I've got a 99 F350 CC short bed 4x4 7.3 SRW auto trans. It has a 3" shackle lift, intake, exhaust, and 285 tires, otherwise stock.

Today I had to tow a 7500# trailer, verified by scale, for about 40 miles. I towed it with my trailer hitch using a 3" drop tongue (rated for 5k lbs, I know, I was over the weight limit).

The area I was towing in was pretty hilly. I have read when towing this kind of weight not to use the over drive at all. Is this true, or should it only be turned off while going up hills?

Anyway, with the overdrive off, I could only go about 45-50mph around 2300-2500 RPMS. Which is pretty high for the truck to maintain for a long period of time.

So those of you who pull heavy trailers, how do you do it? Do you use the O/D?

I did get it up to 60 once but the trailer was not loaded correctly (too much weight on the rear end), it was raining, and the trailer (14' + tongue) started swaying back and fourth real bad... pretty big pucker factor.

I had trailer brakes and didn't have much of a problem stopping. Going up a steep hill the truck seemed to struggle with the weight behind it. Yet I had guys passing me at 65-70mph with huge 5th wheel trailers behind them.

 

Not really. The truck can run at those rpm's for a couple of days straight (or until you run out of fuel) without causing any harm. Depending on how steep the hill is, I wouldn't recommend dropping below 2200 or 2300 rpm's or you're likely to lose speed going uphill.

7,500 lbs. isn't heavy, especially on a flatbed trailer. Making sure it's loaded correctly is VERY important as you've discovered.

 

Isn't the hitch itself only rated to pull 10,000 lbs? 7500 is 3/4ths of it's limit...

 

I pull an average of appx 10000 lbs regulary, a must is make sure the trailer is loaded properly..as far as over drive the only reason to turn it off is if the truck starts shifting in and out of overdrive its called searching..shifting back and fourth from drive to overdrive...

 

What gears do you have? Should'nt be a problem towing 7500. I use od towing all the time as long as the trans is not downshifting a lot. Did u try the od at all & see if the rpms dropped?

 

I use my manual transmission equipped Ford IDI or PSD.

 

Exactly what he said ^^^ if the trailer is loaded right 7500 shouldn't make that FORD strain at all

 

The majority of the weight was on the back end of the trailer. It took three men standing on the tongue just to get the trailer tongue to come down far enough to latch onto my ball....

 

I pull a 13.5' high 34 foot 5th and can pull any speed on the flats, and the slowest I was going was a bit below 50mph up Raton pass in NM. Haven't pulled the Rockies yet, but I'd imagine something around 35-40mph and I'll be happy. I am stock programming wise. Sounds like you are running a bit slow. The 25' travel trailer I pulled would move along up hills at 65-70mph no problem.

To answer your question directly, I pull in O/D whenever I can, but I am running a 6spd.

 

You got to be *****ing. 600lbs to latch onto the ball, somebody would have been moving stuff before I would have moved that trailer. You sure lucky you didn't have to make any quick stops, talk about a jackknife

 

I tow a 3000# trailer loaded with up to 5000# on a big day. Not the heaviest of trailers, but not the lightest either. Ive got 2" shackles and load bags in the back. Never has any trouble. Cant even tell the trailer is back there on the skinny pedal. The brakes will let you know there is a load behind you once in a while though.

 

i tow around 10000+ and pull i od all the time. just load it right will make it better.

 

X2, its a wonder you made 45mph...trust us these trucks will pull more than they can stop.......

 

The majority of the weight should have been over the axles of the trailer.
Your very lucky you didnt wreck.......... NEVER NEVER load a trailer with no tongue weight. or -600 lbs for that matter.

load the trailer with at least 10% to 15% of the trailer weight on the hitch.

 

I can tell you that those of us who pull heavy trailers don't do it that way. When you put that much weight behind the axles of a trailer, it will start to sway and fishtail at higher speeds. It's a good thing you took it out of OD and kept the speed and rpm's low. If you went down a steep hill at 70 mph with that load there's a chance you would be in the hospital right now.

As mentioned, if you're in that situation again, re-load the trailer so it's not rear end heavy.