OK, I Need to know what kind of gears to put in the rear. I have 4.10 and would like tho go with 3.55 or even lower to 3.23. I do not pull very much at all and would like to get more fuel milage out of it. I have looked online on ebay and jegs and cant find my rear end. I just get like 8.8 or 9" ford. What other name does this rear end go by. Im almost positive I have a sterling 12.25 (or is it 12.5) on a 93 F350 dually w/e40d.

What gears do yall recomend for highway driving for a 8,000lb truck. I don't think I will load it down too much with the turbo I just put on. I barly have to give it any throttle up hill with wind on a bad day. I would just like to lower my RPMs. I get 16mpg at 65 and have heard some people at +20mpg. I understand the issue with heavy loads its just I like to drive it so its basicly running with stuff in the bed and cab. I see several people with 3.08 on here but most have a c6 setup. How well does those gears work for those of you with the E4OD. Ocasionaly I pull a 6,000lb trailer but not often and not through the mountins (yet). I hear after about 20 mph you can't tell the differnce. I Wants as much input as yall got. Thanks

 

You should have a Sterling 10.25 or 10.50.
I changed my 93 F250SC E4OD from 4.10 to 3.55. Mileage went from 18 to 22 on hwy empty. Have ATS 088 turbo. Cruise at 70mph is 1925RPM. You could go with 3.73 gears and pick up mileage but have more umph than 3.55 gears. I pull an 8,000lb boat and it does what I need. You have a bit more truck though.

 

As long as you don't have 4.11 gears, than you can go all the way down to 3.08s if you wanted.

The E4OD actually handles 3.08s better than the C6 because it has a wider ration 1st and second gear. I've had both in my truck.

HOWEVER, unless you are going to increace your cruising speed to 70 MPH or higher, you might not benafit as much from 3.08s as you would from 3.54s. Although with 3.08s you could cruise in 3rd gear if desired and still get similar performance to your 4.10 setup right now if towing is a concern.

 

Around town I do almost 20mpg on my 93' turbo, 5speed Standard with a 3:55 while I only get 16mpg on my 91F350 E4OD with 4:10's so the gearing really does make a significant difference to your milage.

Man that is a moster long truck you got, I did not even know they made Super-Crew Cab like that.

I thought about changing the gears in my 91' but it is a 4x4 so the hassle and cost are just to great, however with the cost argument is getting better by the day with diesel here now at almost $5.70 a gallon.

Seb.....

 

is there a different speedo gear to get it back to read right when changing your gears?

how do i identify my ratio? i know the spin the pinion and count method but i figure the difference between 4.10 and 4.11 is so small that wouldnt work, i also figure they have markings on the trucks door jamb that should tell you a code like my toyota does

 

Whats the holdup with having 4.11 and what rearend would that be in.. I think I have the 10.25 ( must have dreamed up 12.25) I have no problem rasing my cruise speed to 70 I just stay at 65 due to it gets a little better on fuel. When i go to tulsa from here I sometimes run 80 on the toll road so that would be no problem there.

Im leaning towards 3.55s (or a gear between 3.55 and 3.08 like 3.23)
Great examples guys, Are there anymore out there for comparison?

Hamburger, No, its not stock, Some company stretched it along with a few others. Thanks

 

3.73s might even be a good choice,but as long as that sucker is a brownie box would be a good option too.

 

Speedo correction depends on the year. 1992 started using a VSS magnetic pickup sensor on the differential. This is not affected by a change in differential gears. 1991 and older uses a conventional cable driven speedometer, and you will need to swap the plastic gear(s) in the output shaft housing to get the correct reading. Its quite easy to do, but if you have to replace the drive gear as well as the driven gear, you will have to drop the output shaft housing. But thats still not as big a deal as replacing the differential gears.

Counting the teeth of the gears is still the most accurate way of figuring ouy what you have. 4.10 gears will have 41 teeth on the crown and 10 on the pinion (41 / 10 = 4.10). 3.08s have 40 on the crown and 13 on the pinion (40/ 13 = 3.0769....).

 

Brownie box..? Is that a gear vender box?

 

Basically.

I can translate trucker talk.

 

I don't know much about Brownies but there was a discussion of them a while back on a thread-probably about a month ago.

The Gear Vendors attatches on your tailshaft/tail housing and they cost almost 3 grand last time I checked. (If you didn't already know that.)
I think brownies are actually "shifted" the GV is "button" operated. Basically Brownies are "old school".
I'd like to have a divorced type GV and install it after a Cummins-driven Allison 545 auto then into a divorced Ford 205 with a Ford Dana 60 in the front. With that set-up you could use the GV in 2 and 4 wd. I would put it in a Crew Cab but your megacab would be perfect for that. It would be a LOONNGG drivetrain. With fuel prices where they are I doubt your interested in making your truck a 4x4.

 

I thought about 4x4 but Im too busy anyway to convert it. I asked a few folks that were truckers and they didn't know what brownie boxes were. I would definatly want the manual ****ed one though.(unless the gv is like air operated with a air valve switch like a splitter on a twin screw) I don't want the electric push button cause in almost everything I have seen it has failed in at one time or another. I may start looking for a gv or similer setup though. If I get a "divorced" unit, that would eliminate my carrier bearing at least. Wonder if used units are easy to come by. Thanks for the input

 

I bought a set of used 3.55's for my truck (front and rear) for a song- but getting them installed will cost a pretty penny.

I still want to get it done, just not sure when.

Also- if he has a dually isn't his rear axle a Dana 70? Or am I wrong?

 

There's a good thread here on brownies, https://www.ford-trucks.com/forums/5...ie-thread.html

Without beefing up an E4OD, I'd be a little concerned running in dbl overdrive. The low rpm might/would be to low and cause problems. It might even be a problem with the ZF5 with the 5th gear trouble that trans has. I don't "know" that there would be problems with a dbl overdrive. Seems the 2 trannies have enough trouble in stock form.

 

If you ever want to convert to 4wd, than don't swap to 3.08s. There is no front axle that would fit the front that can fit the 3.08s. 3.54 and up only.