Everyone now is used to newer cars and trucks, and all of them have overdrive. You are going to find your 3.50 rearend is going to rev the engine a little higher than you are used to on the highway. It's a good all around gear for towing and everyday use, but it's a little high for a long trip on the interstate. Like I said though, back in the day it was a fairly common gear and worked well when the speed limit was 55.

 

Thanks for the info. I haven't actually driven this little truck yet - we brought it home on a trailer and parked it for a week. I went out to start it & it nearly caught fire - smoke billowed from under the hood & the cab had enough smoke to choke a camel. I disconnected the battery quickly & checked out the engine compartment while my mechanic apprentice daughter aired out the cab & searched for the problem under the dash. Turns out, whoever installed a couple of after-factory gauges did a horrible job on the wiring. We melted several feet of heavy wiring & nearly lost a sweet truck because of sloppy connections. We removed all the offending wiring yesterday & we'll clean up the remaining connections today.
I've checked out most of the little truck - body is in good shape for it's age. Tranny seems good; engine, brakes, u-joints, rear pinion seal...all need to be rebuilt/repaired/replaced.
Having a mechanic apprentice peering over my shoulder definitely comes in handy. I'll still be bugging all you good folks for pointers now and then.

 

Can you determine the spline count with the axle code as well? I have an 86 f150 with axle code 18 so it's a 3.08 8.8 but I'm trying to upgrade and need to know the spline count.

 

Tgore3, I can verify C9, 3.55ls - 97f350, 35, 4.10 - 86 f250, C5, 4.10 - 86 f250 and 29, Semi float 3.55 open - 87 f250

All trucks I own or owned and verified myself.

 

The Certification Label AXLE code cannot be used to determine the spline count. 1983/89: 18 only decodes to WDR 8.8" 3.08-1 without Limited Slip, 3,750 axle capacity.

The rear axle ID tag is what is needed to determine the spline count. The code is used to find the correct axle shafts in the parts list.

Once the part number is known, one has to look for that part number in the rear axle ID chart to determine the spline count. It's a PITA, but it's the only way it can be done.

'Course, you could pull the axle and count the splines yourself...and if the rear axle ID tag is missing, this is the only way to find out.

Left (upper): 1983/89 F100/150 WDR 8.8" w/o Limited Slip - parts list #236 - axle is basic part number 4234. Notice all the different suffixes for the WDR prefix.

Right and Left (lower): Axle ID chart.

 

so the axle tag thats the info stamped into the housing right? Just to the left and on the upper portion of the shat connection.

e4tw-a1a

 

Nvm I did find the tag it was still there woot lol.

s806a
308 8 8 6d18

 

Hiyas! Long time no been around.. No money to spend on the truck..

- but just ran into a parts truck and wondered if anyone could decipher this one for me. I *may* have left part of the tag on the rear end.
Looks to be a 9" - and here's what I have:

WDM DC 1C16
47 9 S322B

Anyone? It's in a Canadian-built '81 F100 that was a 300 with 3-on-the-tree.
Cheers!

 

Look at the mfg sticker on the door frame for the 2 digit axle code or on the unit itself for the tag.
There is no mistaken the 9" it does not have a cover on the back it's repaired from the front. The tag may be covered in gook and need to be cleaned off. I recommend engine degreaser.
Good luck and cheers!

Just re read about the tag. Sorry bout that.

Here are the door codes you need.

Rear axel codes.

Ford Rear axle codes used from 1981-1986
13- Ford 9" 2.75 ratio 1981-83
13- Ford 8.8 4.11 ratio 1985-86
H3- Ford 9" ls 2.75 ratio 1981-82
H3- Ford 8.8 axle 4.11 ratio with limited slip 1985-86 (3800 pound)
14- Ford 9" 3.00 1981-1986
H4- Ford 9" 3.00 Limited slip diff 1981-86
15- Ford 9" 3.25 1981-82 and 2.73 in 1983
H5-Ford 9" 3.25 limited slip 1981-82 and 2.73 in 1983
16- Ford 9" axle 3.50 ratio (3750 pound)verified
H6- Ford 9" axle 3.50 ratio with limited slip (3750 pound)verified
18- Ford axle 8.8 3.08 ratio (3800 pound) 1983-86verified
H8- Ford axle 8.8 3.08 ratio limited slip (3800 pound) 1983-86verified
19- Ford axle 8.8 3.55 ratio (3800 pound) 1983-86verified
H9- Ford axle 8.8 3.55 ratio with limited slip (3800 pound) 1983-86verified
23- Dana 60-3 axle 3.54 ratioverified
24- Dana 60-3 axle 3.73 ratio verified
29- Ford Semi Float Sterling 10.25, 3.55 ratio
B9- Ford semi Float Sterling 10.25, 3.55 ratio limited slip diff
B5-Ford semi Float Sterling 10.25, 4.10 ratio limited slip diff
39- Ford full float Sterling 10.25 3.55 (single rear wheel)
C9- Ford full float Sterling 10.25 3.55 (single rear wheel) with limited slip diff
35- Ford full float Sterling 10.25 4.10 (single rear wheel)
C5- Ford full float Sterling 10.25 4.10 (single rear wheel) with limed slip diff
33- Dana 61-1 3.54 ratioverified
C2- Dana 61-1 3.54 ratio with limited slip diffverified
52- Dana 70-1 HD 4.10 ratio (8700 rating)verified
53- Dana 70-1 HD 3.54 ratio from 1983-86 (4.56 in 1982) (7400 rating)verified
E2- Dana 70-1 Hd 4.10 ratio with limited slip diffverified
49- Ford Sterling 10.25 dual rear wheel 3.55 ratio (7400 rating)verified
D5- Ford Sterling 10.25 dual rear wheel 4.10 with limited slip diff (7400 rating)
69- Ford Ford Sterling 10.25 dual rear wheel 3.55 ratio (8250 rating)
F5- Ford Ford Sterling 10.25 dual rear wheel 4.10 ratio limited slip (8250 rating)

 

WDM-DC = Ford 9" 2.47:1 non-locking hypoid, came in both 2.8M and 3.75M capacities 1980/86
1C16 = build date of March 16, 1981 (assuming this is an 80s generation truck you found this on)
47 - the "2" is likely covered up by the bolt; this is the ratio
9 = ring gear diameter
S322B = Production Plant code

Source: FoMoCo 1980/89 Light Truck Master Parts Catalog, available on cdrom from hipoparts.com

 

Oh, yeah! :-) - so this means it's a true highway geared third member? Good deal..
Now - do I have it hauled here to part out/scavenge off of? - or just strip what I can use and let the guy scrap it @ $190/ton? Hmmm... He had really been replacing parts on it too. New shocks, bushings, brakes and lines, etc. Really rust-free frame and supports and such as well.
- but like I have time for ANOTHER project around here.. :P

Thanks guys! Never knew there was a 2.47 out there. Don't see it in the usual list ghost up there posted...

 

Trucks have 31 spline axles and cars have 28.

 

See the charts above.

 

Today I just acquired a 81 F100. The rearend looks like it could be a Limited slip. But there is no tag.
The door sticker has for axle saying G1. I cannot find any reference to that number.
This truck is nearly rust free. Just the trans went and they parked it 4 years ago. I think longer. But a worthy fixer.
I just like to know if I have a limited slip or not and what G1 is.

 

I can't find a G1 in the 1980/89 FoMoCo Light Truck Master Parts Catalog; can you post a picture of your door jamb tag?