Please Share Your Towing Expertise With An Amateur

From the outset, I'll let you know that mine is not actually a bullnose. But I think there is enough expertise here to find out more about what I'm going to ask.

I am thinking of using my truck (SuperCab, 5.0 EFI, E4OD, 8.8 with 3.08 gears, class III receiver hitch and trailer brake system already installed by P.O.) to tow a small camping trailer to CO in June. I'm not going to be attempting any of the mountain passes with the trailer connected. Just CO Springs area.

The questions for discussion: Has anyone here used a similar towing setup? I know the 3.08 will be about the slowest towing gear there is, but the tow chart for F-150's just has a " - " in the spot for my setup. Surely that doesn't mean that it won't tow, because it already has the Class III hitch with trailer brake. Somebody towed with it. But  " - " doesn't tell me very specific information.

What do you think?

First, you were missed.  And, SNS.  

As for towing with that rig, I think it'll do it.  Go to the Calculators page (Driveline/Calculators) and put 30" (my guess) in for tire size and 3.08 for the gears and you'll see that you'll be turning 2242 R's at 65 MPH in 3rd gear.  That'll be up in the powerband for the 5.0L and it should be fine there, but not at the 1592 R's in 4th.

In fact, I think you'd be ok on the passes.  If you put in 3000 for the desired RPM you'll see that you'll be running 56 MPH at those R's in 2nd gear, and it should do that handily.

Not having access to your owner's manual I can't say for sure, but I wouldn't be too surprised if Ford really doesn't recommend towing with that setup.  The tow ratings for trucks of this vintage are really pretty low.  For comparison, the owners manual for my '97 F-250HD gives a GCWR (gross combined weight rating = weight of loaded truck and trailer together) of 11,500 for a 5.8L, auto with 3.55 gears.  4.10 gears would bump that up to 13,000, so 3.08s would maybe drop it to something like around 9,000 lbs?  And that's a 5.8L, so a 5.0 would be lower yet.  Then subtract the empty truck weight (maybe 4500 lbs?) and you probably are looking at a trailer weight of around 2000 lbs or so (less if you're loaded up with camping gear).

That said, you need to decide how important the GCWR is to you.  If a PO put a class 3 hitch and trailer brakes on, he was probably towing over the weight rating.  And it's not like safety falls off a cliff if you go over the GCWR either.  I'm not saying overloading is always safe, but a lot of people push those limits.  You need to be comfortable with whatever you are doing, keeping in mind that other people's kids will be in the vehicles around you!

If it were me, and by "small camping trailer" you were talking about a pop-up tent trailer weighing around 2000 - 2500 lbs, I'd probably go ahead and do it.  You probably won't want to use overdrive much (the trans can handle it, but you'll need to spin the engine faster than that).  So use 3rd gear most of the time, and let it drop into 2nd on the hills.

On the other hand, if "small camping trailer" means a 4000 lb 24' hard-side trailer, I'd probably choose to look for a smaller trailer or a bigger truck.  That's just going to be too much tail for that dog.

Thanks! I'll be visiting the calculator and posting results here.

All right; back from the lab.

I looked into my diameter, and my 235/75-15's give me 28.877..." or rounded up, 28.9". But that number's real close to 29". Close enough, right? So I plugged that into the range calculator Gary has, which gives the following result:

RPM@55mph:
1. 5337
2. 3033
3. 1969
4. 1398

MPH@3000rpm:
1. 31
2. 55
3. 84
4. 118 (hahaha)

If I understand, this means if I am driving 55 in top gear, the projected calculated rpm should be around 1400RPM. Then, if the computer-controlled trans has to downshift to stay at 55, it will go up to almost 2kRPM. This doesn't seem too bad when I only think about it. I do understand that if I add another ton and a half of weight behind me, this will impede normal progress. However, I think that if I allow for slow going (you know, not trying to achieve that 118 mph with a trailer), it ought to be all right. The size of the trailer is TBD, but I always figured I probably couldn't pull one with slides or something. That's OK.

