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Discussion Starter #1
2000 F350 Crew, LB 7.3 Automatic. 10K 5th wheel.

When climbing, shift down manually as needed to keep it in the 15-1800 RPM range? Or is there a better target RPM range?

Headed west to Yellowstone, haven't been since I was a kid. Have no clue what I am getting into. :)
 

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My 99 is a six speed, so a slightly different beast, but I would let the automatic do what it does best and that is help you maintain speed by shifting when throttle position and speed and computer say to. Don’t over complicate your vehicle operation. Now on the downhill runs, if dropping OD won’t hold back enough, don’t hesitate to drop down to second or first if necessary. I’ve even dropped into low range when I have steep grades and low speeds. One near me is 13% for five miles. Brakes get hot quick for the uneducated. The old logging trucks had water injection systems to cool brakes here years ago. Enjoy the drive out West. The main roads and highways are not that steep in most of Yellowstone, especially where you’ll want to pull that 5th wheel.
 

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As long as the transmission isn't hunting for a gear just let it work, if it is hunting take it out of Od

Keeping the engine around 2000 RPM's is about right

Sent from my SM-J737V using Tapatalk
 

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IMO, 2500 rpm is good pulling up long hills. 2000 is okay cruising the flats, less than that if not pulling a trailer. Just watch your egts if you have a tune.
 

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Went to Estes 2 years ago with the same rig. Trans got hot soon as I left Lyons, Co. Turns out the Superchips tow mode increased torque as it should but the operator had not increased cooling. Turned the chip off and made it home in one piece. Got a new 4 core with intercooler and left the chip off. I've been told I should switch to a 26 row cooler and understand why, just not sure how much longer I will keep this beast. My brother has a 2017, same config except the engine and he is planning to sell it in a year or so. I've driven his truck and like mine better but driving a 20 year old truck does come at a price. Hubs, ball joints, water pump, sway bar bushings (which I have fought to no end). My truck has 265K on it but I've only had it for 65 of that.
 

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I think you will be quite surprised at how well it pulls out west here. I have a 99 dually 4x4 PSD and pull a 31 5th wheel and have never had a grade yet on the highway that I could not pull 55 or more here in Montana. Hope you enjoy the trip.
 

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Discussion Starter #7
This truck has a 373 gear, which I don't care for, but at 70 MPH it's only turning like 21-2200 in OD. It is a 4x4 with factory wheel and tire size.
 

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Pulling a 9,000# travel trailer, I would disengage the OD when starting up a long hard grade and maintain @ 2,300 rpm in whatever gear required, manual down shifting if needed, until topping the grade. Then reactivate the OD and press on.
 

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I'm sensing a fear of rpms here...redline is what, around 3300? My tow tunes like to shift closer to 3000 and the powertrain can handle it. Drive by EGT and Trans temps below the limits and you are good to go. It's a fine towing machine...lol
 

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I'm sensing a fear of rpms here...redline is what, around 3300? My tow tunes like to shift closer to 3000 and the powertrain can handle it. Drive by EGT and Trans temps below the limits and you are good to go. It's a fine towing machine...lol

What he said. Let the transmission do its job. Higher RPM = Lower torque for the same HP. Let it wind out - the governor will keep it from blowing itself up. The real worry in the mountains is not climbing the grades. Its getting down them safely. I've said it many times but its worth repeating - you can go down a grade too slow a million times but you can only go down it too fast once.
 

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I agree in letting the trans do its job. IMO only to take it out of OD is if the trans keeps looking for a gear. Mine has 3.73 in it too and I don't worry about the RPMs when it down shifts. It don't get that high. Actually I tend to back out of the throttle a little and maintain about 55 up the grade. It will do more I just don't over push it.
 

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Discussion Starter #12
Made it back from the mountains in one piece. Thanks for all the help. Ran hotter than I expected going across KS but didn't get over 205 on the trani.

When it had to come out of OD and I still needed speed I kept it at 2500 to 2700 and no parts came through the firewall or the side of the block.

2600 miles and didn't use a drop of oil, which is amazing to me. My 460's would always use a quart on long trips.
Was scared to check fuel mileage and it didn't really matter because I was going either way. The 1st couple of tanks appeared to be at about 10 MPG. After that I quit calculating in my brain and just enjoyed the trip.

Ate some Duramax's and Cummins along the way. :)
 

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Yeah, it gets a little loud, but it just chugs along...
 

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F350cckc.

Thats a great report.
 

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With my six speed I liked to keep it around 2500 and above when pulling a big grade. Withe the auto I just hammer down and let the tranny due its job. Just watch the EGT's even a stock early 99 will hit 1400 when pulling a big hill with a load.
DENNY
 

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With my six speed I liked to keep it around 2500 and above when pulling a big grade. Withe the auto I just hammer down and let the tranny due its job. Just watch the EGT's even a stock early 99 will hit 1400 when pulling a big hill with a load.
DENNY
After replacing my up-pipes this spring I'm here to tell you that Denny is correct. Stock tune going up Eisenhower tunnel and Vail pass could exceed my personal max of 1300F at times. I even have a 4" turbo back exhaust and this happens. This blew me away as I assumed the stock Ford system (including exhaust) would never exceed 1200F. Never assume.

Mine is a 6 speed and it pulls best at 2500-3000 RPM up the hills, that is, if I can keep it there. Max torque is around 1800 RPM on these engines so it would seem 1800 would be best, but max HorsePower is around 2700 RPM so that is where I try to keep it. Torque is the amount of work performed, HP is the rate at which that work is performed. So keep the RPM's between 2500 and 3000 for best pulling up long grades.

I have a DP-Tuner installed and pull in the mountains on the stock tune so I don't have to watch EGT's so closely. In the flats I use one of DP's tow tunes and all is well as I don't have to watch EGT's except on long grades.

A stock, late model, 7.3 pulls the Rockies great.

7.3 PowerStrokes Rock!
 

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Yup, at elevation any tune that adds fuel will increase the egt to higher levels than stock. Add a big hill and watch that gage closely.
 
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