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Old 02-17-2016, 04:42 PM   #15
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Originally Posted by Hittenstiehl View Post
Okay thanks everyone.

If the transmission shifts itself then what is the 3 the 2 and the 1 for.

The original question is how to properly drive up or down steep grades and how to properly use the 3,2,1.
321 is for going down hills, when you don't want the transmission to shift to a higher gear and you want some more engine braking. When you go up a hill, the transmission will automatically downshift, so you don't need to use 321 unless it is hunting (shifting repeatedly). If the engine is running too fast and making too much noise back off the throttle.


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Old 02-17-2016, 04:43 PM   #16
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Originally Posted by avionstream View Post
The tranny should down shift itself to third then second. If the engine is revving too high, slow down to lower rpms. Anyone, is this correct?
Exactly right.

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Old 02-17-2016, 04:53 PM   #17
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OK Jeff that was a good explanation in a way I was able to understand. Thanks.

It hasn't been a major problem but occasionally when that engine whines I get a bit worried about transmission. And of course you always want to protect those brakes on the way down.

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Old 02-17-2016, 04:58 PM   #18
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The reason for 3,2,1 is to give you positive control of what gear the transmission is in. Just like a manual transmission. Everyone has given you great advice, but as stated above no two trucks, hills, loads or drivers are the same. You need to learn your vehicle and come up with a procedure you are comfortable with (IE pucker factor).
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Old 02-18-2016, 03:35 AM   #19
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Driving on Steep Mountain Grades

This is how we handle long steep grades (e.g., I-70 Eisenhower Tunnel west of Denver, CO):


Make sure tow/haul switch is ON. Let transmission select the appropriate gear. If transmission hunts, manually select the gear the transmission has chosen, to stop hunting. If engine rpm is excessive, slow down.


Pick a target speed appropriate for the grade, which is slower than the speed limit; for example, 45 mph in a 55-65 mph speed zone. Manually, downshift from DRIVE or highest gear until target speed can be maintained WITHOUT BRAKES being applied. To maintain this speed, it's preferable to use the accelerator pedal, rather than ride the brakes.

If 45 mph (or other target speed) cannot be maintained without brakes, downshift one-gear-at-a-time until this equilibrium can be achieved. On extreme grades, this may be 25 mph in first gear.

If first gear will not hold speed, as engine approaches higher rpms, brake moderately for a few seconds to slow speed by 5-10 mph. Then, release brakes and allow speed to slowly gather. Do NOT allow transmission to shift to a higher gear. Repeat intermittent braking, as necessary. If grade continues, after several brake applications (and before brakes overheat), stop in pullout and allow brakes to cool for 20-30 minutes before continuing.

If target speed CAN be maintained, and a faster speed (still slower than the speed limit) is desirable, slowly increase speed and shift up a gear, as necessary. If the new target speed safely can be maintained WITHOUT BRAKES, continue your descent.

Important Notes
  1. Never coast with transmission in NEUTRAL.

  2. Do NOT use brake controller manual actuator, except in an emergency (e.g., to stop trailer sway). Specifically, DO NOT RIDE TRAILER BRAKES. Trailer drum brakes fade faster than TV disc brakes; and in an emergency, you may need full braking power on your Airstream.

  3. Do not block (or park in the approach to) a runaway truck ramp. Besides getting stuck in deep gravel, you risk a collision by a runaway vehicle.
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Old 02-18-2016, 04:36 AM   #20
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Phoenix is correct and it's the way Class A CDL drivers are trained as well as School Bus Class B CDL drivers are trained. The vehicle should select the proper gear while going up a hill. Upon reaching the top of the hill pick the speed you want, as mentioned slightly lower than posted speed and manually select the gear the computer selected while going up the hill, and when you vehicle reaches 5 MPH over your selected speed, bring it back by using the brakes then brake until speed is reached you decided on and then off the brakes and let the engine and tranny do the work. Process works. good luck and enjoy


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Old 02-18-2016, 12:57 PM   #21
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Each engine has an RPM rating for peak HP and peak torque, if it isn't in your manual, look it up on line. When climbing a steep grade, try to keep the engine at or near peak torque, while maintaining a safe speed. If your instruments include a TEMP gauge, keep your eye on it, if it starts to get too hot, ease up on the gas and drop a down gear. The previous advice about "the gear you climb should be the gear you should use to descend" is a good rule of thumb. Your truck has instruments for a reason, learn how to use them. Using your gears will save on your truck and trailer brakes as well as your engine.
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Old 02-18-2016, 01:37 PM   #22
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These have been excellent suggestions and well explained. Thank you all!

