eaton H072

[Odin K30]

Originally Posted by AlxJ64

The fab cover claims no need for a fill plug? That is a LOAD OF SHIT... Is this the Ballistic cover that you are talking about?

That has been corrected.
I worked with Jeff at Ballistic designing that cover (I was the ginea pig)
It does come with a fill plug.

[hmatiak]

Is there not a C&C version of this axle? Got one for basiclly free lastnight. Ill post pics shortly.

[hmatiak]

1/2 inch studs and 16.5 rims



Looks like a 72 to me

[WHITE RHINO]

Originally Posted by blazerboy85

are all the ho72 pinions that big? cus that looks way fucking bigger than what iive got i havent torn into it yet though so idk. how is your eaton treating you? you runnin stock 17 spline stuff?

my axle has held up great, i run stock shafts and a welded 3rd with 44's and no issues. I got it with the disk conversion already done/ planning on shaving it soon

[AlxJ64]

Has anyone broken one of these things? Thats the question. If so, how and under what setup?

And the axle above, it if has 1/2" studs then its a pre- 1970 axle and you can drill out and press the 9/16" studs in.

[blazerboy85]

Originally Posted by AlxJ64

Has anyone broken one of these things? Thats the question. If so, how and under what setup?

And the axle above, it if has 1/2" studs then its a pre- 1970 axle and you can drill out and press the 9/16" studs in.

yea i am quite curious to know if anybody has even broken parts on these axles. ive been looking into my front eaton and the only thing i see that i think will break is the outer shaft because theyre similar to 44 shafts

[Northern Drivetrain]

The closest that I have come is to wear the bearings out after 13 years in the mud with seals that barely kept mice out, let alone the mud. Even with all of the bearing rollers missing, it still didn't break - would just lock up every now and again.

This is with cut 44 Boggers, 4.56 gears, 475 HP (per the dyno) and plenty of air time. I have broken most everything that there is to break on my front 60, but never the Eaton.

[Filthy McChevy]

I put kinks in the splines on the 17 spline axleshafts I had in the Eaton rear out of a 71 Suburban I swapped into my 73 pu with a pretty powerful big block and a 465. That was after years of towing and plowing snow and getting big loads of firewood, while driving like a maniac that almost never got passed anywhere. I swapped them out when I put a no-spin in. Didn't break them though.

[Tech Tim]

Grrrreat tech thread....

I've been trying to gather a bunch of info on these axles, but there is so little out there and even the guys who claim to be experts cannot agree on things, so I'm going to throw some Qs out there, can anyone answer these for sure?

First off, does anyone know for sure which year(s) they were introduced?

I show 1960 for the H-052 and 1955 for the H-072. I believe that is off by a bit, but the books also show a H-033 and a H-050 that were used in the 50's and 60's.

Originally Posted by Odin K30

Only difference between 52 and 72s are the brakes, usually bigger on the 72s and ring gear load bolt found on the H072.

Are you sure on the load bolt and brake size being the only difference? There are some who say they've seen the H-052 with the load bolt.

I've been told that the 052 and the 072 have a difference Pinion Mtg Depth. Anyone have any insight?

Has anyone taken a ring and pinion from a 052 and put it into a 072? or vice-versa?

Originally Posted by 4x4Poet

Any factory overhaul manual for 67-72 chevy trucks will show a section listing both H05272 axles but refer to pics, specs, and procedures for the same 3rd member. The "52" refers to 5500lbs and the "72" to 7200lbs in capacity of some sort.

Does anyone know what capacity this is referring to? The 052/072s are rated at 11,000lbs and 17,000lbs respectively.

I've seen them in the GM manual referred to as a 5200 and a 7200, but no lb. notation afterwards.

Originally Posted by AlxJ64

So as for differences in 052 and 072s... Two major things that I have learned from my research... The 052s do not have the ring deflection bushing.

OK, that seems to be a consensus and it makes sense, the load bolt would give it a higher load rating.

Originally Posted by AlxJ64

however, I did find that in '70 they went from double roller pinion bearings to taper bearings.

