Eaton HO72 Tech Thread

[06h3]

Thank you AlxJ64 for your insight. It does make me feel better knowing that it seems like the failure was due to cause and effect on hurt parts vs me exceeding the physical strength of the Eaton Ring and pinion. I had a hurt carrier bearing allowing odd pattern wear. It further proves the point that I had another carrier in the axle with new carrier bearings when I installed it in 2016. When I switched the 14 bolt locker setup, I didn’t reuse that carrier. It was easier to setup a new locker with an existing carrier I had laying around then to pull it all apart and wait for the machining on locker/carrier parts, the carrier I put in had those old carrier bearings.

I have more 5.14 gear seats. I’ll work on getting a new one swapped in.

 

[06h3]

This solidifies the failure point to a carrier bearing in my opinion.

I haven’t seen what load bolts look like on race cars but in my mind a load bolt should wear evenly as the ring gear presses against it during deflection.

The pics are tough to see but in person it’s easier to capture. The groove on the top part of the load bolt, that’s not a single groove, everything to the top of that “line” is worn higher than everything below the “line.”

The other pic doesn’t really do it justice but imagine an ever so slight angle worn the entire way up to the groove.

So that carrier bearing was allowing the ring gear to deflect not just away from the pinion tooth in a normal deflection pattern but also in a side loading pattern.

Unless uneven load bolt wear is normal

 

[AlxJ64]

This solidifies the failure point to a carrier bearing in my opinion.

I haven’t seen what load bolts look like on race cars but in my mind a load bolt should wear evenly as the ring gear presses against it during deflection.

The pics are tough to see but in person it’s easier to capture. The groove on the top part of the load bolt, that’s not a single groove, everything to the top of that “line” is worn higher than everything below the “line.”

The other pic doesn’t really do it justice but imagine an ever so slight angle worn the entire way up to the groove.

So that carrier bearing was allowing the ring gear to deflect not just away from the pinion tooth in a normal deflection pattern but also in a side loading pattern.

Unless uneven load bolt wear is normal

Agreed, and it makes sense too with the pics of the load bolt. The ring side bearing was worn and allowing the carrier to pitch. The side gears were holding things lined up and using the moment of the axle shafts to keep things somewhat in place, and the Load Bolt would step in some too it appears. Yea, that carrier was bouncing around in there and the pinion finally ran off the ends of the teeth under some hard loads and snap crackle pop.

Build the next one and keep on runnin!

 

[06h3]

Building the next one now, pattern has been tough to get. I’ve never had to mess with pinion depth on an HO72. They seem to just line up. This one may be different

 

[06h3]

AlxJ64 have you set up gears on an HO72 before? It looks like I should be adding pinion shim to pull the pinon away from the ring gear right?

The drive pattern looks ok (may needs to go a hair deeper into the root) but the coast is wonky.

 

[M92PV4U]

Interesting Craigslist finds

Sorry, no proper link. Enjoy anyway. Here, have a link since its an R :flipoff2: Arse needs a backhoe. John Deere Backhoe 8 mounted on Geo Tracker. Backhoe has subframe mounted/ bolted to Geo Tracker frame.Backhoe works and operates fine. Geo Tracker runs fine, has soft breaks needs new...

irate4x4.com

AlxJ64

06h3

 

[06h3]

Thanks, I’m a bit too far for that. I found one 300 miles from me. Just gotta get up there to get it

 

[AlxJ64]

Interesting Craigslist finds

Sorry, no proper link. Enjoy anyway. Here, have a link since its an R :flipoff2: Arse needs a backhoe. John Deere Backhoe 8 mounted on Geo Tracker. Backhoe has subframe mounted/ bolted to Geo Tracker frame.Backhoe works and operates fine. Geo Tracker runs fine, has soft breaks needs new...

irate4x4.com

AlxJ64

06h3

Little bit of a hike for me but if I end up in that direction I might see about grabbing it.

 

[Spadercr]

-14 bolt axle shafts and the drop in (detroit, grizzly) locker fits in the HO72. There are some exceptions, on some older open carriers they are a tad narrower and do not let the 14 bolt locker unlock. Some have fixed this with washers between the carrier or machining a few thousandths off the side gear. I machined .008 off each side gear for a total of .016 and it now locks/unlocks like it should.
-

Could you tell me if these are the two faces you took .008 to get a locker in your ho52? Or is only one face needed to be machined?

 

[06h3]

Just PMed you