rear axle ID #'s
 

I have a 77 F250 camper special 2wd 460/C6 that i robbed the rear axle out of to put in my 71 F250 hiboy that i keap breakin ring and pinions in. I thought both were dana 60's but the axle out of the 2wd is much beefier. The diff housing is much heavier especially. the one out of my 71 says dana 60 and the numbers C-30255 on the housing. the one out of the 2wd has a big # 7 on top the housing and the numbers C-37717. The spring perches are about 5 inches wider on the 2wd axle also. Im hoping but doubting i have a dana 70 but can anyone tell me based on the info i have? thanks

should i move this to the axle forum?

Is there a tag on it? What's the gear ratio? If it's a 3.08, 3.30 ratio it could be a Dana 61. Those look beefier than a 60 and have larger tubes. Can't say if it's a 70 without some numbers. It should say either 60, 61 or 70 on the housing. Or, you can get the BOM numbers off the tubes.

On a side note, there is no reason you should be breaking ring and pinion gears.

I agree they shouldnt be breaking like they do and yet my 3rd set is about to come apart. I know the gears are being installed correctly but ever since the bigger motor and tires that old style 60 doesnt want to hold up. AS far as numbers, i already posted the numbers that i see on it. its pretty dirty but i will try to clean it up and find more numbers. In addition to it being bigger, the spring perches are 5 inches further apart and the shock mounts about 10 inches further apart than on my 71 D60 and the overall width of this axle is 3 inches wider than the 71 as well

There is no way they are being installed correctly. The axle shafts are TINY. A 7.5" Ranger axle has stronger shafts. Even with 35 spline chromoly shafts, the axles will break first. If you can't find any more numbers, look at the cover. On a 60, the bottom of the centersection closely follows the cover. A 70 uses the same cover. However, the centersection will stick out about an inch farther than the cover at the bottom.

The spring pad width is due to the frame width difference.

the 2nd set most likely wasnt right because i didnt know what i was doing then but the first rin and pinion had never been apart from the factory, they were installed right then i broke those, the set i have now i had done about 5 years ago and were installed by a mechanic i know and work with who does this for a living and i watched do it, shimmed it until the gears made contact on the right spot on the teeth i dunno what this process is called im not a real experienced mechanic, but they were right and now they are vibrating like crazy. And ive been through plenty of axles too and ya they normally go first. I know a couple other guys with the same axle who have had to replace gears and axles when they moved up in hp and tire size. I should add that this pickups a toy that i drive more like a quad so its not like normal hiway driving is whats breakn my axles. Anyway i wasnt tryn to argue with u i appreciate the response i just dont see any other numbers on this other axle. its got some surface rust on it and its dirty so they may be hiding. I dont think its a 70 tho, saw a pic of a 70 and the drums on it looked larger than what i have

i have this same number on my axle and was wondering what it is i have also found this number on the axle tubes 603322 3 does anyone know what this came off of i am trying to rebuild it but am having trouble identifying the axle to get the right parts