Manually down shifting automatic trans on hills?

[Little Red]

Is it bad to downshift to either 3rd or 2nd gear (pending speed, road condition, etc.) to use the engine compression to safely maintain speed and control my hauled or towed load, while going down a long and/or steep hill? I know riding the brakes on hills can lead to problems when hauling and/or towing, so I try to safely avoid doing it as much as I can.

 

[emjohn4]

Tow/haul mode should do that for you automatically.

 

[Little Red]

Tow/haul mode should do that for you automatically.

Good to know. I must be jumping the gun, because that's never happened when in tow/haul mode. Next time I'm towing something, I'll give the computer more time to think, before I start manually down shifting.

 

[Ratket]

give it 3-6 mph.. it will kick inn

 

[Alex]

I downshift to 4th or 3rd regularly on long grades, don't really see a problem with it. I do the exact same thing in my big rig work truck lol

 

[audio1der]

I manually lock the trans into 4th once we get to speed every towing trip anyway, If a hill warrants it, I'll slow and let'er scream in 3rd. I never try and hold a speed, I just go as quickly as feels comfortable for the grade. Everyone behind me can deal with it.

 

[smiley]

The engine braking is very good. You can do it or it will do it automatically neither will hurt it.

 

[WulfGang]

The key to successfully negotiating hills is setting yourself up at the top of it.

My last tow I set myself up for one by slowing down enough to get into 2nd gear.
(2006 5.7L HEMI w/4spd. Dash says "1" "2" "D")

A good technique is to be in the "right" gear at the top and to ride 5mph below the speed limit or "safe" limit.
When you gain that 5mph back you brake to below 5mph again and then let off.

This is how I was taught in Trucking School and later used on many hills with #80k lbs.

Pay attention to grade % signs and other warnings for truckers.

On one hill there was a mandatory Big Truck stop at the top of a hill. I actually pulled off in that area, stopped, and let everyone go around me. Then I used the technique I just described all the way down.

Even still... it was rough. I noticed a little brake fade at the bottom because someone thought it was a good idea to put an intersection right at the very bottom of the hill with no time to let the speed fade off. It was all brake.

 

[Little Red]

give it 3-6 mph.. it will kick inn

There lies the problem, I start dropping gears once I reach the top of the hill.

I downshift to 4th or 3rd regularly on long grades, don't really see a problem with it. I do the exact same thing in my big rig work truck lol

My concern is damaging the transmission.

I manually lock the trans into 4th once we get to speed every towing trip anyway, If a hill warrants it, I'll slow and let'er scream in 3rd. I never try and hold a speed, I just go as quickly as feels comfortable for the grade. Everyone behind me can deal with it.

I don't go faster than my gut feeling, and downshifting has always helped me maintain that speed without the brakes fading.

The engine braking is very good. You can do it or it will do it automatically neither will hurt it.

Good to know.

The key to successfully negotiating hills is setting yourself up at the top of it.

My last tow I set myself up for one by slowing down enough to get into 2nd gear.
(2006 5.7L HEMI w/4spd. Dash says "1" "2" "D")

A good technique is to be in the "right" gear at the top and to ride 5mph below the speed limit or "safe" limit.
When you gain that 5mph back you brake to below 5mph again and then let off.

This is how I was taught in Trucking School and later used on many hills with #80k lbs.

Pay attention to grade % signs and other warnings for truckers.

On one hill there was a mandatory Big Truck stop at the top of a hill. I actually pulled off in that area, stopped, and let everyone go around me. Then I used the technique I just described all the way down.

Even still... it was rough. I noticed a little brake fade at the bottom because someone thought it was a good idea to put an intersection right at the very bottom of the hill with no time to let the speed fade off. It was all brake.

Thanks for the good advice. I always look for the "suggested speed" signs (never noticed their usefulness until I bought a truck), and then go from there on picking what speed feels the most comfortable.

I'm hoping to start CDL training come November to get my Class A, so looks like I'm ahead of the game. Lol

 

[Alex]

I cant see it hurting the tranny, all it is is a downshift. I could be wrong though, I'm far from an engineer. I'm more worried about the WOT downshift to 2nd prime weakness than a lil engine braking

 

[sandawilliams]

Is it bad to downshift to either 3rd or 2nd gear (pending speed, road condition, etc.) to use the engine compression to safely maintain speed and control my hauled or towed load, while going down a long and/or steep hill? I know riding the brakes on hills can lead to problems when hauling and/or towing, so I try to safely avoid doing it as much as I can.

Down shifting, within the RPM range, wont hurt anything. If in tow/haul mode it will down shift when it senses light pressure on the brake pedal. If you want to down shift manually it is best to do so prior to entering the down hill area and using the throttle to maintain your speed. A good driver pulling a load will stay below the speed limit in downhill situations. NEVER allow your brakes to heat up as an emergency stop wont happen if you ever need it.
(Longtime Colorado driver and truck driver)

 

[Little Red]

I cant see it hurting the tranny, all it is is a downshift. I could be wrong though, I'm far from an engineer. I'm more worried about the WOT downshift to 2nd prime weakness than a lil engine braking

I could see that doing some damage.

Down shifting, within the RPM range, wont hurt anything. If in tow/haul mode it will down shift when it senses light pressure on the brake pedal. If you want to down shift manually it is best to do so prior to entering the down hill area and using the throttle to maintain your speed. A good driver pulling a load will stay below the speed limit in downhill situations. NEVER allow your brakes to heat up as an emergency stop wont happen if you ever need it.
(Longtime Colorado driver and truck driver)

I don't like touching the brakes unless I have to. I've wasted more gas getting back up to speed from unnecessary braking, than I have from burnouts and doughnuts.

 

[Alex]

I know the WOT shift does damage, thats why I mentioned it. I dont actually do it, if i need to get up and go I downshift and then go for it. I was only using it as an example

 

[Little Red]

I know the WOT shift does damage, thats why I mentioned it. I dont actually do it, if i need to get up and go I downshift and then go for it. I was only using it as an example

I've always applied 1/2 throttle, which normally causes the trans to downshift, then, as a chevy guy once told me "unleash the horses".

 

[Alex]

Thats all I usually do for passing as well, but when i really wanna get going from hwy speed I'll drop it to 3rd(2nd prime) then hammer it, that way I know for sure that it won't try to downshift

 

[Little Red]

Thats all I usually do for passing as well, but when i really wanna get going from hwy speed I'll drop it to 3rd(2nd prime) then hammer it, that way I know for sure that it won't try to downshift

I'm going to have to remember this. Could save me from a big repair bill.

 

[Alex]

Seems like that WOT 2nd prime downshift is one of the biggest weak points on these trannies, I figure if I gear down then nail it, it should be a lot less stressful on it. Makes sense to me anyway