We are looking at 2005 5.4L Supercabs, but can not find a 2WD in this area that has a 3.73 axle with options we want, but they do have a 3.55 axle. How much difference does a 3.55 vs a 3.73 axle make when towing a 5,000# (loaded) trailer up steep mountain roads? Towing chart says 3.55 tows 8,600# and 3.37 will tow 9,500#.

 

Go with the 3.73 ,3.73 will give you more power.
I have a 04 fx4 screw with the 3.73 and i pulled a 4k pound trailer all the way and it had plenty of power. Cant really compare towing between them but i know a guy with the 3.55's and for speed the 3.73 is quite a bit better.

 

Thanks--We will probably wait and find a 3.73 just like we want, even it means missing out on the Ford Family Plan price this month.

 

You can get the gears changed by a well qualified shop for less than a Grand. What kind of difference are you looking at in your purchase price? I'd be inclined to get the otherwise perfect truck with the 3.55's and try it out. If it wasn't good enough, I'd have the gears swapped.
A few months ago I was getting quotes of about $1200- $1400 for swapping gears and adding limited slip on my '02 Lariat. The limited slip was about $500.

 

I've been pulling around 7000# loaded with 3.55's in FL. Not too any hills here but it does it ok. On a long mountain grade I could see a top speed of 40-45mph with it though. A 5000# trailer would probably do ok except on the really steep parts. And, like was said, you can always have the gears changed later.

Personally I'm saving for the superduty

 

Get the otherwise perfect truck with the 3.55's. If you find you need to install a higher gear ratio, skip over the 3.73 and get a 4.10 for the same price.

The 3.73 is only a few % different than a 3.55. The 4.10 will make a much bigger difference if you regularly tow a big load in the mountains.

 

Gear swap for 2wd is $500. Get the rest fo the truck you want now at the god prices.

 

There is no difference in the price, just can't find that particular vehicle w\ a 3.73 axle in this area. Have found many of them in California dealer's inventories, but we aren't moving to CA for a few months, and the Home Depot, & Ford Family discounts end this week (or so they say). We may go look at the truck that has everything we wanted, except w\ 3.55 axle. There's no way to test it's uphill capabilities here in SE Michigan where it is flat, flat, flat (compared to OR/CA mountain driving, which is what we will be doing). I saw on a post that one can't buy the 4.10 in CA.

I guess my actual question is has anyone had experience pulling approximately 5000# trailer in the mountains with a 3.55, 5.4L 2005 F150? vs a 3.73 axle? Would it really make that much difference? We are looking at a 2WD S/C.

 

What I meant was, if you find the truck that has everything you like except the gear, you can change it for $500. If you wait for 2006, you'll be paying much more than $500 to order with no family plan and 2005 rebates.

 

Well, I don't have a 05 F150, but my trailer is about #4500 all loaded up...... I tow in the 'mountains' all the time here in Western Washington (go over the Cascades all the time towing)

I've got 3.55's and 31" tall tires, so that reduces that gear ratio even more! I don't have any issues or problems towing in the hills..... Sure, I'm in second gear and pulling some 3500 rpms, but that keeps me at 55 mph nice and easy on the pedal and I the truck is not over stressed IMO....

I have aftermarket temp gauges for the Water and Trans and the most my water has gotten was 210* and the trans will stay at 195* during a long 6% + grade pull on a 90*+ day...... Oh, that's with the A/C cranked in the cab too!

On the flats, I keep it in third for the most part and it'll run at 2500 rpms going about 65mph or so. I usually just keep it at 60 and around 2300 rpms however. It will go into OD when it's flat and no headwind and as long as I don't have to press the pedal more to maintain speed, I'll let it run in OD.

If I had 3.73's or even 4.10's, I don't know that they would let me stay in thrid gear while going up the hills?? That's the only advantage I can see going to those gear ratios would do for me..... I mean, at 60 mph in third with 4.10's, I'd be pulling about 2600 rpms... Would that be enough to keep me in third on that long 6% grade?? If not, then I'd be in second and pulling a lot more rpms to maintain the same 55 mph I can now.....

I've got the older, less powerful 5.4, so I say get the truck you want, regardless of it's gears (well, 3.55 minimum...) and go from there.... A #5000 trailer with the new 5.4 will be a pretty easy tow with 3.55's IMO.....

