Even if they had to machine a shim to go between the chuck and housing face to get the dept correct on one of their existing housings, would that be so bad?
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Eaton HO72 Tech Thread
- Thread starter 06h3
- Start date
gtxracer2
180 header nutcase
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Oh that's great! I can check in with them. I'm still considering a cut/slug/weld for my front axle with a unit bearing option for the rear axle. I have SRW hubs which push the WMS to 65" and then use 2" spacers in the mean time for 69" total WMS. I don't like spacers, especially with a U4 style car and driving style. I have a spare H072 third that's assembled with alignment pucks that I can send to a vendor to make things easy.
I'll keep you in the loop. Maybe they'll give us a great deal if we order a few housings at once.
gtxracer2
180 header nutcase
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Extra leak source unless you weld the shim to the housing. That's not awful.
GLTHFJ60
Stupid is as stupid does
May be an ignorant question, but if the 14b innards work in this housing (more or less) what's the advantage of using this over a 14b? Lighter weight housing?
Lighter weight, removable 3rd for service (if you need it) more ground clearance, especially when I built mine. It wasn’t popular to do the crazy shave that everyone does on 14b’s now, where you shave the ring gear, cut out the bottom part of the housing and weld in plate.
They are cool! Lol
I wonder what the true difference is on strength. It’s got a load bolt and 3rd bearing support where the 14b is just 3rd bearing support
AlxJ64
Rust is Paint
The OEM Spherical bearings in these vs the flat face tapers in the 14b are a huge component of the original strength of these as well. Allowing flexure without reducing bearing surface contact is a huge advantage.
GLTHFJ60
Stupid is as stupid does
The rollers of a modern taper roller bearing aren't flat, they're tapered slightly, right? Is that not the same thing?
AlxJ64
Rust is Paint
They're tapered to run the speed of ramp that the race is on due to the difference in diameter of the cup from "top" to "bottom"; however that is not the same thing I am referencing. The OE bearings in these units are machined in an orbital, so no matter how the bearing aligns in the cup, it has uniform contact patch. If a modern taper bearing is loaded in non-perpendicular direction (such as a cup not being seated squarely and the shaft is slightly out of 90 degrees, which occurs during shaft twisting) and supporting element flexure occurs (case distortion), the bearing rollers don't distribute load the same and can be more easily damaged. I'll dig out some parts and take photos for comparison. Think of how a normal taper bearing "finds its home" when you drop the cone into the race. Well, the OE Eaton stuff sits in a "bowl" and you can run that thing crooked AF and it doesn't care and has the same contact surface the entire time.
DMANbluesfreak
Trailers are for Boats
^This is exactly why bearing pre-load is so important. It helps eliminate or reduce the amount of non-perpendicular load.
Alright, I have now broken 3 short side (driver) shafts....I don’t think my housing is bent on that side to cause that, maybe it is but I don’t jump it so I don’t think it is.... maybe I verify that it isn’t? If so, how? Maybe since it’s the short side there’s less twist from the shaft?
Anyways, I’m almost committed to 17 spline for one reason. My locker. I have a 17 spline Detroit locker and a spare. Normally, I’d say just buy a 30 spline Detroit or grizzly and move on with RCV 300M 14 bolt shafts but I have not seen a single instance in person that doesn’t wipe out a Detroit or grizzly when a shaft breaks. I’ve seen probably 5-6 axle shafts break on different rigs and different axles and the shaft takes out the locker everytime. Doesn’t matter if it’s Detroit or grizzly. My 17 spline Detroit has survived 3 broken shafts and still works. Maybe it’s that 1956 metal where we actually cared about quality back then.
I could try 14 bolt shafts but I’m not convinced they are stronger. I have spiral twisted an eaton shaft, I assume they have more twist then 14 bolt shafts.
I have twisted the splines ever so slightly on one shaft. So that does concern me if I get custom 300M shafts made for 17 spline, 30 spline would have a smaller chance of twisted splines?
So, I gotta decide.
-14 bolt locker with 300M shafts.
