CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Eaton rear axles HO72 ???

tarussell

“Seven years of college down the drain”
 Premium
Joined
Dec 28, 2002
Posts
5,163
Reaction score
11,496
Location
Pensacola , FL
Do the HO72 ( I think that's the number designation ) use a crush sleeve for pinion pre-load ? Just for clarification this is the rear axle that came in 1972 and older 3/4 Tons and has a 10-1/8" R/P - third member style chunk with removeable rear cover .
TIA , Tom
 
1 ton

This rear end should be a 1 ton, the 3/4 tons were a Dana 60.

But, as for our question I have no idea what you're talking about. :grin: Sorry, but I'm new to this differential thing.

However, if you tell me what you're looking for I can go look at the torn apart Eaton in the garage and give you an answer!
 
some 3/4 tons had dana 60's, but most i see have the ho52's. I have a 68 2wd & a 71 4wd both with the eatons.
 
All I can tell you is don't remove the "fill plug" like you think you know about from the 14-Bolts!!!!!

The bolt in that area is for pinion preload (not for gear oil filling!) as I found out the hard way about 12 hours before the last trip to Moab. Fortunately 4X4HIGH was there with an old, crusty shop manual to help me get things reset to factory specs.

The clue should have been that the diff cover has a fill plug in it (unlike a 14BFF).... sometimes I seem to overthink things too much.


BTDT..... :D
 
Greg72 said:
All I can tell you is don't remove the "fill plug" like you think you know about from the 14-Bolts!!!!!

The bolt in that area is for pinion preload (not for gear oil filling!) as I found out the hard way about 12 hours before the last trip to Moab. Fortunately 4X4HIGH was there with an old, crusty shop manual to help me get things reset to factory specs.

The clue should have been that the diff cover has a fill plug in it (unlike a 14BFF).... sometimes I seem to overthink things too much.


BTDT..... :D



I thought the ring gear deflection bolt was only on the HO110 rear ends ??? Do all HO72's come with the deflection bolt ? I have never really looked into these axles , all my knowledge is from what I have read so any help you can give me is a great help !
Thnaks , Tom
 
Well don't take my comments as "gospel".....

The only Eaton I've ever seen was the one in my 3/4-Ton Burb (1972). That's the one I'm referring to, but I don't know specifically which Eaton model it is.

Mainly, I just wanted to give you a reminder to "assume nothing". I took my 14-Bolt concepts and misapplied them to the Eaton and caused myself a couple of extra hours of headaches, and nearly screwed up my departure to BlazerBash 2003. :crazy:

While I'm thinking about it....Eatons have "through holes" from the diff cover into the casting, so you can actually drain the fluid without pulling the cover....just remove a couple of the lower bolts, and maybe one up top (to prevent vaccuum). I had a heck of a time trying to reseal the cover on mine, I used the "real" gasket the first time, then I tried thread sealer on all the bolts, then I finally decided to try that Permatex "Right Stuff" gasket maker product. The pumpkin has been completely dry (on the outside!) ever since. From now on, I'll probably just pull the bolts to change the fluid instead of dealing with that cover again.....




:usaflag:
 
hey Greg, that ring gear preload bolt or whatever you call it, do you know how to set it. I did the same thing you did. i figured that you just check fluid levels thru the same hole you fill thru. I would love to know the correct procedure on how to set the proper load with that bolt. I was guessing that maybe you would torque it to some specified torque like 15ftlbs or some thing. Thanks Todd.:)
 
Actually it's not a preload as much as it is a "clearance"

I think when we set it, the manual said to tighten the nut until it "bottoms" out and then back it off a specified amount (like 1/8th turn?) or something like that....

You'd have to send a PM to Scott (4X4HIGH) and ask him to look up the spec again.....just tell him I sent you, that should help (or not!) :D
 
alright thanks. How do you pm someone like that. Ok stop laughing now, cause i really dont know how to do it:haha: :dunno: :yikes:
 
Upper right corner of your screen "Private Messages".....follow that link and look in the left column for an option to "send message"....

Easier than pulling a fill plug on an Eaton! :grin:
 
Thanks Greg. Then after your in send message mode, i then type in scott something (cant remember what you said & i cant see it right now) then message then send.
 
OrangeCrushK10 said:
This rear end should be a 1 ton, the 3/4 tons were a Dana 60.

But, as for our question I have no idea what you're talking about. :grin: Sorry, but I'm new to this differential thing.

However, if you tell me what you're looking for I can go look at the torn apart Eaton in the garage and give you an answer!


Thanks for the offer to look at your stuff for me . I need to know if the pinion support has a collar that gets crushed between the two large oposing pinion bearings or if it has multiple shims that control pinion bearing preload.

Thanks , Tom
 
OrangeCrushK10 said:
Well, you learn something new everyday. So, my question is - How do you tell the difference between a 3/4ton and a 1ton Eaton?


From what I have learned the 1-Ton's had the 12.?? inch ring gear diamter instead of the 10.125 ring gear . The larger rear has a welded rear cover that does not come off and the HO72 has a removeable rear cover.
I am still trying to learn about these rear axles but so far that has been the easiest way for me to indentify in the bone yards .
HTH's , Tom
 
Dragging up a HORRIBLY old topic, BUT... its the appropriate thread to continue this in.

Where in sweet chevy loving jesus can I find service parts (shoes, drums, hardware kit) for a HO72? Parts shops I've been to don't even seem to know it exists. And if anyone knows of a service manual, or a haynes or chiltons that covers this axle, what is the model & year & publisher of the book so I can try and dig up a copy somewhere?
 
I spoke way too soon. Seem to have found the parts from Checker, but they're ludicrously expensive. Guess when it needs brakes, it'll get a disk swao,
 

Latest Posts

Top Bottom