Now, what I feel is comfortable and acceptable is probably totally different from someone else feels is comfortable and acceptable...... I mean, if you expect to be able to bomb up the grades at 70 mph then you WILL be disappointed..... If you want to be able to set the cruise at 70 mph and run in OD on the flats, then you will probably be disppointed...... The only way to do that with a #5000 + trailer is going diesel... Then, I still don't understand the need to go that fast anyway....... But, that's a different topic.... I like the nice and easy and get to my destination more relaxed then when I started! Crack that first beer and I'm set for the weekend!!



Good luck!

Mitch

 

The Ford salesman who posts regularly at fordtruckenthuasiast told me the difference in tow rating for a regular cab F-150, between the 3:55 and the 3:73 is 500 lbs.

 

Thanks a lot Mitch! Your answer is very informative and useful!

We do not go full tilt at any time, and especially towing a live horse or two, so sounds like the 3.55 might be OK for us.

We've driven over those Cascades (to Leavenworth) so know some of the roads you are acquainted with. They are similar to the Redding, CA to Eugene, OR Route over the Sierras/Siskiyous/Cascades which we plan to travel often.

The chart I have from Ford says that the SuperCab 2WD with 3.55 axle tows 8600#, which is 900# less than the 3.73 @ 9500# for 6 3/4' bed.

The 500# difference is correct for a Regular Cab, shortbed (126"WB)

The next main question then is, does this FORD chart really mean 8600# over steep mountain passes, or does it mean 8600# on the flat?

(My Ranger towed horse trailer fairly well on the flat, although rated at only about 2900#) The dealer who sold us the Ranger told us it would tow a horse trailer, and we believed him..... Caveat emptor.....That is why we want to do the research this time before we buy.

We appreciate all the input we can get.

 

Yeah, that's pretty much the trail I'm on when I'm heading East.

Well, it actually means you can tow that much IF your truck has zero options except for what's required to tow, a single #150 driver, no passengers, no stuff (no ice chest full of beer....). You see, in order to get to that weight of trailer, you also can't exceed any of your other weight limits like GVWR, front/rear GAWR and of course the GCWR. Ford and all the others basically come up with these "tow ratings" by taking the curb weight of the truck and subtract that from the trucks GCWR.

No consideration for tongue weight, hills, bad weather, wind resistance, etc.... Ever notice that in the television commercials, all you 'mostly' see for the 1/2 ton trucks is boats being towed behind them??? Hummmm....

In my case, when I'm all hitched up and ready to roll, my trucks maxed out on it's GVWR.... My truck has a "tow rating" of #7700..... I've got a trailer that weighs in at only #4500 and I've maxed out on just one of my ratings, so that's it, I'm done.....

Sure, I can tow more, and what I do tow, tows very nice and I'm more then satisfied with it's performance.... But, that would put me even more over my trucks GVWR and while I'm already a tad over, I don't want to be any more!

To sum up, all that "tow rating" does is let you compare towing capabilities between the different makes and models... To realistically think you can get that truck and then get a trailer that weighs that much and hitch it up and still remain under all your other weight limits is not likely to happen....

I'd much rather be maxed on GVWR then GCWR anyday.... That's where I'm at now, and my truck has 145,000 miles on it and still going strong. Tows really well too, because I'm not towing something that outweighs my truck! Can you imagine what towing a #8900 trailer with a #5100 truck would be like??? Which rig is going to control who??

Mitch

 

You have a point about not having the towing vehicle lighter than the loaded trailer, especially with horses moving around inside the trailer. We will keep the other weight ratings in mind. Thanks again!

 

Euro. I have an 02 Lariatt, supercab, 4x4 with a 5.4 with 3:55's. I tow a 27ft FlagStaff Superlite with a slide. 4200lbs dry weight and around 5200 loaded.
I tow in the North Carolina Moutains on ocassion, Black mtn area, Cherokee, etc. In the Mtn I stay in 3rd overdrive off and pull fine. No hard shifting and power to stay around 45mph with comfort. on the reg. NC highways with normal grades I pull 55mph and save on fuel and it pulls like a champ. Towing is not for speed. Id pull @ around 55-60 and tow at around 11mile per gallon 16 non-towing. Unless you are pulling in some straight up hills.. 3:55's should work. Mitch will tell you, dont try to be 1st up the mountain