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Discussion Starter #1
First time towing over steep grades (Saluda NC). Just want to make sure I do it correctly. Obviously I will be using T/H function. Just wandering if I need to manually drop down to 3 or stay in D when approaching the "steepness"?? Or can I stay in D, and let the AT do it's thing? Total weight is no more than 8k lbs. Thanks in advance!!
 

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Usually I just let it do it’s thing. If it wants to lug going up a hill, click it down a gear. I like my RPMs between 1800-2200 to keep everything cool, and stay in the torque band. If you do decide to select gears manually going up a hill, make sure to put it back into drive when you start back down. If you are manually selecting gears, the transmission is no longer able to act on its own to utilize trans braking, and the exhaust brake.


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Discussion Starter #3
Usually I just let it do it’s thing. If it wants to lug going up a hill, click it down a gear. I like my RPMs between 1800-2200 to keep everything cool, and stay in the torque band. If you do decide to select gears manually going up a hill, make sure to put it back into drive when you start back down. If you are manually selecting gears, the transmission is no longer able to act on its own to utilize trans braking, and the exhaust brake.
Thanks, so the trans braking only works in D? I didnt know the LLY had an exhaust brake but maybe that was part of the VGT? Anyway, thanks for the advice.
 

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Sorry, didn’t notice what you had. Yeah, no exhaust brake unless you wired one in. Correct, trans will work best downhill in drive...


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Several things:
1) You mentioned D and 3. How about simply locking out D, which gives you gears 1-4? To lock out D, simply press and hold the T/H button for several seconds until the slashed-D shows up on the display.
2) T/H will hold the gears longer on upshifts, and more aggressively downshift when braking. With the trailer, use T/H for sure.
3) You can use both T/H and locked-out D at the same time. It will still have the T/H characteristics, but it just won't go into 5th gear.

If going uphill, adjust your speed so the engine is 2200-2500 rpm. You may manually adjust the higher gear lockout (D=1-5, locked out D is 1-4, shifting to "3" is 1-3, etc.) as needed.

Since it's an LLY, watch your engine temps and know that if the dash gauge goes up one notch, you're at 220*F (most will show 210*F on the gauge at that point). You'll have to decide how hot you let it get. I'm a weenie so I don't like over 220*F, but then I have an aux radiator so it doesn't happen, and so far I still have the original headgaskets (but opinions vary).
 

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How steep are the grades there?
 

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Not "Rocky Mountain" steep or much altitude either... :wink2:
I don't know never been east. Spent some time west. Most I can pull in 4th with a 14K 5th wheel.
 

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THRS aug 01 '19
================================================
Mine is a '13 3500. Either of our two trailers weighs around 11,000 lbs. (bumper-pull).

I live in northern Arizona - make frequent trips to Las Vegas and Los Angeles. Passes here are over 6,000 ft., "Kingman Grade" drops you down to the bridges across the Colorado River - elev. about 600 ft. above sea level. C'mon guy....the "mountains" in your area.. we wouldn't give them the status of ant-hills out here..!

You would be well-advised to remember Clint Eastwood's famous expression "man's got to know his limitations". You think you are smarter than Allison engineers? Well...I paid for their talents, like what they have come up with.

Leaving it in tow-mode insures the more positive "lock-ups" and better rpm control will be easier on both you and your truck.

One qualification. On long level stretchs (yeah...there are some out here...few and far between....!) because I like to cruise no faster than 65., I find in tow-mode it wont go into the top overdrive. I solve that by momentarily taking it out of tow mode, so that it will shift into the highest overdrive. Since that is a "lock up" it dosnt risk hurting anything. That gives me around 1,600 rpm - good economical speed. Sure, the engine can spin faster safely, but the simple fact of physics is the slower you spin the motor, less friction loss.
 

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First time towing over steep grades (Saluda NC). Just want to make sure I do it correctly. Obviously I will be using T/H function. Just wandering if I need to manually drop down to 3 or stay in D when approaching the "steepness"?? Or can I stay in D, and let the AT do it's thing? Total weight is no more than 8k lbs. Thanks in advance!!
Looks like you got some good advice on how to handle the truck, but the one thing I didn't see mentioned is the trailer. Definitely a good time to really check the trailer brakes, and without an exhaust brake you'll be relying on the service brakes to dissipate energy coming down those hills. If your trailer brakes aren't handling their share of the energy dissipation you stand a significant chance of overheating the truck's brakes.
 

