did you have to use a brake pedal rod for an F Super Duty? I've heard conflicting accounts when you switch to hydro boost that you either have to use the brake pedal rod, the whole pedal assembly, or nothing at all to make hydroboost line up properly.

 

that's all there too.

 

sorry man, I'm holding a sick 1 month old, so I'm reading the abridged version

 

OK, so weighed truck tonight.

Great news!!!

CAT scale with both tanks full of fuel, me siting in front (280#) and buddy sitting in back seat (260#). Also, I have a camper shell (see my avatar).

Front axle: 3540#
Rear axle: 3040#
Total weight: 6580#

Now if I remove passengers (540), shell (est. 150) , and fuel (190), truck weighs 5700#

But for towing purposes, let's use the .................................................. ...6580
My buddy weighs more than my two kids combined... 2 kids (210); dog (20)....-30
camper shell............................................. ...........................................-150
wife.............................................. .................................................. .....120
hitch............................................. .................................................. .....150
ice chest, gear in truck............................................. ................................75
Total............................................. .................................................. ...6745

Truck GVWR.............................................. ..........................................9200
Truck, fuel, passengers, grear in truck, hitch...........................................-6745
Available payload........................................... ......................................2455
With these numbers I am still under my axle ratings (FT: 4000; Rear: 6048)

So, I can tow a 5er with hitch weight up to 1600 comfortably and with a loaded weight of up to 8255 (6745+8255= 15000)

or

up to 11,755 loaded if I change rear axle to 4.10 which would also increase hitch weight to around 2000 which is still under the 2455 I have available

This is great news for me as I was feeling depressed that my F350 could tow a 27' 5er!
Now, what is depressing,........................the 5er I was looking at sold today

So, the search for a clean 5er continues, with a renewed enthusiasm that my truck can get the job done!

So, do my numbers add up or did I miss something?

 

Numbers sound right to me. I would definitely go to a 4.10 rear end.

 

Hey GJ....PM'd you yesterday

 

Sounds right. Mine with 4.10 gears maxes out at 12,500 lbs towing capacity. Going to 4.10 gears will have a negative effect on MPG though. With a 460, it probably won't be much lower than it already is though.

 

Other than the potential legal issues if the manufacturer's GCWR means anything to the highway patrol, I wouldn't suggest being in such a hurry to stick 4.10s in it. That ain't a cheap swap, so you might as well know you need it before you spend the money.


I know that I'm in the minority here who think that lower gears aren't always necessary, but I'll give you my opinion, knowing there are other valid opinions out there. An E4OD in overdrive with 4.10 gears has a total final drive ratio of 2.92:1. So anything you can pull with 4.10s in overdrive you can easily pull with 3.55s in drive. And even if you need to drop to drive with 4.10s, you're halfway there in drive with 3.55s already. So I'd suggest trying it to see what you think of the 3.55s first. You can always swap gears later.


I will admit that the trans will see more heat when starting out with 3.55s than with 4.10s, so if you do a lot of stop / start the 4.10s will have another advantage. And if essentially all of your driving is towing then it makes more sense to optimize the truck for towing (and 4.10 gears will be better for towing that load, no question). But for me, with the small amount of towing I do vs. the much larger number of miles I put on with a much smaller load, I'd rather be optimized for running almost empty and put up with a little less performance, and needing to downshift more often when I am hauling.

 

Realistically you are probably right. I get an average of 11 miles per gallon with my lower gear rear. I'm curious what a 3.55 would do for my mileage. I don't haul or tow anything enough to warrant necessarily needed them. I just know that starting off in first gear, I could pull a house with my 4.10 rear end. although I would like to have a gear vendor in my Dr line so that I can have the high gear on the highway, and shut it off for towing.

 

I would not worry about the 4.10s. Just lock out OD when towing and you will be just fine

 

Thank you to all for your input.


BTW....I get 14 mpg on the highway with my 3.55 loaded with full fuel, not towing anything. I like the 14mpg for such a large heavy duty truck.


As Bob and Brad stated, I am going to leave the 3.55s in place and see how she does once I get a 5er and start towing.


NOTE: Amazing to me that my truck (crew cab, long bed) empty (no fuel or passengers) is 5700 lbs.

 

I remember I brought up a thread almost exactly like this I think a year ago. Asking everybody what their truck weigh and how much they thought a two wheel drive crew cab would weigh on the scales. My truck with almost empty tanks I think was in the 5800 pound range.

pretty damn crazy when you think about it, especially for a truck the size. But definitely nice so you can have a few extra pounds towing.

 

Lol. And it was made out of steel and not plastic like newer stuff.

 

actually,since he has a 2WD,SRW it's very affordable.simply swap in a whole used rear axle w/4.10's.couple hundred bucks and done.no need to pay for r&p and the specialty labor.
though i agree,i don't think id be in a hurry to swap to 4.10's either.however with a 27' 5ver id pretty much be prepared for them,and start sourcing my rear.