The doubler roller bearing and taper bearing have been in use since the 50s was used in both the 052 and 072 axles. I had originally thought that it was another distinction between the 052 and 072 axle, but looking in old bearing books they list either or for both axles depending on year.

The doubler roller brg is BCA# 5310-WA.

The doubler taper brg is BCA# A-1011.



In talking with a few of the 052/072 old timers, they say the tapered brg holds up way better than the roller brg set-up.


Gear ratios? It is known and proven that there are 4.10s, 4.57s and 5.14s; supposedly a GM manual shows there to be a 5.83 gearset. Has anyone actually seen the 5.83s or have a set on hand? Pics or it didn't happen.

Originally Posted by 70Custom4WD

This is some great info for the Eaton axle.

Originally Posted by Filthy McChevy

I had in the Eaton rear out of a 71 Suburban

Calling it an Eaton axle has been a big bone of contention from most old-timers I've talked to. They say that Eaton only built the housing, but Saginaw or GM built the 3rd members, ring and pinions and diffs. They call it a GM axle, not an Eaton.

They've been an Eaton axle to me ever since I've seen my first one, but some people have gotten their panties all in a bunch when I called it an Eaton.

[Davethorik]

Originally Posted by Tech Tim

Eaton

I haven't had mine apart, but I do have a 3rd from a '65 C20 [4.57, No-Spin] and one from a '68 C30 motorhome chassis [5.14, open, load bolt, extra oil passage to the pinion].

The 5.83 gears were shown in a service manual, iirc. i think i have that pic somewhere. yep, here it is...it also lists the 5200 and 7200 as capacities, so who knows? Here is also an exploded view. enjoy

[AlxJ64]

Originally Posted by Tech Tim

Grrrreat tech thread....

First off, does anyone know for sure which year(s) they were introduced?

I show 1960 for the H-052 and 1955 for the H-072. I believe that is off by a bit, but the books also show a H-033 and a H-050 that were used in the 50's and 60's.

For response reasons I am going to refer to the 052s as having the non load bolt and the 072s as having the load thrust bolt.


Don't know for sure the latest date but from personal experience I have pulled the non load bolt "052s", from as late back as a 55, and I have pulled "072s", as late back as '60. Next weekend I am going to snag two more 052s with 5.14s and one is detroited.

Originally Posted by Tech Tim

I've been told that the 052 and the 072 have a difference Pinion Mtg Depth. Anyone have any insight?

Has anyone taken a ring and pinion from a 052 and put it into a 072? or vice-versa?

I have. I took a 5.14 from an 052 and swapped it into the 072. It went just fine, however, I did TIG the oiling port in the 072 third closed as the pinion retaining flange did not block the old oil port. That was easy enough to do and I have had no problems from it. I ended up not using any pinion shims from either case even though the only one I had was the 072 and it was only .020" thick. But I got a great gear pattern out of it and have run it about 1,100 miles on the road and on about 10 wheeling trips with 38" Creepys and have had zero problems from the rear axle other than a weird issue with the hub seal. Thats it.

Originally Posted by Tech Tim

Does anyone know what capacity this is referring to? The 052/072s are rated at 11,000lbs and 17,000lbs respectively.

I've seen them in the GM manual referred to as a 5200 and a 7200, but no lb. notation afterwards.

My guess is GVRW. More so a limitation on the hubs and deflection of the housing than anything. I know the thirds were good up into a C60 IIRC. Correct me if anyone thinks I am wrong. I have in FACT seen these things in the old BIG 6 lug truck pattern as well.

Originally Posted by Tech Tim

OK, that seems to be a consensus and it makes sense, the load bolt would give it a higher load rating.

Thats what I have been basing my input on, even though several folks say its just the size of the rear breaks. Which is possible if the 072 predates the 052 in manufacture date. But then again, maybe the 072 was originally for the DRW options? Strange.

