Which gear when pulling over mtn passes?

You will find that in 2nd gear the rpm's will rise to over 3500rpm or higher. The engine is designed to run that high, it won't hurt the engine. Watch you temp guage.

When I drove over a pass (Wolf Creek Pass), I gave the engine about half throttle and let the engine find its way while going up. Just an easy cruise to the top. No strain on anything.
Going down, I started in 2nd and it held fine for awhile. As 2nd started to slow down the rig, I shifted to 3rd. When 3rd started to slow down, I went to drive and had no problems maintaining the speed limit. Never had to use the brakes.
Keep in mind it is easier to start down hill in a lower gear and if too low, just shift up one gear. If the gear is not low enough, you will have to do more braking to slow down to use a lower gear.
Pat

Shift, as necessary, to keep the engine in the best torque band for your engine (probably about 4k rpms for most gassers). If you are using a lot of the gas pedal and the truck is starting to slow, then you need to downshift again. Repeat as necessary all the way to first.

More importantly, if you need 2nd gear to go up the mountain, you probably should be in the same gear going down so as not to overheat the brakes. General rule of thumb is to use the same gear going down that you used going up. Good luck.

I know how I would do it. I do my shifting to the gear that makes the engine happy and easy to know by listening. This should keep the trannie from hunting up and back down. Get the speed you like and enjoy the drive.

chevman

CND SuperCrew wrote:
Typically use D w/TH and the tranny will down-shift on its own as need. Not familiar with the dodge but I'm going to guess you have a 4spd tranny maybe. You may want to manually down-shift into a lower gear to go down the mountain. Then allow the engine to slow you down while using your brakes as needed to keep your unit from "running away"...

The 04 Hemi should be a 5 spd auto. The diesels used a 4 spd.

Bottom line. Make sure it is in the gear you want it to be. If D and tow/haul doing it for you, that's great. If not, do it yourself.

the bear II wrote:
The key is to not let the engine "lug" when going uphill. I usually use the gear selector to go down through the gears manually as I lose speed and RPMs.

You may lose some power due to elevation so lower gears will help fight this loss of power.

I have climbed and gone down some hills in first gear at 22MPH... you get to see a lot of scenery at that speed.

May lose power?

It's 3% for every 1Kft. So ~ 30% loss of power over the Colorado passes.

30% is a huge amount of power to lose, right when you need it most.

You'll be needing 2nd to get up some of the mountain passes. Whether you do it or let your truck do it depends on you and the truck, I suppose! If the truck will hold the gear and avoid jumping from gear to gear quickly (say, every 30-60 seconds), you're probably ok leaving it in D. If it is shifting from 2 to 3 back to 2 over and over again, that is called 'gear hunting' and should be avoided by shifting into 2 and leaving it there until the grade lessens and you can hold 3rd.

Like a previous poster mentioned, you need to downshift to keep speed under control coming down the hills as well. That is a more critical aspect to pulling in the mountains IMO. Getting your transmission hot is one thing; cooking your brakes is quite another!

Good luck!

Since I only have a 4-speed, I often end up manually shifting into 2nd. It downshifts fine, but 2nd speeds me back up pretty quick and I have to back off the throttle to keep my speed down, which causes an upshift but 3rd doesn't make enough HP for me at full load on 7% grades. So locking it in 2nd lets me maintain a steady speed easier.

The key is to not let the engine "lug" when going uphill. I usually use the gear selector to go down through the gears manually as I lose speed and RPMs.

You may lose some power due to elevation so lower gears will help fight this loss of power.

I have climbed and gone down some hills in first gear at 22MPH... you get to see a lot of scenery at that speed.

Try to keep the tach in the optimal torque zone.