Very interesting Eaton info

[Yukon Jack]

I was reading a post where a guy "hardcore" posts some links to another site about Eaton axles and I found the links have great info. Was very suprised to learn the detroit locker for a 14 bolt can be used in the Eaton if you change axle shafts.

Here's the link, scroll down to member hardcore's reply and review the links he has pasted. http://coloradok5.com/forums/showfla...t=1#Post928445

[BLAZERMAN]

I'm saving those links! its hard to find good info on the Eatons, I know the 14 bolt Corporate is the only axle that you can put a detroit locker in without changing the case making it alot cheaper to add than other axles.

[1969 GMC]

i really want to get an eaton with a locker for cheap traction!

but i saw 2 different axles mentioned in those posts...one with a 10.5" ring gear, and one with a 12.5" ring gear...which one came in 67-72 (and earlier) light chev & gmc trucks?

[Vince M]

The 10.5" is a 14 bolt. The Eaton had a 10.125 if I remember right. Don't know about the other one.

Thanks for the link..!!!

[1969 GMC]

I'd be really curious to see if anyone has actually done that 14 bolt axleshafts mod...seemed like all those guys had heard of it, but none of them had done it.

[K5KRAZIE]

Give me some time. I have almost all the parts to do it. Just waiting for some more and some time...

[72MARIO]

Oky are you saying that if I have a eaton rearend with a detroit locker I can put the locker in a 14 bolt corp ?

I think that's what you said...

That would be Sweet.

[Yukon Jack]

Actually, what I understand is the opposite, you can put a 14 bolt's locker and axle shafts in an Eaton. A locker is not produced now for the Eaton so this is good info to know. If my Eaton or it's locker ever break, I'm not sure I would go this route, but sure good to know.

[72MARIO]

I dont have the time to read up all of the post right now. But the reason i am asking is that I am going to get a practial truck from the 73-87 area one that I can afford the parts. I have a 71 Eaton with a Detroit Locker. I am hoping that it will fit in a 14 bolt rear in a 73-87 3/4 or 1 ton truck.

[Yukon Jack]

Have you considered just swapping over the whole Eaton axle? The 14 bolt is very heavy and the Eaton is as strong or stronger than the 14 bolt, plus it doesn't hang down as far. If the 71 Eaton axle is in good shape, I sure would give consideration to just putting it under the 73-87 truck.

The links above said you have to shorten the 14 bolt axle shafts to put them in the Eaton - so I'm guessing it won't work as it sounds like the Eaton axle shafts won't be long enough to work in a 14 bolt axle.

[1969 GMC]

some board members said it is prohibitively expensive to get new bearings for the eaton axle, but the guys on those pages seemed to have no problem.

[K5KRAZIE]

Spring perches on the 73 and up are a different width. The bearing kit can be had for around $250 max.

[67cst]

kinda weird reading all these replies when my last name is eaton...some funny things come up if you think of it in a different way....yukon...you can put a 14 bolt's locker and axle shafts in an Eaton..maybe so but not this eaton!!!!

[sakohntr]

Board member david passmore HAS HAD THIS DONE. He mentioned it a while back. He could answer any of your questions. I think the eaton case with a detroit locker is the way to go. You get the best of everything....

[Yukon Jack]

sakohntr - that's good info - hopefully I will never have a problem with my Eaton, but sure is nice to know there are some options out there.

67cst - that is funny!

[Mike C]

Hey Mark, you should work a deal to buy a 14 bolt detroit locker and swap for the Eaton one for your truck. No axle shaft changes needed! Coincidentally... I happen to have a 14 bolt detroit for sale... It has been installed in an open diff case, but never been used! I'll take $300 plus shipping for it if anybody is interested. I also have a Dana 60 trak lok for 3.54-4.10 gears and 30 spline axles for $150 plus ship if any interest.

[Yukon Jack]

I'd be all over that, but luckily factory set me up good

[Canadian694x4]

were is that sticker placed Yukon?