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THRS aug 01 '19
================================================
Mine is a '13 3500. Either of our two trailers weighs around 11,000 lbs. (bumper-pull).

I live in northern Arizona - make frequent trips to Las Vegas and Los Angeles. Passes here are over 6,000 ft., "Kingman Grade" drops you down to the bridges across the Colorado River - elev. about 600 ft. above sea level. C'mon guy....the "mountains" in your area.. we wouldn't give them the status of ant-hills out here..!

You would be well-advised to remember Clint Eastwood's famous expression "man's got to know his limitations". You think you are smarter than Allison engineers? Well...I paid for their talents, like what they have come up with.

Leaving it in tow-mode insures the more positive "lock-ups" and better rpm control will be easier on both you and your truck.

One qualification. On long level stretchs (yeah...there are some out here...few and far between....!) because I like to cruise no faster than 65., I find in tow-mode it wont go into the top overdrive. I solve that by momentarily taking it out of tow mode, so that it will shift into the highest overdrive. Since that is a "lock up" it dosnt risk hurting anything. That gives me around 1,600 rpm - good economical speed. Sure, the engine can spin faster safely, but the simple fact of physics is the slower you spin the motor, less friction loss.
Agreed!
 

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I'll add this if you are unsure of what's at the bottom of the hill go down slowly.
I went down Monarch pass in Colorado, I maintained between 25-30 mph in 2nd gear W/O exhaust brake & I had some hot brakes by the time I got down. That was with my 14K 5th wheel.
 
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Well.. here in Colorado we have mountains. Where he'll be towing.. well them are just ant hills compared to the Rockies.
 

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Discussion Starter #16
Several things:
1) You mentioned D and 3. How about simply locking out D, which gives you gears 1-4? To lock out D, simply press and hold the T/H button for several seconds until the slashed-D shows up on the display.
2) T/H will hold the gears longer on upshifts, and more aggressively downshift when braking. With the trailer, use T/H for sure.
3) You can use both T/H and locked-out D at the same time. It will still have the T/H characteristics, but it just won't go into 5th gear.

If going uphill, adjust your speed so the engine is 2200-2500 rpm. You may manually adjust the higher gear lockout (D=1-5, locked out D is 1-4, shifting to "3" is 1-3, etc.) as needed.

Since it's an LLY, watch your engine temps and know that if the dash gauge goes up one notch, you're at 220*F (most will show 210*F on the gauge at that point). You'll have to decide how hot you let it get. I'm a weenie so I don't like over 220*F, but then I have an aux radiator so it doesn't happen, and so far I still have the original headgaskets (but opinions vary).
Man thanks a ton for this. I had no idea about disabling 5th. Wish ida read this before now lol. Well anyway we made it fine. Only one issue was when I started up the steepest grade, the ect got to 220 and my edge started alarming. What’s weird is the whole trip up until then, the clutch fan would engage around 210. But it didn’t engage up the grade till 225-230. Temps came back down thankfully but I was worried there for a sec.
 

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Discussion Starter #17
Well.. here in Colorado we have mountains. Where he'll be towing.. well them are just ant hills compared to the Rockies.
Well these here ant hills are steep enough for me and my 2500 so that’s why I reached out for advice. No matter one’s terrain or situation, it’s great to be part of a forum that’s willing to jump in and help a dude out. So, even though you live close to the “real hills”, I appreciate your advice on how to navigate our little bumps in the road.
 

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Discussion Starter #18
Thanks to all who helped me out here!
 

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Well these here ant hills are steep enough for me and my 2500 so that’s why I reached out for advice. No matter one’s terrain or situation, it’s great to be part of a forum that’s willing to jump in and help a dude out. So, even though you live close to the “real hills”, I appreciate your advice on how to navigate our little bumps in the road.
Ignore the bullshit. I've pulled my relatively small trailer (about 10k) back and forth across the continent and there are plenty of little "ant hills" here in NJ/NY (try route 23 up by High Point, NJ or 23A east of Tannersville, NY) that are just as challenging to descend safely as the big mountains out west.

And if I recall correctly, you're in NC...I doubt anyone would call Mount Mitchell an ant hill. ;)
 
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