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Old 02-18-2016, 01:49 PM   #23
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Remember as you start down a longer grade downshift and start slow. You can always go to a higher gear and speed up but slowing down if decending too fast can be a problem. Going up is not your big problem.
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Old 02-18-2016, 01:49 PM   #24
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Going uphill , start by letting the transmission select the gear. BUT, if you find it "searching" a lot--going back and forth between drive and 3rd or 3rd and second, manually select the lower gear. Constant shifting may overheat and/or wear your transmission excessively. Adjust your speed to where your rig feels comfortable within the torque range and note the RPM's on your tach for future reference. If you need 2nd to maintain uphill, try not to run near redline for any length of time, and definitely watch both the engine heat gauge and transmission heat gauge if you have one. Obviously, ambient air temperature is going to have a large effect here--its makes a difference if you'r climbing in 50 degree or 100 degree air temps flowing over your radiator(s).

Have a conversation with your engine servicing people--see if you can find one who tows with your vehicle and ask for their specific advice as to what rpm range you should use for more extended periods of time, and whether any engine or transmission heat gauge increases are OK or not OK for your engine and transmission over the long haul. Because automatic transmissions are actually quite delicate (in that they do not have a good tolerance of any foreign matter in their lubricating fluid), consider changing your transmission fluid annually if you tow 10K miles or more per year--a cheap preventative measure.

Over time, you will learn what grade of hills your rig is comfortable climbing at which gear and which rpm.

For downhill, do note the % of grade signs when they are posted. If the downgrade is marked 6 or 7%, for safety you might want to make sure you're in the right lane, slow to 45 mph, and shift into second (if that's within the acceptable RPM range for your vehicle--otherwise, slow more.) If you go to 40 or below, be sure to turn on your flashers. As you go down the hill and take your foot off the accelerator, if the truck slows down a lot using just the engine, you might consider shifting up to 3rd and see if the engine holds against the hill, again with no braking. And if it holds easily in 3rd, then shift up to Drive and see how that works. Soon you will learn at what slopes you need to be in which gear to utilize engine braking while getting the best controlled speed over the ground and not taxing the engine by being way high up in revs. Generally, engine temp is not an issue going downhill, but transmission load is always to be considered.

You should be using your brakes only occasionally, and lightly. Going downhill (or in hilly country in general) you may want to set your trailer brakes for a bit more aggressive braking--too strong for driving in bumper to bumper traffic where it would jerk you a little bit every time you touch the brakes, but not so strong that the trailer brakes ever lock up. By having the trailer brakes a bit stronger, you assure yourself that the trailer brakes are taking the full weight of the trailer and not pushing the tow vehicle down hill. My wife and I both prefer an aggressive enough setting that the trailer exerts an ever so slight drag on the tow vehicle (she actually feels safer while driving with a more aggressive setting than I feel is safe.) This lets it serve as a "sea-anchor" and helps keep the rig tracking straight. A light use of the brakes keeps them in reserve if you need an emergency stop. If you're braking all the times, they may be building to a glaze-over from heat and reduce efficiency.

Of course, going downhill it will take you much longer to stop, so you should allow that in following distance--no time to even think about tailgating--but I'm sure you know that!

If you crest the top of a hill in third and then shift to drive and as you start going down, the engine allows the rig with your foot off the accelerator to accelerate continuously, brake softly and firmly to bring the speed down to a level at which you can downshift to 3rd, and do the same thing if it's still happening in third so that you can safely downshift into 2nd. At this point, you will most likely be doing about 40 mph--if you're going much faster, you may be approaching redline on the tach. This is fine for short periods, but probably is not a great idea for long periods of time, so the slower speed at more moderate revs in the low gear is better for your rig. and again, hazard flashers if you're doing 40 or under.

Typically, if we don't know the slope as we crest the top of the hill, we will downshift one gear from drive (we have a 5 speed, so that means 4th on our "manumatic" transmission) or 3rd if it's obviously fairly steep looking, and then brake and downshift as described above if necessary.

