Question for 4.88 guys with 35's

[Mountaineer83]

I'm anxiously awaiting your towing update. I'm still seriously considering a regear for towing. I'm not stock size tires, but really would like some more bottom end.

 

[IRSmart]

In my experience with my ‘16 power wagon, when in tow/haul mode the trans will never go into 6th gear. With my 8000 pound travel trailer it will rarely go into 5th unless its slight downhill grade. With light trailers it will hit 5th all the time, but I have never seen 6th in tow/haul. Even With light/moderate throttle on low downward slopes.

Um...that’s because tow/haul eliminates 6th year altogether, no matter what the driving conditions are...

 

[olyelr]

Um...that’s because tow/haul eliminates 6th year altogether, no matter what the driving conditions are...

Yea, thats what I figured. And Im sure it was designed that way for a reason. Thats why I was suggesting using tow/haul mode when towing heavy, so 6th gear would not be used.

 

[FlatbedHemi]

Um...that’s because tow/haul eliminates 6th year altogether, no matter what the driving conditions are...

I could have sworn that mine would shift into 6th in T/H when under light throttle cruising, usually around 55mph. Anything faster or on hilly terrain and it would pretty much stay in 5th, but I could swear that it would shift into 6th for long flat strips with my 16' trailer. Maybe Im mistaken though. Its been a while since my truck was stock. Been hauling this bed around for over 2 years.

 

[G. Mcpherson]

In Tow Haul at 60-61 mine shifts into 6th.

 

[olyelr]

Ive tried getting my truck to go into 6th gear with tow haul mode in the past. Even without a trailer it wouldn't do it. Maybe you have to be traveling the perfect speed? I just assumed it locks it out.

 

[U&A]

Just an FYI.

I ordered a ProCal from AEV and used it to set the 35 inch tire size and new gear ratio Of 4.88 in my Ram 3500. It made a big difference in the smoothness if shifting, shift points, and power delivery. ‘Noticeable immediately after using it, but even bigger improvement after driving the truck a couple days. I used the ProCal after driving the truck over 500 miles with the new gear change just to be sure the difference wasn’t just the truck learning how to drive once again with the gear change.

I’m sure whatever programmer you use that will set these parameters will work great. I just chose AEV as they seem to be a trustworthy company with good products. I haven’t tried any other unit.

How do you set this up for your specific tire size and gear ratio. I don’t see any buttons or screen on this when I look it up on AEV’s website


Sent while firmly grasping my redline lubed RAM [emoji231]

 

[IRSmart]

I could have sworn that mine would shift into 6th in T/H when under light throttle cruising, usually around 55mph. Anything faster or on hilly terrain and it would pretty much stay in 5th, but I could swear that it would shift into 6th for long flat strips with my 16' trailer. Maybe Im mistaken though. Its been a while since my truck was stock. Been hauling this bed around for over 2 years.

Nope, tow haul eliminates 6th gear completely.

 

[Iron Outlaw]

Mine dont go into 6th with tow haul on.

 

[olyelr]

How do you set this up for your specific tire size and gear ratio. I don’t see any buttons or screen on this when I look it up on AEV’s website


Sent while firmly grasping my redline lubed RAM [emoji231]

By using some dip switches on back side.

 

[G. Mcpherson]

Tow haul does not lock out 6th gear. Some trucks will need to go at least 65 or so. I am talking about Diesel trucks. Mine definitely shifts to 6th in Tow Haul. I can lock it out when needed as so can the 66RFE.

 

[IRSmart]

Tow haul does not lock out 6th gear. Some trucks will need to go at least 65 or so. I am talking about Diesel trucks. Mine definitely shifts to 6th in Tow Haul. I can lock it out when needed as so can the 66RFE.

Yes it does. It is specifically mentioned as one of the features of tow/haul. Overdrive is eliminated when tow/haul is engaged. 1500-5500, it doesn’t matter.

 

[Iron Outlaw]

It must be a 6.7 vs 6.4 thing. Or maybe it changed for a few year models, Cause I can run 85 in tow haul and it wont go past 5th. I think my old 2009 6.7 would in fact go into 6th though.

 

[G. Mcpherson]

Yes it does. It is specifically mentioned as one of the features of tow/haul. Overdrive is eliminated when tow/haul is engaged. 1500-5500, it doesn’t matter.

Would it be possible for you to point me in the direction of your information regarding this. From what I have been reading it is different from your thoughts. There are a few comments on the Cummins Forum stating otherwise. Also my Truck most definitely makes a shift with a lower RPM at 61 mph. Thanks

 

[IRSmart]

Would it be possible for you to point me in the direction of your information regarding this. From what I have been reading it is different from your thoughts. There are a few comments on the Cummins Forum stating otherwise. Also my Truck most definitely makes a shift with a lower RPM at 61 mph. Thanks

Overdrive will not activate with the TH mode on. Get your truck up to speed, then hit the down arrow on the ERS selector and I’ll bet you a bar tab your gauge cluster says 5, not 6. Others suggesting the truck will go into 6th in TH mode are incorrect. It’s a feature that is fundamental to the system of TH. It is designed to help eliminate fear hunting, and one way of doing that is to eliminate overdrive from the shift mapping. Trust me, I know what I’m talking about



What you’re likely experiencing with the RPM drop is the torque converter clutch engaging and disengaging. Not an actual gear.

 

[olyelr]

Yea, simply place the the gear selector in sixth, and it will tell you what gear its in.

 

[G. Mcpherson]

Found this on the Allpar site. A “Tow/Haul” mode allowed faster, crisper shifts, to reduce wear. Under partial throttle, shifting into gears above third was delayed; and the system was likely to kick down under part throttle into fourth and fifth. The Tow/Haul mode still allowed overdrive unless the driver locked it out

 

[Iron Outlaw]

I tested mine this morning. Was doing 80 in 5th gear, no trailer with tow haul on. It would only go into 6th when I would hit tow haul off. It would down shift when I turned it back on.

 

[Big Terry]

Nope, tow haul eliminates 6th gear completely.

********. Absolute ********. I don't know where you came up with this nonsense but it absolutely does not lock out 6th gear, either with or without a trailer connected.

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[FlatbedHemi]

********. Absolute ********. I don't know where you came up with this nonsense but it absolutely does not lock out 6th gear, either with or without a trailer connected.

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Dude, you drive a diesel. That's probably the difference.