GM's Eaton Rearends

[Rot Box]

Do any of you know anything about the rear ends used in the 72 and older GM 3/4 and 1Ton trucks? I know that they where made by Eaton, and had full floating axles, a dropout third member, and there where also many ratios offered from 3.90's to 5.13's. And supposedly they where also offered with an old school Detroit Locker...

What I'd really like to know is what width from wms to wms was offered, what the pinion shaft diameter is, and also how many splines the axle shafts have. Any info would be greatly appreciated

 

[DaveB]

The axle that was in my old 72 Chev 3/4 was an Eaton HO72. It was a stout axle that didn't give me much trouble. The width was pretty much stock full width but since I don't have it anymore I couldn't tell you the exact width.

 

[BCGPER]

Can't give you exact numbers, but the ring and pinion are huge. The weak link in stock form is the axle spline is very coarse. I'd guess something like 12.

 

[I Lean]

You can shave the bottoms of 'em for a ton more clearance, and apparently you can use FF14bolt side gears in their carriers to get better/more available shafts. Scott @ Rockstomper ran one a few years back, might give him a call for actual info.

 

[Rot Box]

Thanks for the replies

I like the FF and dropout third design alot, and I think that I'm going to pick one up in the near future to tinker with. I'd like to find one with 5.13's and the factory locker, and from what I've heard that shouldn't be too hard. Guess I'll see what happens

 

[jsudar]

Digging up an old thread... school me on eatons

Do they share any parts with the 14 bolt or are they a totally different animal?
Are parts still available?

And finally, has anyone seen one for sale lately or in a wrecking yard? All the yards I frequent don't have anything like that.

 

[Chevycrew]

I know where there are a bunch of eatons, just depends what you want, width, gear ratio etc.

Parts are rare, 14 bolt is different. 14 bolt locker and shafts will work with some work (according to the web)


My buddy has one from a 68 2wd chevy that is 4.10 and 65" wide and 8 lug, that he is using under his jeep.

 

[Tacoma]

If you've got one laying around, they might be worth using, but for the cost of 14bolts, I wouldn't personally bother.

 

[jsudar]

The reason I'm interested in them is for front axle purposes.

 

[Rot Box]

Wow it seems like forever ago since I posted this thread

After a ton of searching i came to the conclusion that a 14 bolt is the way to go. In the long run the only real benifit to the HO72 is being different :-\

There was a tread on Pirate awhile back about an Eaton front axle--I'll try to find it But imo building a D60 front would be a lot less stress plus you can find parts at places like Wal-Mart

 

[ricsrx]

I have one of those in my back yard, been dragging it around for 15+ years thinking i was putting it in my 72 4x4 for a 3/4 upgrade, are they worth any thing, i dont know if it has a locker or what gears. posibly for sale, also a front axel i guess its a d60.

 

[Gravy]

should be 19 spline coarse.
theres a dude on NAXJA (MacGyver) that is running one in his XJ buggy thing. with a no-spin (detroit) and 5.13's
I'd personally love one, the housing looks so much lighter than a 14 bolt

 

[Tacoma]

I'd personally love one, the housing looks so much lighter than a 14 bolt

It's not that much lighter...

 

[Kiel]

It's not that much lighter...

But their round, it makes it better then the damn triangle ditch digger

 

[Tacoma]

Bigger tires, more HP.

 

[jsudar]

It would be cool if there was aftermarket support for these axles. It seems to me that they have all the benefits of the Ford 9" (dropout third, easy to setup gears, sheet metal housing, three pinion bearings) but with a bigger ring gear.

Chrisman makes 10" ring gears that fit in custom 9" style third members, but it would have been less work to build off the existing eaton architecture instead of using custom 9" stuff made bigger.

I've been thinking too much again. The ideas won't stop... I'm on a mission mainstream the HO72. It'll be the next dana 60. Now, if someone will lend me a few hundred thousand for start up capital, I'll get this show on the road and lose all your money building a business around an axle no one cares about.

 

[Gravy]

so I lied they are 17 spline. 1.75" diameter at the splines and 1.5" diameter shafts

but they are tons lighter than a 14bolt.
with drums I can pick up one side of an eaton.
last time I tried that with a 14bolt, even without drums... I almost crapped my pants.

 

[Kiel]

so I lied they are 17 spline. 1.75" diameter at the splines and 1.5" diameter shafts

but they are tons lighter than a 14bolt.
with drums I can pick up one side of an eaton.
last time I tried that with a 14bolt, even without drums... I almost crapped my pants.

Yeah almost Maybe your just getting stronger