I have an axle I bought and am reselling off a f250. I was told it was 4.10 gears. The seller is from pretty far away and wants me to be sure. I have the axle tag but can't figure it out. It says:

C 426 B
10 10 5 2023

Is this an axle code 42 (4.10?)

 

Are you missing a number from the front of the "10 10 5 2023" line, and is "2023" actually something like 2D23? 4 10 10 5 2D23 would make sense, open 4.10s, Ford 10.5", built in April 02 for a 2002 or 2003 MY truck.


Edit: thought you had the truck, not just the axle.

 

What year is the F250 you got the axle from? AXLE codes can vary from year to year.

The only thing I can tell you is, this axle does not have Limited Slip.

1959 thru today: If the AXLE code begins with a letter: Limited Slip. If with a number: No Limited Slip.

 

No clue what it came off. I might need to pull the thing out of the weeds to look at the tag better, I like the first suggestion about me missing a number.

 

Here are the axle codes :

Axle Type
31 — 3.73 non-limited slip, F-250/Excursion
C1 — 3.73 limited slip, F-250/Excursion
32 — 4.10 non-limited slip, F-250
C2 — 4.10 limited slip, F-250/Excursion
33 — 4.30 non-limited slip, F-250
C3 — 4.30 limited slip, F-250/Excursion
36 — 4.56 non-limited slip, F-250
C6 — 4.56 limited slip, F-250
41 — 3.73 non-limited slip, F-350 (single rear wheels)
D1 — 3.73 limited slip, F-350 (single rear wheels)
42 — 4.10 non-limited slip, F-350 (single rear wheels)
D2 — 4.10 limited slip, F-350 (single rear wheels)
43 — 4.30 non-limited slip, F-350 (single rear wheels)
D3 — 4.30 limited slip, F-350 (single rear wheels)
46 — 4.56 non-limited slip, F-350 (single rear wheels)
D6 — 4.56 limited slip, F-350 (single rear wheels)
61 — 3.73 non-limited slip, F-350 (dual rear wheels)
F1 — 3.73 limited slip, F-350 (dual rear wheels)
62 — 4.10 non-limited slip, F-350 (dual rear wheels)
F2 — 4.10 limited slip, F-350 (dual rear wheels)
63 — 4.30 non-limited slip, F-350 (dual rear wheels)
66 — 4.56 non-limited slip, F-350 (dual rear wheels)
F6 — 4.56 limited slip, F-350 (dual rear wheels)
81 — 3.73 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E1 — 3.73 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
82 — 4.10 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E2 — 4.10 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
83 — 4.30 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E3 — 4.30 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
86 — 4.56 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E6 — 4.56 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
88 — 4.88 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
EW — 4.88 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
G3 — 4.30 limited slip, F-450 Chassis Cab
73 — 4.30 non-limited slip, F-450 Chassis Cab
78 — 4.88 non-limited slip, F-450 Chassis Cab
G8 — 4.88 limited slip, F-450 Chassis Cab
75 — 5.38 non-limited slip, F-450 Chassis Cab
G5 — 5.38 limited slip, F-450 Chassis Cab
GW — 4.10 limited slip, F-450 Chassis Cab
98 — 4.88 non-limited slip, F-550 Chassis Cab
K8 — 4.88 limited slip, F-550 Chassis Cab
95 — 5.38 non-limited slip, F-550 Chassis Cab
K5 — 5.38 limited slip, F-550 Chassis Cab
KW — 4.10 limited slip, F-550 Chassis Cab

 

Pull the rear cover and count the teeth on ring and pinion...then divide.

Or, turn the pinion and count the number of turns to complete one revolution of the rotors/tires/whatever is bolted on.


Since the second line on the tag starts with '10', and there are no 3.10 or 5.10 gears...Its probably safe to say that you have 4.10's.

 

Jack truck up spin the tire and count the number of drive shaft rotations to 1 tire rotation 3 3/4 drive shaft rotations would be 373 A lil over 4 would be 411s

 

So after scouring through numerous threads and doing multiple searches I found this thread again.

I looked up the code on my door and discovered it's C3 which as I understand is 4.30
However after doing the vin look up (screen shot attached) it says, if I'm understanding this correctly that I have 3.73 gears. But on the 2nd screen shot it shows several different possibilities.

If my Ex has 3.73s I'm definitely going to have the front and rear regeared. I was comptemplating having her regeared if she had 4.30s to 4.80s
all seeing as how I'm running 315/75R 16 BGF ATS.

I believe she has the 4.30s because at 65mph (using GPS speed tracking) she's right at 2100 RPM in over drive.

ANY incite in this to help me figure out what exactly I'm working with will be greatly appreciated.

Lastly what's the difference and over all benefits of a full floating axel vs. a semi floating axel (if I'm saying that correctly) ?

This is an area I don't have much experience in aside from breaking them in my old '83 Ford F150so 9 inch rear.

