Eaton HO72 rear axle

[RPOZ11]

DIY 4X4 14-Bolt Disc Brake brackets
They fit! 😎

[BlueBullet]

Looking good thanks for providing all the information

[RPOZ11]

My pleasure!
I'm learning as I do it all.

Eaton Detroit Locker 225S-10 DL 14- bolt

Need a few weeks to disassemble the ring & pinion assembly, powder coat the carrier, then reassemble with the Detroit Locker.

I will then order new axles made to fit this Locker.
(poor lighting made the image appear rusty)

[Vintage Windmills]

subscribed

[RPOZ11]

Carrier apart :

GM part # :
3934635
GM Parts Catalog shows :
3934634
68-72 Ser. 20-30 (exc. 11,000 lb. axle)
Cataolg does NOT state W or W/O side load bolt

[RPOZ11]

Pinion Support

GM part # :
3843067

[RPOZ11]

YOKE

NO GM part # present

[RPOZ11]

Rotors :
Dura International # BR5523
Studs :
Dorman # 610-194

[RPOZ11]

Just an update.
Working on rear calipers.
Possibly going to look into reproducing parking brake brackets and springs.
Aftermarket new calipers look ok.
The core GM calipers need some attention.
Powder Coating was delayed; so I'm a week behind now.
Once I can get all this resolved I can then order the axles.
Until then, same old slow process.
Never imagined the cost of doing these.
And I have 2 more to do.
More updates to come...

[Shaky]

Originally Posted by RPOZ11

Never imagined the cost of doing these.

Yeah - the price on that bearing kit is eye-opening. I like my HO52, but if it ends up needing too much I might have to consider a 14-bolt. Nice work - following with interest...

[RPOZ11]

Well I'm into it deep now.
Goal is to complete it.

Powder Coating :

[RPOZ11]

Side Load Bolt :

[RPOZ11]

So here we have my 14 Bolt axles out sitting side by side as an example of the length comparison/differences.
17-30 spine difference.
Length difference using a straight edge of a bar to show how close they are & how I need to order shorter axles so that they dont hit or become a clearance issue.
Once I get the ring & pinion back from being assembled, I will then discuss further what is necessary with the axles.
Bear with me.
This will take a few weeks to finalize this all.

[Shaky]

Originally Posted by RPOZ11

Well I'm into it deep now.

I hear you. I've spent a lot of money with less to show for it. You're gonna end up with a nice piece (or three).

[RPOZ11]

This one isn't mine but a similar rear disc swap.
With the vented rotors, the rotor outside diameter was a small bit too much from the manufacturer.
What was happening was that the rotor was slightly hitting the caliper pin.
His remedy was to take off ONLY enough material to keep it from hitting.
In the image below, you will see that he took off more material than was needed but leaving enough surface area to show full contact of the brake pads.

Just an FYI; but I thought it was worth sharing.
Maybe not all rotors have this problem.

[Shaky]

Thanks for the update. Can't wait to see this finished.

[RPOZ11]

I'll get there.
Had a few expenses slow me up.

When we installed the Timken Bearings,
The 388 race was miss-boxed.
It had a 382-A 14 Bolt race inside the 388 box.
Luckily I had new Timken Bearings present to cross reference this.

So good to check and double check these things

[RPOZ11]

Finally getting ready to order up axles for this.
Below in the image are the numbers I determined for the factory dimensions.
I did measure the depth that the 17 spline axles have.
Installed, taking into account the 17 spline locker, you are left with a maximum 5/8" clearance before the axles actually touch.
I compared my 14 Bolt axles at where they are splined to the original 17 splined axles and both appear to have similar diameters.
The HO72 axles were about .025 larger.
I went with the 14 Bolt size because I am using an Eaton 30 spline locker designed for the 14 Bolt axles.
The 14 Bolt axles were 1.500.
Add:
Axle flange thickness : .390
Axle bearing landing where hub bearing rides : 1.440
I hope these are all correct.
To be splined for 30 teeth.

[RPOZ11]

Axles arriving today
I'll post pics of these asap

[RPOZ11]

Done

[Asshat]

Originally Posted by RPOZ11

Just picked this up
HO72 Detroit Locker rear axle
Drum to Drum
Here is the code and tag from it
Can anyone decipher the stamped code?
R JJG0761

Tag has no info on it

Hey, I’m a real noob to these rear ends... I thought the Eaton posilock rear ends were all geared real low, I know mine is. What is the desire to have these in your truck? I thought the Dana rears were a better choice since they are geared taller.
Thanks - hope this isn’t a stupid question. I would be willing to sell mine; hoping I can do that once I get this baby on the road.

[RPOZ11]

Originally Posted by Asshat

I thought the Eaton posilock rear ends were all geared real low, I know mine is. What is the desire to have these in your truck? I thought the Dana rears were a better choice since they are geared taller.
Thanks

They are geared low.
I believe mine is a 4:11.
Originality.
Decided to run the HO.
(I have an extra HO drum to drum)
Gear Vendor will assist in my highway mileage ; but probably not enough.
I think there was a 3:90 gear GM offered; or something like that.
Can't recall the 3 series ratio.
Very hard to locate those.

I have a 14 Bolt that I considered using.
3:42 posi in that one.
Just need to move and install spring pads correctly onto it in order to use that one.

[Asshat]

Originally Posted by RPOZ11

They are geared low.
I believe mine is a 4:11.
Originality.
Decided to run the HO.
(I have an extra HO drum to drum)
Gear Vendor will assist in my highway mileage ; but probably not enough.
I think there was a 3:90 gear GM offered; or something like that.
Can't recall the 3 series ratio.
Very hard to locate those.

I have a 14 Bolt that I considered using.
3:42 posi in that one.
Just need to move and install spring pads correctly onto it in order to use that one.

I also read somewhere that they make the tires chirp when turning, is this an issue to be concerned with?

[bry593]

Lockers will make noise, cause poor handling (understand) and accelerate tire wear. They are a terrible addition for a street driven truck. On the other hand, if you use your truck as a truck, towing things and hauling through fields and mud, a locker is a blessing.

For good handling on street you want limited slip (actually does slip). These never lock completely and one tire will usually spin faster than the other. These are a best fit to most motorist driving styles. These are not available for HO52/72.

[Andy4639]

Hello RPOZ11,

I'm loving the info you have posted here. I have this same rear end in my 67 Ramp truck. Per say by the numbers you posted, except mine has no tag with it.
I'm trying to decide which way to go on the rear E brakes. I have none of the parts for them for it. I'm guessing from your info finding them will be a job in it's self.
With that being said do you have the info for the disc brakes you used and do you know of any full kits with the E brakes as well. I know you posted about making up a E brake spring. Any and all info is appreciated on this. Thanks