[micksbuddy]

I'm going to go test drive a '14 3500 68rfe 3.42 in the next couple of days, but I will not be able to hook a load to it for the test drive. My question is would the truck stay in 6th pulling 10-15k lbs on moderate hills? I had an '01 2500 nv5600 that you could just put it in 6th, set the cruise and go with no problems. I currently have a 6.0 powerstroke with the 5R110 that will downshift or unlock the torque converter on even slight hills on the interstate with 12k behind it, which I find annoying. So I'm curious if I switch back to a cummins w/68rfe if it will cruise on the interstate with that kind of load and be able to hold 6th.

 

[BFD]

My 12 holds 6th TOO good!

 

[Lins]

My 12 holds 6th TOO good!

Agreed. 5th puts it in a better power band depending on speed. Not sure why the OP would find that annoying.

 

[coolbreeze]

Lower gears as needed on hills is better for the engine and transmission.

 

[98whitelightnin]

My 12 holds 6th TOO good!

And your 12 with 3.73 will definitely out pull that 14 in 6th. OP, if it does shift, it will drop a gear and then directly lock back up. That 14 will also have tow/haul mode that will hold out gears longer and will keep you from going into 6th all together, if you’re under a certain speed. You will also be able to lock out 5th or 6th. My truck will not go into 6th until 71 or so, if I’m in tow/haul.

 

[Murphjd25]

My 14 will shift into 6th and stay there up hills also. But I lock out 6th, and let it eat in 5th at 2000 rpm, she’s happy then.

 

[Scott_Cummins_Newbe]

6th is a small clutch pack (overdrive). If it was my personal truck I always do hills in 5th or 4th (direct drive). Not a fan of towing weight using cruse control, especially in mountainous terrain.

 

[Lins]

Not a fan of towing weight using cruse control, especially in mountainous terrain.

I do it all the time, including over the Rockies. Exhaust brake on full, cruise control and manually locking out gears as/if needed.

 

[mattswaggs]

I do it all the time, including over the Rockies. Exhaust brake on full, cruise control and manually locking out gears as/if needed.

This ugly Chevy being my first auto in a long time, that’s how I drive…. But… for an auto, I really like Allison. She’s nice.

 

[micksbuddy]

Agreed. 5th puts it in a better power band depending on speed. Not sure why the OP would find that annoying.

As I said in my post, I find it annoying that my current truck(a 6.0powerstroke/5R110 combo) will downshift or unlock the torque converter on even slight inclines when pulling 12k, which takes it from 2000rpm to 2700rpm, when I'm used to(and think a turbo diesel should be able to) the truck holding a gear, building boost and pulling the grade. I wouldn't expect it to pull steep grades in top gear, or if it was falling off the torque curve, then clearly a downshift is in order. But on modest hills I would prefer the truck to simply stay in gear, build the necessary boost and continue on down the road.

I'm simply interested in getting some feedback on whether the 350/800 Cummins 68rfe combination will hold the selected gear(whether 5th or 6th if reasonable) in rolling terrain.

 

[mattswaggs]

As I said in my post, I find it annoying that my current truck(a 6.0powerstroke/5R110 combo) will downshift or unlock the torque converter on even slight inclines when pulling 12k, which takes it from 2000rpm to 2700rpm, when I'm used to(and think a turbo diesel should be able to) the truck holding a gear, building boost and pulling the grade. I wouldn't expect it to pull steep grades in top gear, or if it was falling off the torque curve, then clearly a downshift is in order. But on modest hills I would prefer the truck to simply stay in gear, build the necessary boost and continue on down the road.

I'm simply interested in getting some feedback on whether the 350/800 Cummins 68rfe combination will hold the selected gear(whether 5th or 6th if reasonable) in rolling terrain.

I can’t tell you about the 68, but this Chevy will hold 6th at 1,650 rpm pulling a 14k 5th wheel up most hills. But like others mentioned, I usually hit 5th gear for hills. My 5th is .71 whereas the 68re is .81, so it’s a bigger jump in rpm in the ram. I think the ram has more low end grunt and can’t imagine it downshifts like the ford 5r

 

[H3LZSN1P3R]

As I said in my post, I find it annoying that my current truck(a 6.0powerstroke/5R110 combo) will downshift or unlock the torque converter on even slight inclines when pulling 12k, which takes it from 2000rpm to 2700rpm, when I'm used to(and think a turbo diesel should be able to) the truck holding a gear, building boost and pulling the grade. I wouldn't expect it to pull steep grades in top gear, or if it was falling off the torque curve, then clearly a downshift is in order. But on modest hills I would prefer the truck to simply stay in gear, build the necessary boost and continue on down the road.

I'm simply interested in getting some feedback on whether the 350/800 Cummins 68rfe combination will hold the selected gear(whether 5th or 6th if reasonable) in rolling terrain.

Yes it will. Aslong as you dont go throwing bigger tires on it with the already sad 3.42 gears it has

 

[grimreapor6969]

I have the 68rfe in my 08 and and haul dump trailers I average 28k gross and I can set the cruise at 70 and it stays in 6th in tow/haul mode weather an overpass or the Buckman bridge in Jacksonville, FL the only thing that happens is you hear and see the boost climb but it won't even loose 1 mph.

 

[mattswaggs]

I have the 68rfe in my 08 and and haul dump trailers I average 28k gross and I can set the cruise at 70 and it stays in 6th in tow/haul mode weather an overpass or the Buckman bridge in Jacksonville, FL the only thing that happens is you hear and see the boost climb but it won't even loose 1 mph.

That was my experience with my 2013 g56, obviously wouldn’t downshift, but boost would climb a little but never lose speed. That was a good truck.

 

[Murphjd25]

The 68rfe will stay in 6th. Last time we took the trailer out I forgot to lock out 6th and we went over some pretty steep passes. Stayed in 6th at 70 and just built boost. I had to get off it because I was running around 34 lbs of boost towards the top lol(egts)

 

[grimreapor6969]

That was my experience with my 2013 g56, obviously wouldn’t downshift, but boost would climb a little but never lose speed. That was a good truck.

Oh I know the feeling I love my 08, I have a 21 3500 4x4 DRW too and prefer the 08 hands down. She out does the 21 every which way, plus having 7" of lift and 37's she's a lot more fun to drive lol

 

[mattswaggs]

Oh I know the feeling I love my 08, I have a 21 3500 4x4 DRW too and prefer the 08 hands down. She out does the 21 every which way, plus having 7" of lift and 37's she's a lot more fun to drive lol

Our vehicles are a 99, 2015, 2017 and 2018.
When it comes time to upgrade to more reliable, better performing vehicles, that will mean we will buy ones older than our currents.

 

[Murphjd25]

Our vehicles are a 99, 2015, 2017 and 2018.
When it comes time to upgrade to more reliable, better performing vehicles, that will mean we will buy ones older than our currents.

That’s a shame isn’t it. I was going to buy a brand new fancy truck too but I wanted reliability over everything else, and where I landed is where I landed with a 14.

 

[BFD]

To save the trans, I purposely reduced my tq so it really drops off below 1800. I have to drop to 5th with the button otherwise it won’t downshift by itself. I like it that way. It’s a monster above1800!

 

[micksbuddy]

I appreciate everyones input. This truck didn't work out, but I'll be keeping an eye out for the next candidate.