Terrain also matters. As Wreckinball can tell you, there isn't much flat ground on 'the island' here in BC. If you live in a place like alberta, or florida (not sure but I think minnesota is one of the flatter areas), then you will see higher average returns for a similar equipped truck compared to one that roams in the hills or higher relative altitude.

 

Here in the Dallas area, the terrain is pretty flat. Driving across the country, though, will expose the truck to just about all terrain conditions.

I saw a video on youtube of a guy doing a gear swap in a 2004 F150 if I recall the model correctly. It seems rather involved and I don't own some of the tools needed. Unfortunately, most of my tools are in MA, hence why I am going up there.

YouTube - Rear Differential Gear Swap on Ford F-150

 

Thats a pretty good video up but its for a semi-floater axle instead of a full floater. Semi-floaters are cheaper and simpler to build, but more complicated to service. The F150s have the C clip to retain the axle in place at the differential end and the axle itself bears the full weight of the truck at the hub end.

Full floaters (D60, D70, and sterlings), are retained by a set of 8 bolts right on the hub and they bear no weight of the vehicle so you can actually remove the axle without even having to lift the truck off the ground let alone going through all the trouble of pulling off the wheels and brakes. Whats nice about the sterling, is the axle flange is sealed to the hub with an O ring instead of a gasket so its really easy to work on. You may still have to lift the rear wheels off the ground just to be able to roll the wheels far enough to line up the bolts at the flange with the splines in the spider gear for each side.

I also didn't replace any of the bearings when I did my swap and reused the shims that were already in place though ideally you would replace them too. The only regret I have is not replacing the crush sleeve with a solid spacer & shim kit. I don't remember having to press on or off any bearing on the pinion gear either but it was a long time ago that I did the swap.

 

I have a 94 4x4 with factory turbo I average 18mpg 3.55 auto

 

Does anyone know of a good how-to write up or video that would be more accurate for the F250 Full Floater?

 

C-clip axles ain't no semi-floaters mate, them be two different things

I was under the impression there ain't no solid spacers and shims available for the Sterlings, just for Dana axles and possibly the 14-bolt GM?

 

Solid spacer/shim was available aftermarket for the sterling last I checked.

As for semi-floater, that sure looked like a semi-floater C clip axle to me. So what is it then?

 

being an f-150 and not a LD (pre superduty) f250,id just guess its a full weight bearing axle/non float.

i did find it odd;
he used friction modifier in the open diff and,he didn't recalibrate the amount required,had it needed it with the added lube capacity.

 

If you pause at 8:49 you can see the axle and hub flange are one single piece. Pause again at about 9:23 and he is pulling the wheel flange and axle out as one assembly. If it were a full floater, there would still have been a flange on the outer end of the axle, but it would have been to bolt the axle to the hub, and the hub is what carries the actual lug stems for the wheel rim.

All the other info for setting up the gears however does carry over to a full floater axle.

This is what a full floater hub looks like:


Note there are two sets of 8 fasteners. The outer studs hold the wheel to the hub, while the inner bolts hold the axle flange to the hub. To remove an axle from a FULL FLOATER like this, you need to remove those 8 smaller bolts and rap the flange slightly with a mallet to pull it out. The vehicle will need to be blocked for this since your parking brake will be useless (I know, we all know this, but I figure I have to say it just in case.)

In a semi floating axle, the axle is ONLY subjected to torsional stress to propel the vehicle and the hub bears the full weight of the payload. In general, Full floater axles use an adjustible opposing tapered bearing setup (that gives two roller bearings per hub) while semi floaters employ a single roller for each side.

Here is a Semi Floater axle (this is a five lug, but they can be found with 8 lugs too):



You can just see the bearing behind the flange and also note the lack an inner set of bolts or protruding inner hub.

 

I've been doing a trip for work reasons this winter, and it's 110km's (about 65 miles) each way. Driving the dually, 2wd, regular cab, C6, 4.10 gears, takes about 25% more fuel than the crewcab, 4x4 with E40D and 3.55 gears takes.

Both have similar mileage on the drivetrains, both are original pump and injectors as far as I can tell. (So, bet both would really benefit from fresh pumps and injectors!!)

Same drive, same conditions, same fuel from the same station. I wish I could drive the cc still, I only drove it a few times with a borrowed dealer plate. (I haven't licensed it for the road yet, gotta sell the '01 first, too many vehicles right now!!)

 

For what it is worth I usually get about 14 MPG thats down the highway and around town mostly driving at or just under the speed limit (70 more than 60 cruse control when reasonable) I have a f350 crew cab with a service bed and an over head rack, 7.3IDI/na
E4OD and 4:10 rear end.(The one in my avatar) I haven't had on a scale yet but I wouldn't be surprised to find out that it weighs more empty than most of these others with a load on.
I live down the road near Austin so my driving conditions are going to be closer to what you can expect around Dallas (Weather Fuel road conditions and terrain.)
Mark

 

My Dad has gotten 22 mpg on his 1989 F250 2wd. He would do about 72mph. Light load of just a BMW motorcycle and a few days of gear. This engine is the one in my current truck and I get about 18 in the city and 20 in he high way with the E4od with empty loads

 

Hey guys, if you don't post your axle ratio it doesn't tell us a whole lot now, does it?

 

And how you drive also...

Jack rabbit off the line, or granny it...?

 

Im not sure what my axle ratio is but it is stock from Ford. If i was home id go read the door card. And the mpg I get now are pushed ahrd and fast miles being that im 18 and like to race every ricer i see. I dont win but ill cover him in smoke haha