Need help with Ring and Pinion Identification

[Tgure]

I picked up this Rear Dana 60 axle from a local junk yard. They said it is out of a 75 F250 4x4. The BOM# is 603381-11 which comes up as a Standard 3.73 out of a 1973-74 F-250 3/4 Ton HD 4x2 Pick-up - Full-Float.

So I don't know anything about axles. But I thought that in an axle without a locker or limited slip if you spin one wheel the other goes the oposite way? Well on this axle the both turn same way and you cannot hold on to one and spin the other.

So in looking at this axle for being out of a 75 it is pretty free of dirt and grime and has a black paint still on it and the ratio tags are missing. So I decided to open it and see if it had a locker or limited slip and verify the ratio. Here is where I am kinda stuck.

On the ring gear is the following numbers:

7676 6 18 96 Dana T32503MAIL 605 46 - 13

So I am not sure if this is actually a 3.73 ratio and this looks like a open diff to me so why do both wheels spin? I don't see any welds on gears or anything.

 

[INPHOBIC]

It's an open diff I can see the spider gears in your photo. Both wheels will turn forward. they do going down the road..... ;D Hold the pinion still and you will see the other side turn backwards. You can count the teeth on the ring gear and pinion and divide. But if the numbers on the gear are correct then it is a 3.50 ratio.
As long as it is not a Dana 61 I would say you did fine.
Either way you will need a new carier for lower gears.
Jake

 

[joser]

The easiest way to find the gear ratio is as follows:

Put a chalk mark (or something like it) on the driveshaft and the tire at 12 o'clock position. If this axle is not mounted, just mark the yoke and the drum. Then, turn the tire (or brake drum) and count how many revolutions the driveshaft (or yoke) makes in the time the tire (or drum) takes to make one revolution. Start with the mark on the tire (or drum) at 12 o'clock, and finish with it at that position.

I have 4.56 gears, so my driveshaft spins a little more than 4 and a half times, to get the tire to spin once.

This method can be done while an axle is in a vehicle, out of a vehicle. You do not have to crack open the diff.

Good luck!

 

[Tgure]

It's an open diff I can see the spider gears in your photo. Both wheels will turn forward. they do going down the road..... ;D Hold the pinion still and you will see the other side turn backwards. You can count the teeth on the ring gear and pinion and divide. But if the numbers on the gear are correct then it is a 3.50 ratio.
As long as it is not a Dana 61 I would say you did fine.
Either way you will need a new carier for lower gears.
Jake

Ok so the last four numbers tell the ratio is 3.54.

I did hold the pinion and I cannot rotate either drum, so something is weird. Oh well if they were 3.7s's I was going to run it for awhile but since it is 3.54 I will just replace everything. ;D

 

[Broncobowsher]

The 6 19 96 is a date code. 6/19/96. The gears are 20 years newer then the axle. The 46 13 is the gear count for the ring gear and the pinion gear. Divide them and you get 46/13=3.5384615384615384615384615384615 or simply 3.54 gear ratio.

Someone in the past ten years has beeen inside that axle and replaced the ring and pinion.

You say both spin. You mean when you turn the yoke (pinion gear) both turn the same direction? That is normal. Try holding one axle/hub/tire while turning the yoke. If you can hold it, it’s open. If the held axle turns no matter how hard you hold it in your hands while turning the yoke then it is a posi, locker, destroyed spider gears.

 

[Tgure]

The 6 19 96 is a date code. 6/19/96. The gears are 20 years newer then the axle. The 46 13 is the gear count for the ring gear and the pinion gear. Divide them and you get 46/13=3.5384615384615384615384615384615 or simply 3.54 gear ratio.

Someone in the past ten years has beeen inside that axle and replaced the ring and pinion.

You say both spin. You mean when you turn the yoke (pinion gear) both turn the same direction? That is normal. Try holding one axle/hub/tire while turning the yoke. If you can hold it, it’s open. If the held axle turns no matter how hard you hold it in your hands while turning the yoke then it is a posi, locker, destroyed spider gears.

Must be destroyed spider gears because I can find no posi or locker in there. ;D

 

[SecondChance]

Guess it's time to rip the guts out and start fresh.