Rear End, What am I?

[ck5566]

Can just by looking at a rear end (3rd member) tell you what it is like a Dana 60,44's, or the standard GM rear ends? And does it matter if having Trailing Arms or with Leaf Springs determine what it is?

[57taskforce]

Your model of truck will help a lot in narrowing this down. If it's a half ton it's likely a 12 bolt gm, but there are some light duty semi floating Dana 60s around. The gm will have 12 bolts holding the diff cover on. If it's a 3/4 ton it's likely an eaton ho 52 which is identifiable by a removable 3rd member. It could also be an hd Dana 60. Both will be full floating rears but only the eaton will have a removable 3rd member.
I don't know as much about the 1 tons but I do know they should have and ho72 which is mostly the same as the 52. I think the Dana 70 was a possibility as well but I'm not positive.
This is all speaking in Chevys. Gmcs primarily with the 3/4 ton trucks had Dana 60s.

[LockDoc]

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The Dana 44's and 60's will have it cast into the rear webbing where the arrow is pointing.... This is a 60.

LockDoc

[ck5566]

Here is mine, if needed I can get more pics. Truck was Originally a 68 C10 6 cyl, 3OTT, coils on all 4 corners. Doing the one wheel up & rotating tire around Twice comes around 3 3/4 turns being a 3.73 ratio.

The truck now has a SBC (305) & 700R4 and a hole lot of PAST OWNERS ideas on what to put on it just to keep it running **THAT** is slowly coming off & going back to mostly a Stock form but "A" (350) will replace the 305 some day.

[CUSTOM/10]

12 bolt

[cleszkie]

GM Corporate 12 Bolt would be my vote.

[cpnbnanamn]

How can you tell what ratio is in it? I've got a '67 SWB with a 6-cyl and 3-ott. I'd LOVE to get more speed out of it. 60 is about all she's got, without over-revving.

[ck5566]

Originally Posted by ck5566

Here is mine, if needed I can get more pics. Truck was Originally a 68 C10 6 cyl, 3OTT, coils on all 4 corners. Doing the one wheel up & rotating tire around Twice comes around 3 3/4 turns being a 3.73 ratio.

The truck now has a SBC (305) & 700R4 and a hole lot of PAST OWNERS ideas on what to put on it just to keep it running **THAT** is slowly coming off & going back to mostly a Stock form but "A" (350) will replace the 305 some day.

Originally Posted by cpnbnanamn

How can you tell what ratio is in it? I've got a '67 SWB with a 6-cyl and 3-ott. I'd LOVE to get more speed out of it. 60 is about all she's got, without over-revving.

cpnbnanamn this is for you! In my 4th post re read how I told how to find out whats the rear gears ratio. If you know for sure that ONLY ONE wheel spins hence NO Posi then here you go. Step 1 jack up trucks pass side axle leaving Drivers wheel ON THE GROUND and draw a line with white chalk on Drive Shafts bottom @ 6 o'clock and also mark the pass wheel at same bottom @ 6 o'clock then turn wheel TWO times around and count how many times the Drive Shafts chalk line goes around. If it goes around 3 times its 3.07, 3.1/2 times its 3.42, 3.3/4 times its 3.73, 4 times its 4.11, 4.1/2 times its 4.56. This method is pretty close for you to get an idea of what you have.

I am betting on it having 4.11's or 4.56's but it also could maybe have had the trans replaced with another or the gears changed out to give you a real STUMP PULLER! Do you go through the gears real fast like maybe close too 10 mph in 1st & 20 mph in 2nd & 40 mph in 3rd ? these are just a guess's for the mph's.