[Rod]

On my parts 70 chev sub the sticker is above the mirror on the roof... and on my 70 gmc sub its above the jack in the rear on passenger side.

[jorgensensc]

I could never understand all of the rear end gibberish. Can someone please post pictures along with explanations for the different diffs. Please!!! I don't understand a corporate from an eaton or a floater vs non floater. The only theing I really understand is 10 bolt and 12 bolt. I'm still grasping the whole posi is the same as limited slip concept, because for years I thought they were similar, but still different. Come on now, Hook a brother up!!!

[1969 GMC]

Originally posted by Rod
On my parts 70 chev sub the sticker is above the mirror on the roof... and on my 70 gmc sub its above the jack in the rear on passenger side.

When did you get a new Burb???? I must have missed it. And its a GMC too

[JIMs70GMC]

jorgensensc, I have a copy of the dana 60-70 powr-loc manual in the link in my signature. That'll be a start.

[1969 GMC]

jorgensensc- I will try to explain some. here we go:
the rearend in question here is the eaton ho52 (3/4 ton) and ho72 (1 ton) axle. sometimes incorrectly referred to as "10 bolts" because they have 10 bolts holding the diff cover on. they are basically the same, but have different sized brakes. they have dropout third members like a ford 9 inch.
these axles came in some 3/4 and all 1 ton trucks 67-72, and all 3/4 and 1 ton trucks befor that, IIRC. here is a pic:


Next is the dana 60. this axle came in some 3/4 ton and some 1/2 ton 67-72 trucks, as well as some Ford and Internationals. This is the rearend that is always found behind a BB 3/4 ton truck. Also, it is predominant in GMC's. the version in the 1/2 ton trucks is semi floating, which means the axleshafts are held in with c clips. the 1/2 ton version also only has 6 lugs, while the 3/4 ton full floating version has 8. the semi floating design is weaker than the full floating type, but all 1/2 ton rear axles are semi floating. another easy way to tell is if the axle has a hub sticking past the lugs. If it does, it is a full floater. If not, it is a semi floater. The dana 44, 60, 70, and 80 rearends all look pretty much alike, but the dimensions of various components differs. Each should have a number corresponding with the name (44, 70, etc) cast on the axle housing by the diff cover. Also, dana axles all have drain plugs on the diff covers. They also all have 10 bolts holding the diff cover on. Some early 1/2 ton GMC's will have dana 44 rearends. Dana 70 & 80 aren't found stock on any 67-72, but do show up later in GM's truck lineup. A way to diffrentiate the dana 44 and 10 bolt (which both have 10 bolt diff covers and appear similar) are the small "ears" on the bottom of the corporate diff.


Last, the corporate 14 bolt. can also be had in full float or semi float designs. this axle was the replacement for the Eaton HO axle, it first appeared in '73 in all 3/4 and most 1 ton trucks (the dana 70 is sometimes used on 1 ton dually units). the dana 60 was no longer available. in appearance, it resembles the dana units, but it has 14 bolts holding the diff cover on (vs 10 for danas) and doesn't have a drain plug on the diff cover (it's on the side of the axlehousing). this axle is big and heavy, and is very popular with the offroading crowd.


hope this helps a little.

[jorgensensc]

1969 GMC,
WOW, I'm going to have to save this page!!! That is really great info, thanks. It's a whole lot to get your head around. Thanks again!!!

[Yukon Jack]

My sticker for my NoSpin is directly under the rear window on the driver side of the cab. My instruction sheet showing shift positions for the Rockwell T221 transfer case is directly above the mirror on the cab roof. On the outside of my glove box door is an instruction sheet giving more info on the front axle.

I've read repeatedly that the 1969's always had the mirrors mounted on the roof, but mine couldn't have been as that is where the factory sticker is for the transfer case shift pattern. When I bought my truck it didn't have a rear view mirror at all.

Just goes to show these trucks were put together by hand and workers did things differently I guess.

1969 GMC great info.