heading to Ridgeway on weds and love driving my RAM, makes mountain driving with a large RV enjoyable!

 

[crash68]

I think yow/haul is a given, but what about the exhaust brake, on all the time or only when going downhill on long grades?

When towing use the exhaust brake all the time. The Full setting will "apply" the EB any time you let off the accelerator pedal. The Auto settings applies the EB when you use the vehicle brakes. If you use the cruise control with either EB mode, it will automatically apply to keep the truck at the set cruise speed. Work really well even if adjusting the speed on the fly using the buttons.
Only time it's probably not a good idea to use the EB is on snow/ice slick road conditions.

 

[RoosterR]

Hi,

I have a '22 3500 w/the aisin trans w/tow package. I pull a 12K 5th wheel.

Hauled my 5th on a 10 hour trip last week. Cannot decide if I should be using tow mode or not. It seems to rev about 500 rpm higher in tow mode but I don't see or feel much of a difference other than that.

My sales rep was non comitial.

I am heading off for a 11k mile trip in November..

Any thought ? Would appreciate input.

Thanks, ian.

I pull a 42 foot Fifth wheel 14,000 lbs. I always use tow haul and exhaust brake together. The tow haul changers the shift points and that’s why you are getting higher RPM’s.

 

[78Staff]

As a member posted in another thread of similar subject... "If it's on the Ball, put it in Haul..."

 

[Dusty]

This thread is somewhat confusing because it has comments related to the 1500, 2500, and 3500 (Aisin) transmissions. There are operational differences between them.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 74797 miles

 

[jejb]

This thread is somewhat confusing because it has comments related to the 1500, 2500, and 3500 (Aisin) transmissions. There are operational differences between them.

True, it has wandered off subject here and there. But the OP is specific that it's an HO Cummins HD truck.

 

[JayLeonard]

2021 3500 with the HO engine and Aisin tranny. Fixing to start pulling a 5th wheel (13K dry weight). I think yow/haul is a given, but what about the exhaust brake, on all the time or only when going downhill on long grades?

I have the SO Cummins and tow a bumper pull of about 7k lbs. I have the exhaust brake on smart mode all the time when towing. That way I don’t have to think about it and reach for the switch if the situation gets hairy. Plus it keeps the truck from accelerating going down hill on the expressway.

 

[Dannycameo]

I have an HO with the Aisin.
FYI - no gear is locked out while in tow haul.

I can only speak for the 8 speed, not the 6.
In Tow haul mode it will not go into 8th so that is true on the 8 speed anyway. Even going down a hill.
I have a 2022 power wagon, and I can tell you when I tow, in tow haul mode it will not go into 8th, if I take tow haul mode off, it will go into 8th. This is on flat Is prairie highway.
This is true of every vehicle I've had that's that's had a tow haul mode. Tow haul mode will keep it out of overdrive.
From grand Cherokees with the tow package, To ram trucks.

 

[06 Dodge]

2021 3500 with the HO engine and Aisin tranny. Fixing to start pulling a 5th wheel (13K dry weight). I think yow/haul is a given, but what about the exhaust brake, on all the time or only when going downhill on long grades?

IMHO towing 13K its a must to have exhaust brake on full all times truck is moving, when I'm not towing I put it on auto it allows you to to coast & it also helps slow down without using my brakes and its there when some fool stops suddenly in from of me...

 

[crash68]

I have a 2022 power wagon, and I can tell you when I tow, in tow haul mode it will not go into 8th, if I take tow haul mode off, it will go into 8th. This is on flat Is prairie highway.
This is true of every vehicle I've had that's that's had a tow haul mode. Tow haul mode will keep it out of overdrive.

Both 7th & 8th in the ZF8 spds are overdrive gears.
Not all transmissions lock out the last gear with the Tow/Haul mode on, I've had my EcoDiesel go into 8th many times with Tow/Haul on.
It would be interesting to try running the 8HP75 in the HD trucks up to about 90-95 mph with the Tow/Haul mode on to see if it will shift to 8th.
Transmission controllers are smarts, they can hold out gears based on a probable torque range of the gear. It will calculate how much torque is conceivably available from a gear and doesn't allow an upshift until a threshold is met.

 

[crash68]

I have an HO with the Aisin.
FYI - no gear is locked out while in tow haul.

Just this past weekend pulling a solid 9K lbs trailer up a 3% grade behind a '22 CTD HO. In 6th gear about 7lbs of boost on the flat and it peaked about 25 psi on the way up 6th gear the whole way. The speedo dropped to 69 briefly(cruise set @ 70).

 

[John Jensen]

I can only speak for the 8 speed, not the 6.
In Tow haul mode it will not go into 8th so that is true on the 8 speed anyway. Even going down a hill.
I have a 2022 power wagon, and I can tell you when I tow, in tow haul mode it will not go into 8th, if I take tow haul mode off, it will go into 8th. This is on flat Is prairie highway.
This is true of every vehicle I've had that's that's had a tow haul mode. Tow haul mode will keep it out of overdrive.
From grand Cherokees with the tow package, To ram trucks.

Interesting. My Eco 8 speed will run in the 8th gear while in TH.

 

[KKBB]

I can only speak for the 8 speed, not the 6.
In Tow haul mode it will not go into 8th so that is true on the 8 speed anyway. Even going down a hill.
I have a 2022 power wagon, and I can tell you when I tow, in tow haul mode it will not go into 8th, if I take tow haul mode off, it will go into 8th. This is on flat Is prairie highway.
This is true of every vehicle I've had that's that's had a tow haul mode. Tow haul mode will keep it out of overdrive.
From grand Cherokees with the tow package, To ram trucks.

I have a 2019 2500 with the 6.4 hemi and mine will go into 8th with tow haul mode on. It has only done it twice, but it has done it. The first time it did, I was shocked. Had to double check that I was in tow haul mode...I was. I was going roughly 62-65 mph towing our 11k fifth wheel on a probably 2 or 3% downhill grade when it happened. I think it has to be absolutely perfect in order for it to happen. It downshifted back to 7th even before I hit perfectly flat ground.

 

[N2MoPar]

Hi,

I have a '22 3500 w/the aisin trans w/tow package. I pull a 12K 5th wheel.

Hauled my 5th on a 10 hour trip last week. Cannot decide if I should be using tow mode or not. It seems to rev about 500 rpm higher in tow mode but I don't see or feel much of a difference other than that.

My sales rep was non comitial.

I am heading off for a 11k mile trip in November..

Any thought ? Would appreciate input.

Thanks, ian.

Tow/Haul reprograms the trans to hold it in gear longer so it will use the engine's powerband closer to peak under load. And yes, the RPM will go up 500 or so depending on your load.
Also, on a 1500, if you are going downhill and are picking up speed, just tap the brakes and it will downshift 1 gear slowing you down without riding the brakes.
Not sure if it's the same in a 2500 or 3500 but I would think it is.

I use it whenever I'm pulling my travel trailer (about 4,840 lbs dry).
I don't recall it ever getting to 8th gear though. Could be wrong on that though.

 

[Bearcatrp]

My 3500 will downshift if I tap on the brakes going down hill. I always use tow haul mode when towing.

 

[Riccochet]

My 2500 6.4 with the ZF8 will go in to 8th with T/H on. Even while towing an 8000# travel trailer.

 

[KKBB]

This isn't the greatest pic, but it shows tow/haul mode and it is in 8th. Happened a few different times yesterday when bringing our 5th wheel to the campsite.

 

[KKBB]

It doesn't show its in tow/haul unless you click on the pic above to see the full pic.