-14 bolt locker with stock shafts (see if it breaks and if it does I need a new locker since it will break too)
-custom 300M shafts from RCV or summer brother racing.
-Custom Hy-tuf axles (supposedly 300M) from Dutchman, they are 2.5 miles from my house which is nice.
-keep throwing stock shafts at it.
-“comp cutting” axles? Supposedly old metal responds well to it, Carl Jantz does it.
-37 or 40 spline, (I don’t think I’m at that point yet and shouldn’t be considered but figured I’d mention it)
Here are pics for my shaft carnage.
Break 1- 2018, east coast wheeling, 40in Coopers, slightly twisted splines, spiral crack causing shaft to bend. Wild break, technically it never broke. It still worked, I found this carnage after a highway jaunt and the hub was piping hot from the binding.
Break 2: 2021, Moab, 43in tires, pure stupidity. Giant hole, wasn’t paying attention, bound up. Clean break 2in off the flange.
Break 3: 2022, 43s, local Idaho trail, all the weight on the rear, steep climb, fell into an undercut and broke. Splintered and shattered at about 60-70% of shaft length away from the flange
Anyways, I’m almost committed to 17 spline for one reason. My locker. I have a 17 spline Detroit locker and a spare. Normally, I’d say just buy a 30 spline Detroit or grizzly and move on with RCV 300M 14 bolt shafts but I have not seen a single instance in person that doesn’t wipe out a Detroit or grizzly when a shaft breaks. I’ve seen probably 5-6 axle shafts break on different rigs and different axles and the shaft takes out the locker everytime. Doesn’t matter if it’s Detroit or grizzly. My 17 spline Detroit has survived 3 broken shafts and still works. Maybe it’s that 1956 metal where we actually cared about quality back then.
I could try 14 bolt shafts but I’m not convinced they are stronger. I have spiral twisted an eaton shaft, I assume they have more twist then 14 bolt shafts.
I have twisted the splines ever so slightly on one shaft. So that does concern me if I get custom 300M shafts made for 17 spline, 30 spline would have a smaller chance of twisted splines?
So, I gotta decide.
-14 bolt locker with 300M shafts.
-14 bolt locker with stock shafts (see if it breaks and if it does I need a new locker since it will break too)
-custom 300M shafts from RCV or summer brother racing.
-Custom Hy-tuf axles (supposedly 300M) from Dutchman, they are 2.5 miles from my house which is nice.
-keep throwing stock shafts at it.
-“comp cutting” axles? Supposedly old metal responds well to it, Carl Jantz does it.
-37 or 40 spline, (I don’t think I’m at that point yet and shouldn’t be considered but figured I’d mention it)
Here are pics for my shaft carnage.
Break 1- 2018, east coast wheeling, 40in Coopers, slightly twisted splines, spiral crack causing shaft to bend. Wild break, technically it never broke. It still worked, I found this carnage after a highway jaunt and the hub was piping hot from the binding.
Break 2: 2021, Moab, 43in tires, pure stupidity. Giant hole, wasn’t paying attention, bound up. Clean break 2in off the flange.
Break 3: 2022, 43s, local Idaho trail, all the weight on the rear, steep climb, fell into an undercut and broke. Splintered and shattered at about 60-70% of shaft length away from the flange
TTMotorsports
Red Skull Member
I know of one of these at a house where he's selling everything to clean it up to move. It's in Phelan CA so let me know if anyone is interested
What ratio 3rd?
TTMotorsports
Red Skull Member
No Idea on the ratio. I simply saw it sitting on ground next to the forklift propane tank I was buying and put it in my memory. It was last week and the guy selling the stuff doesn't know anything about cars at all. He had a 14 bolt rear axle that the tubes were cut on and he was like hey can you check out this transfer case and tell me what it is. Well i told him it was a scrap 14 bolt center with cut tubes. So if someone were to buy this they could grab that as well for free. If it's got an open diff you can usually sell those for a bit of $ since they are required for lockers.
AlxJ64
Rust is Paint
I am building a crate right now to send a bunch of my Eaton parts to someone who is putting a 40 spline ARB in one and running double float RCVs and 14 bolt hubs. I can get you in touch with him and maybe ya'll can order parts in a two fer deal or something.