Originally Posted by Tech Tim

The doubler roller bearing and taper bearing have been in use since the 50s was used in both the 052 and 072 axles. I had originally thought that it was another distinction between the 052 and 072 axle, but looking in old bearing books they list either or for both axles depending on year.

The doubler roller brg is BCA# 5310-WA.

The doubler taper brg is BCA# A-1011.

Huh, also new info to me. Thanks!

Originally Posted by Tech Tim

In talking with a few of the 052/072 old timers, they say the tapered brg holds up way better than the roller brg set-up.

Pic looks familiar!!

I would believe that it does. The roller bearing feels like it has a bit more slop in it that the taper.

Originally Posted by Tech Tim

Gear ratios? It is known and proven that there are 4.10s, 4.57s and 5.14s; supposedly a GM manual shows there to be a 5.83 gearset. Has anyone actually seen the 5.83s or have a set on hand? Pics or it didn't happen.

I have a junkyard / collector that I frequent about twice a year and he claims to have two of these center sections in the basement. I have seen them in person but did NOT verify the ratios. I will try to get a picture of the tooth count stamped on the gear next time. He wants a bajillion dollars for them as well. ie, not for sale.



Now... I have a question.

The hub bearings that are in my axle are the original bearings I believe as the races are Cup shaped and the rollers are all very rounded shaped. They seem to be able to run at nearly any point on the race as its bowl shaped rather than a cone shape. Anyone have any input on this and has anyone replaced the hub bearings with cone and straight taper bearings or are the ones you get from the auto parts store also the cup ones. Supposedly my Advance Auto can get me hub bearings for dirt cheap, but they have to order them and I was just wondering if anyone has done this.

[Tech Tim]

Thanks for posting that up Dave, I knew I had seen that posted before, it must have been you.

That answers a few things:

Axle Make: Chevrolet

Axle Rating: H052 is 5200, H072 is 7200 and it is the larger 1100 and 1500 that were rated 11,00 and 15,00lbs.

And the elusive 5.83 ratio. However has anyone ever seen one? The manual says only in the single rear wheel with the HD 3 speed trans.

[Tech Tim]

Originally Posted by AlxJ64

For response reasons I am going to refer to the 052s as having the non load bolt and the 072s as having the load thrust bolt.

Thats what I have been basing my input on, even though several folks say its just the size of the rear breaks. Which is possible if the 072 predates the 052 in manufacture date. But then again, maybe the 072 was originally for the DRW options? Strange.

That's a big 10-4. One would assume that anyone who has a load bolt 3rd in their small brake housing probably has had the 3rd swapped at one time and just don't know it. There is also the possibility that GM was assembling their axle and ran out of the 052 3rds so they slapped in a 072 3rd and called it good.

Originally Posted by AlxJ64

I have a junkyard / collector that I frequent about twice a year and he claims to have two of these center sections in the basement. I have seen them in person but did NOT verify the ratios. I will try to get a picture of the tooth count stamped on the gear next time.

That would be huuuge! They may be unobtainium, but if we could prove they exist, we'll know that they can be found. Again I'll say pics or it didn't happen and overall pics too to show what model 3rd they are in.

Plus another benefit is that IF a set could be found and obtained, then making a run of new R&Ps would be easier.

Originally Posted by AlxJ64

Now... I have a question.

The hub bearings that are in my axle are the original bearings I believe as the races are Cup shaped and the rollers are all very rounded shaped. They seem to be able to run at nearly any point on the race as its bowl shaped rather than a cone shape. Anyone have any input on this and has anyone replaced the hub bearings with cone and straight taper bearings or are the ones you get from the auto parts store also the cup ones. Supposedly my Advance Auto can get me hub bearings for dirt cheap, but they have to order them and I was just wondering if anyone has done this.

Not sure, but here is what my old 510 BCA book says:

65-66 All (Full-Floating) (GM axle) (leaf springs)
Inner brg #KD-11786-y
Outer brg # KB-11630Z
Seal # 455860

46-72 All (Full-Floating) (H050, H052, H072)
Inner brg #KD-11786-y
Outer brg # KB-11630Z
Seal # 2081

So they are showing all taking the same inner and outer bearings, but a different seal for the 65-66 model years, though they don't say what model they are referring to.

