How do I find out what rear axle is in my truck? 1984 F-250 4x4 8600GVW, it has full floater axles - Pull 8) 5/8 headed bolts from the center and pull the axle out, wheel still on. 30 Splines axles. The cover has 10 bolts and the ring gear has 12.

The tag has rusted gone.

The ring gear says "2 2684 Dana D 32503 A3U172 46-13"

13/46=3.538 ~ 3.54:1 Ratio

Randy's Ring & Pinion says the 32503 is a gear set number for a Dana 60.
Both my local parts stores say the Dana 60 in that year were Semi floaters(C-clip inside). And if it has a full floater then it must be a Dana 61 or Dana 70.

How can I tell?

Shawn



I didn't put this in the axle forum yet because I thought to go truck specific first.

 

im no expert on this by any means, but i have a 1984 F250 2WD and i have a DANA 60 with 3.54:1 gear ratio. if i had to guess, i would say you have the same.

 

Without deciphering the axle code #'s, Dana 60's in the 80-85.5 trucks were the weaker semi-floater versions.
The HD Dana 61 and 70 were the full-float versions.
If it has external structural webbing, it's a 61.
If it has no structural webbing, however it is sort of bulbus looking, it is a 70.
Steve G.
PS Got a picture?

 

I have a Dana 61 in the backyard . I bought it from a local junkyard was told it came from a 85 F 250 it is a full float & has 61 cast into the webbing . These axles have same cover as a Dana 60 but take other internal parts . The lowest ratios i have been able to find for this are 4.56.

 

Well I have it apart and finally cleaned out from the gernaded pinion and ring- bits and pieces. There was a lot of debris. I cleaned for four hours went through five gallons of mineral spirits. But it passes the wet white wipe rag test.

Now that it is clean, I measured up the old shim packs and just became familar with the different shim packs and their function. Which brought me across setting the pinion depth. The Nominal Asssembly Dimension is the distance from the flat end of the pinion to the center line of the axles and ring gear.

I'm using a '79 Ford service manual for a dana 60,61 & 70. It states the nominal assembly dimension is 3.125" for the Dana 60 & 61, The Nom Assmb Dim for the Dana 70 is 3.500". The Nominal Assembly Dimension for my '84 axle is 3.125". So it's not a 70.

8 Lug, It does have webbing on the outside edges, but not over the top like I have seen some 9" housings.

Krick, The webs are pretty rusty and packed with grime. But I might clean those out to look for the 61 in the casting.

I should have the pinion depth and preload set tomorrow night.