TTMotorsports
Red Skull Member
This is the guy who has the rear axle sitting in the dirt And he has a ton of other things as well for anyone who collects stuff.
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That would be awesome! I wonder who’s doing the machine work for the ARB
TrailTamer
🤣🖕🏻
I vote this.
Get the Yukon grizzly locker instead of Detroit. Grizzly shouldn’t break, but if it does break, Yukon will give you new one, plus $$ if it destroy something else in your diff.
Run the stock 14b shafts. Chances are they’re made better than ancient ones used in ho72s, alloys and heat treatment.
Worst case, you’re not out much if need to step up to 4340 or 300m
TrailTamer
🤣🖕🏻
Seem like should be easy to find out. Remove the third member and take the cover off, measure face to face distance, divide by 2…..?
I’m 98% confident the grizzly will break. Every shaft break I have seen personally with a grizzly resulted in a broken grizzly.
I will buy a grizzly 14 bolt for testing purposes. I’m intrigued to see if it’s better!
TTMotorsports
Red Skull Member
I've had a Grizzly locked in the back of my brothers 01 silverado Prerunner for 6 years now and no issues at all running 37's and high speeds. No rock crawling torque but still shock loads through whoops and such.
gtxracer2
180 header nutcase
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That does appear to be a great point :D measure and let me know!
I have a 17 spline Detroit in the rear of my TJ. I plan to remove it for a 14B spool for better street manners. I’d love an ARB but don’t want to spend $3k setting it up. If it was more like $1500 I’d be interested. I even bought a 30 spline ARB and took measurements to reverse engineer the case into Solidworks and make changes for the Eaton H072 gearset. It’s not that hard to do but I don’t want to or have the means to do the machining anymore.
My 17 spline Detroit unlocks so hard I can feel the Jeep tug to the left. If the 4l80e shifts at the same time, I usually shit my pants.
gtxracer2
180 header nutcase
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Yup that’s me. To use a Detroit or Grizzly, you need to machine the inside mounting face of the carrier ~0.060” from each side. If you don’t, the locker won’t disengage. I run a 30 spline 14B Detroit locker in my front Eaton H072 and it has washers between the locker case halves because I didn’t have access to a lathe at the time. This works in a pinch but machining the halves is much better.
When I say the rear end unlocks violently, I really mean it. It clicks and bangs HARD sometimes, especially when the 4l80 is also shifting. The 4l80 has a transgo shift kit on softest setting for reference.
When I say the rear end unlocks violently, I really mean it. It clicks and bangs HARD sometimes, especially when the 4l80 is also shifting. The 4l80 has a transgo shift kit on softest setting for reference.
Great tech on the machining tolerances. Thank you! If I remember correctly that isn’t on all carriers right? Just older HO72s? The older ones need the ID machined out for 14 bolt shafts too...I have multiple carriers, my plan is to put my grizzly in a carrier I have laying around, bench test it, if it works, great, if not I’ll get it machined down.
I’m actually excited about this test. For years on the old forum and old HO72 thread which was like 70 pages there was talk about HO72 shafts are stronger, some said, no, 14 bolt shafts are stronger....but no real data on it other then “he said, she said” opinions. This is an apples to apples test. Same axle, same rig, same tire size and power, I broke 3 shafts. Now let’s see what the grizzly and 14 bolt shafts do.
I’m torn, one argument is technologic advancements. The other argument is the quality is better back in the day.
I’m on the quality 50 years ago = better. Detroit’s and grizzlys break when shafts break. I have seen it time and time again, regardless of axle or locker type. My old 17 spline Detroit won’t break. I would like to think the shafts are in the same boat.
Now I’ll put my money where my mouth is and do the test.
Lastly, that sucks on the Detroit. Mine works perfectly. It unlocks nicely, locks nicely, I honestly can’t think of a violent interaction with my Detroit once in 6 years. The only think I can think of is every once in a while when you get on the gas you hear it engage, I know the sound, I know it’s not a problem but when I’m on the trail or have a passenger on road I immediately get asked, “what did you break?” It sounds terrible but you don’t feel it. It’s weird
DMANbluesfreak
Trailers are for Boats
I'm really interested to see the results of your test, honestly. I think it's not so black and white when comparing HO72 axle shafts and 14b axle shafts.