 

According to the sticker it has a 4.30 limited slip rear end here is a better vin decoder the one on this site sucks. Of course that doesn't mean that some one couldn't have changed the gears at some point. Sounds like 4.30s though from where you say the rpms are at 65.
https://www.etis.ford.com/vehicleReg...45004.fcvas511

 

Your EX has the 4.30 gears based on the door sticker pictured and your RPMs at 65 MPH with the nearly 35" tires. . With the taller than stock (31.6") tires you have, your effective ratio is now very close to the standard 3.73. The combo of 35" tires and the deeper 4.88 gears will give an effective ratio of 4.30-ish, a great ratio for the V-10 as the additional revs gets the motor up where it not only makes more power but is also more efficient under load. I saw a 20% fuel mileage increase while towing heavy when I swapped the 3.73s for 4.88s. . Much better all round performance too, should have put the 4.30s behind all the 6.8s.
The VIN decoder is showing the standard gear ratio of 3.73, your 4.30s were the optional choice ( better choice). The section where you have the "?" Is showing the various ratios of each gear in the 4R100 overdrive transmission. The area that you have the box around shows the 3 axle ratios available in the EX platform, only the V-8s got the 4.10 as far as I know. The spring capacities shown are correct for a V-10, each motor had different front spring capacities based on engine weight but all of the EXs had the same rear springs. The listed axles capacities are incorrect for the front axle, I think the number should be 5600 lbs (I could be little off on the Dana 50 rating, but it's not 9900 as listed) but the rear number looks right.

 

Thank you greatly WE3ZS!!!
You helped settle the debate I was waging in my head over this.

I'll definitely be upgrading to 4.80s down the road, especially seeing as how the wife has started hinting around that she'd like to get a travel trailer sometime.

With upgrading the gears to 4.80s, that'll effectively change the cruising speed RPMs of the motor if I'm not mistaken. That'll bring em up to or about 2500 RPM +/- correct?

Reason I ask is for fuel mileage. With my current setup up I'm squeezing out just over 12 mpg. that's with the CC set at 65 (by GPS speed tracking ) and my RPMs just a Lil above 2k.

I'm curious as to how 4.80 gears will affect that while not towing as my Ex is a daily driver.

Again thank you for everything.

 

I hardly do any daily type driving in my EX these days, it now serves as our dedicated tow rig for the big TT. Back when it was all still totally stock we pulled a 9500lb toyhauler and were getting 6.5/7 MPG on trips from home around Philly to SC. With the change to the 4.88s on that same trip route, at the same speeds and with the same trailer the mileage jumped up to 9 MPG with no downshifting on the rolling hills on I-95 through MD and VA, the 3.73s would have it dropping out of OD if we ran over a shadow.
The only long distance run I've made in the current configuration without the TT in tow was from home to Savannah GA, along the same route as above basically. With the cruise set at 65 MPH it logged 12.5 MPG on that pure highway run. On the way home I was towing a '94 Geo Metro on a car dolly (my current daily driver ) and got the same mileage at the same speed.
For the past three years we have been pulling our 41' 11,000 lb TT between 3 and 6 thousand miles a year and typically see between 8 and 9 MPG on our mostly highway trips with a best yet 9.4 coming home from Niagara Falls over the Summer. The addition of Banks headers and 5Star Tunes has helped to push the economy up some. .
When I had swapped in the 4.88 gears I ran 32" tires and using a GPS for the speed and my Ultra-Gauge for the revs I checked the revs at various speeds and then compared them to the revs with the new Nitto 35.28" tires.

Speed...........32" tires..........35" tires
50.................1930...............1720
55.................2075...............1900
60.................2280...............2055
65.................2430...............2230
70.................2595...............2400

 

That's not too shabby honestly.
Eventually my Ex will becomea dedicated hauser and play rig, until then I'm doing my best to keep her alive and running strong.

Would I be correct in that the rear end is a 10.5 Sterling ?

Who did you go through for your 4.88s?

I'll have to have a mechanic shop do the install for the front and rear as I've heard stories good and bad getting those bad boys in making sure that they don't explode in the case after install. I've heard the tolerances are exacting with differentials.

 

C3: 1990/96 E250/350 Dana rear axle 3.54-1 / 1999/ Excursion Sterling 10.50" rear axle 4.30-1 w/a 6,080 lbs. rear axle capacity.

 

My 4.88 axles have their own story, I bought them from a guy in WI after they failed to sell in an eBay auction for $1800. He agreed to my $1500 offer and when I told him I was driving out from Philly to pick them up at his dairy farm he laughed and dropped them down to $1200! So my wife and I had a nice weekend driving date and we got a set of axles that were already setup and broken in for our EX. . But yes, if you have a shop do the gears make sure to find a shop that has a good rep and has done a lot of these axle gear jobs.