Any other thoughts?

You apparently had a lab assistant.  

But I think you've figured it out.  However, here's the way I'd say it:

You'll lock out overdrive w/the button on the end of the gear shift lever, and run in 3rd 95% of the time.  And at 55 MPH you'll be turning 2K RPM, and at 65 MPH you'll be turning 2320 R's.  I think you can easily do the 55 MPH and may well want to do 65.

When you get into the hills our mountains you'll pull it down manually into 2nd and can run 55 MPH at 3k RPM.

So, you don't have the trailer to test?  You could borrow my car-hauler trailer, which comes in around 2800 lbs and see what you think.  It won't have the wind resistance, quite, of a pop-up trailer, but it'll make up for that in the weight.  And, with two axles/sets of wheels on the ground it has more resistance.  Just take it for a spin and see what you think.

Or, maybe better, find a bit smaller trailer to try.  But, get one with brakes so you get the feel of that.

FoxFord33 wrote

...a small camping trailer...

That's essentially the same as " - "; NOT very specific information.

I've towed some pretty heavy crap with my 4.9L 4sp 3.08 Bronco; both locally and on rural highways in LA, TX, & TN.  And even though I tow at appropriate speeds, it's not a guarantee.  This was nowhere near the most weight or the fastest I've towed:





So don't start off towing near the max.  Tow an empty flatbed utility trailer around town; tow the UNloaded camper around town for a few days - just to find out how the truck responds, and to get in the practice of driving (wide turns) and backing it.  Then tow it loaded around town at low speeds before getting it on a major road at highway speeds.

The others have that part covered pretty good but .............
Does the truck have an add on trany cooler beside the one in the radiator?
If not you should add one, heat kills auto tranys. Add it after the radiator one.

Don't know what mirrors the truck has but if they are the dinky little car type mirrors and the left one is "closer than  they look" mirror get a set of trailer towing mirrors.
I have a set that fit on the doors. they hook in the top where the glass is, rubber bumpers brace on the middle of the door and has a bungie that hooks on the bottom of the doors.
They sit just outside the stock factory mirrors and with the 2 sets gives me a good view behind me.

The other would be a weight distributing hitch set up. This helps when the tong weight is too high or the trucks springs cant handle the weight of the trailer. When setup right it will raise the rear / tong up putting more weight on the front of the truck. It can also help to control sway but they make a device that can also be added to the hitch to control sway.

Also part of the sway make sure the tires on the truck are pumped up. I like to run max PSI when I tow, it keeps the side walls stiffer and helps stop sway.
That's all I can think of right now.
Dave ----

Very good thoughts so far, everybody. Thank you for discussing! I certainly hope others chime in, and I will look at their ideas as well.

Oops!
I thought I had the right gear ratio, but I didn't--I think!

Upon further looking, the vin decoder tells me I have the 3.08, but the axle tag on the door says "19" which means 8.8" 3.55! So I think that is right. Here are the new numbers, then:

MPH @ 5000 RPM in each gear:
1. 45 
2. 79 
3. 121 
4. 171 

RPM @ 65 MPH in each gear:
1. 7,270 (i)
2. 4,131
3. 2,683
4. 1,905

I marked first gear @ 65 MPH as an imaginary number, since (1.) I don't think the electronics will allow it to happen, and (2.) if it did, it might blow up the completely-stock motor. But, this does mean I will have more lower-end torque than previously thought, and I will be more able to pull uphill.

What do you think? New information for the better?

Those gears will give 15% more torque in all situations.  It is possible that you'll be able to tow in OD if the trailer is small enough since you'll be turning 1905 at 65 MPH.  And while the 2683 RPM @ 65 MPH seems a bit much, it isn't much more than Big Blue's 2500 at that speed, so would work nicely for towing.

If you go back to the trailer towing guide you'll see that with those gears you are "on the map" with a max trailer weight of 7100 lbs.  However, I think that is high, and especially so if you look at the 1986 owners manual.

Anyway, you can tow!