[472Scout]

Originally Posted by Tech Tim

The one on the right looks more like a ball bearing than a roller bearing?

[hmatiak]

I got my DRW ho72 tore down today. I was looking for numbers stamped on the r&p and didnt find anything. Trying to find the ratio so i can continue the rebuild. It has 32 teeth on the ring gear. Any were special to look for the ratio?

[Northern Drivetrain]

All of mine are stamped with the ratio on the nose of the pinion. If you look at the 3rd member from the ring gear side, look at the face that is showing through the pinion support bearing.

You probably have a 4.57 set (32:7)

Otherwise, count the teeth on the pinion, then divide the ring gear tooth count by the pinion tooth count to get the ratio.

[hmatiak]

I ended up finding it stamped on the inside of the ring gear. 7-32, so 4.57. Not bad for trading about 50 bucks worth of scrap for!

[hmatiak]

Originally Posted by Northern Drivetrain

All of mine are stamped with the ratio on the nose of the pinion. If you look at the 3rd member from the ring gear side, look at the face that is showing through the pinion support bearing.

You probably have a 4.57 set (32:7)

Otherwise, count the teeth on the pinion, then divide the ring gear tooth count by the pinion tooth count to get the ratio.

Thanks man. Like you said, it was stamped on the inside of the ring gear.

[hmatiak]

Upgrading from the 1/2 to 9/16 studs, what size bit? Anyone have a p/n for the replacement 9/16 studs?

[Filthy McChevy]

Originally Posted by AlxJ64

Now... I have a question.

The hub bearings that are in my axle are the original bearings I believe as the races are Cup shaped and the rollers are all very rounded shaped. They seem to be able to run at nearly any point on the race as its bowl shaped rather than a cone shape. Anyone have any input on this and has anyone replaced the hub bearings with cone and straight taper bearings or are the ones you get from the auto parts store also the cup ones. Supposedly my Advance Auto can get me hub bearings for dirt cheap, but they have to order them and I was just wondering if anyone has done this.

Not the best answer but I had those barrel shaped roller bearings in one end of one of mine and I swapped them out for straight bearings from another axle, because I did not like the way they could move around in the race. They looked fine and probably would work fine but I could not get past how odd they seemed and I had access to straight ones to put in anyway.

[Odin K30]

Originally Posted by hmatiak

Upgrading from the 1/2 to 9/16 studs, what size bit? Anyone have a p/n for the replacement 9/16 studs?

I have an extra set of 9/16s hubs if youre interested

[hmatiak]

Originally Posted by Odin K30

I have an extra set of 9/16s hubs if youre interested

I am. PM me your price. I am going to head to Napa shortly to see what they can come up with.

[AlxJ64]

Originally Posted by hmatiak

Upgrading from the 1/2 to 9/16 studs, what size bit? Anyone have a p/n for the replacement 9/16 studs?

I just used the Standard 9/16" 14 bolt stud for a SRW application. But I used a Hand reamer to get the diameter close. Under drilled and then cleaned it out to get as much bite from the knurls as I could on the studs.

[Odin K30]

Originally Posted by Tech Tim

Grrrreat tech thread....



First off, does anyone know for sure which year(s) they were introduced?







Are you sure on the load bolt and brake size being the only difference? There are some who say they've seen the H-052 with the load bolt.

I've been told that the 052 and the 072 have a difference Pinion Mtg Depth. Anyone have any insight?

Has anyone taken a ring and pinion from a 052 and put it into a 072? or vice-versa?

They were introduced in 1947.

I have swapped the ring and pinions from 052 to 072 like previously posted without any noticeable difference.

[Tech Tim]

Originally Posted by Odin K30

They were introduced in 1947.

They? You mean both the H052 and the H072?

The earliest reference I can find for the H072 is 1946.

The earliest reference I can find for the H052 is 1956.