Of course, a headwind will help you slow somewhat, and a tailwind will push you down harder, but all of the guides above should help you find the approach that is most comfortable for you to find good uphill and downhill "sweet spots" in your tachometer range to keep your engine and transmission running in a comfortable range while maintaining a safe and controllable speed uphill and downhill. Brake as necessary before entering downhill curves so that you go through them at a speed lower than the posted curve limit until you learn what your vehicle will comfortably handle. (We find that our rig is quite comfortable at the posted curve speed limit on steep slopes, but we always brake to just under so that we can negotiate the curve without brakes and come out at a speed not greater than the posted limit.)
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Old 02-18-2016, 02:15 PM   #25
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Your Ford probably has a tow/haul switch which may help with engine braking on downhill grades, depending on the model. Either way, it changes the shift pattern and protects the trans from overheating etc. to some degree.

As previously stated, you can "help" the truck make decisions on an uphill grade if it is changing up and down frequently and traffic keeps you from varying your speed to compensate, by shifting to "3" which will hold it in a lower gear. "2" is just a lower version of that and you would rarely use it unless you were stuck in traffic on a hill at speeds around 30 mph.

On many Fords, depending on year, "2" will also start you off in a higher gear which is usually only helpful if you are trying to get going in extremely slippery conditions. You can check this on your vehicle by starting forward on an uphill in "2" slowly and then switch into "1." If your vehicle is made that way, you'll feel a little jerk as it moves to low gear.

"1" is the lowest gear and most effective for engine braking, but only at low speeds. Your vehicle won't downshift into low unless you are travelling at about 25 mph or less. Where you might use it is if you are descending an extremely steep, longer incline, maybe with a trailer, and want to keep your speed very low to protect your brakes. If that were the case, you would switch into "1" at the crest of said incline and use your brakes as little as possible, but enough to keep your rpms at a reasonable level.

Good travelling and much happiness to you and yours!
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Old 02-18-2016, 02:48 PM   #26

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"avionstream The tranny should down shift itself to third then second. If the engine is revving too high, slow down to lower rpms. Anyone, is this correct?"

Any vehicle/transmission/TV equipped with a tow/haul and a PCM,(powertrain control module), will choose the proper gear.....if you feel its rong, look to the engine power/torque specs and drive to the sweet spot.

AF #1

"Sticks & stones can break your bones...and hail will dent your Airstream"

So when is this..."old enough to know better" supposed to kick in?
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Old 02-18-2016, 03:42 PM   #27
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I have the same truck with a 30' Classic. Going up hill just leave it in drive and watch you Trany heat cage. I get real nervice at 210 degrees. When it starts to get close to that I ease up a little. Down hill decide your maximum speed you want to go and start at that speed. I use a gear that puts the tach at 3000 RPM's. I am conservative.
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Old 02-18-2016, 06:17 PM   #28
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I'm have been driving for over 56 years now, rallying, long distance driving, a licenced Aircraft mechanic, (A.M.E.) towing several RVs and so forth.
I have now a Ford F-150 EcoBoost, with 'tow-haul', but I prefer to manually shift it with the neat little buttons on the side of the shifter. Why????
Because I prefer to DRIVE the vehicle in accordance with what the vehicle is telling me; and NOT what some little 'office-bunny' in a cubicle who has proven that he/she has no idea of what my current situation is on the road.
'NWGETTAWAYS' IS RIGHT; along with Jeff; the best RPM to run your engine under load is at the peak torque of the power curve, all other things being equal.
However, not all things are equal, and under load it's best to keep your RPM up to allow for better engine cooling; especially going uphill with an RV. Use a lower gear and let the engine do it's job.
Going downhill, same thing. Use engine drag to keep your speed down, and control it with occasional braking.
I usually prefer to run at 2500 RPM with any vehicle, as I feel that it is the most efficient speed; and I'm fortunate in this respect, as the 3.5 EcoBoost max torque is at 2500.
My F-150 has a 3.55 final drive, and I normally use 4th. speed on the secondary roads, and 5th. on the 400 series highways. (Akin to U.S. turnpikes)
I never use 6th. gear, as it's too long legged, and overworks the engine at far too low an RPM.
I cannot see the logic in many of these manufactures offering 8 and nine speed trannys, as the engine RPMs would be just too low; unless they are offering final drive ratios of 4.56 up to 5.30 or so.
The engine needs to 'swing' at it's most efficient speed, and the ancilliary services need speed too. water pumps especially, generators, power steering, air conditioning pumps and so forth,

To those who would rely on the auto transmission doing it's job all the time, I say this:
Get to know your tow vehicle, and LISTEN to what it's trying to tell you.
The vehicle is the FINAL AUTHORITY on what it wants for best performance; listen to it; pay attention to it!
The first thing you would do in a new vehicle is read the directions and follow them; THEN learn to do it the right way, and enjoy many years of good motoring on the RV road.

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