I'm definitely more in the 'technological advancement' side of the argument, but both can be true and newer shafts still be stronger. You can have perfect quality on metal that's poorly heat treated and they'll be shit. Similarly, you can have poor quality on ideal alloys/heat treatment and they'll be shit.
Assuming the lockers are the same (they're not), I'd argue that a newer shaft being stronger (hypothetical) but still breaking would be more likely to destroy a locker because the shock load would be higher. That might be why you see more 14b Grizzlys and Detroits breaking.
This is all hypothetical and not based on any facts, lol.
Regarding the locking/unlocking of my Grizzly - I get the same thing. People think something broke when it unlocks under moderate torque, but it never really upsets the vehicle much. I think a lot of that has to do with wheelbase. Gtxracer2 said he's running it in a TJ. You and I have over ~125" wheelbases and probably 2klbs more, so one rear drive wheel losing torque wouldn't upset the direction of the rig as much.
I'm definitely more in the 'technological advancement' side of the argument, but both can be true and newer shafts still be stronger. You can have perfect quality on metal that's poorly heat treated and they'll be shit. Similarly, you can have poor quality on ideal alloys/heat treatment and they'll be shit.
Assuming the lockers are the same (they're not), I'd argue that a newer shaft being stronger (hypothetical) but still breaking would be more likely to destroy a locker because the shock load would be higher. That might be why you see more 14b Grizzlys and Detroits breaking.
This is all hypothetical and not based on any facts, lol.
Regarding the locking/unlocking of my Grizzly - I get the same thing. People think something broke when it unlocks under moderate torque, but it never really upsets the vehicle much. I think a lot of that has to do with wheelbase. Gtxracer2 said he's running it in a TJ. You and I have over ~125" wheelbases and probably 2klbs more, so one rear drive wheel losing torque wouldn't upset the direction of the rig as much.
AlxJ64
Rust is Paint
For the 14B Detroit thats in the front of my Carryall, I machined the inside face of the Detroit side gears rather the inside face of the carrier. This way it didn't matter if the machine work was perfectly square from side to side but rather just created enough end clearance for the drive gear to rise and cam over during a coasting ratchet. Just needs a little end clearance.
It seems that the carriers that need to be bored open are anything earlier than the '70 stuff. I've helped put 14B shafts in two different '70 and '71 stamped thirds and they had just barely enough room to fit the 14B shaft through.
It seems that the carriers that need to be bored open are anything earlier than the '70 stuff. I've helped put 14B shafts in two different '70 and '71 stamped thirds and they had just barely enough room to fit the 14B shaft through.
Im 115” but I agree with you, my buddy and his dad have TJs. He had a Detroit (before going spool) and his dad has a grizzly. His grizzly behaved normal except for 1 occasion. He was making a right hand turn and it locked up weird, he said it damn near lifted the front tire, if he didn’t let the clutch out he would have flopped the thing on the road. He basically shit his pants
longer wheelbase and weight help alleviate those issues. How much material did you take off?For the 14B Detroit thats in the front of my Carryall, I machined the inside face of the Detroit side gears rather the inside face of the carrier. This way it didn't matter if the machine work was perfectly square from side to side but rather just created enough end clearance for the drive gear to rise and cam over during a coasting ratchet. Just needs a little end clearance.
It seems that the carriers that need to be bored open are anything earlier than the '70 stuff. I've helped put 14B shafts in two different '70 and '71 stamped thirds and they had just barely enough room to fit the 14B shaft through.
AlxJ64
Rust is Paint
The number 0.130" seems to ring a bell. I'll have to dig in my notes to see exactly what it was.Im 115” but I agree with you, my buddy and his dad have TJs. He had a Detroit (before going spool) and his dad has a grizzly. His grizzly behaved normal except for 1 occasion. He was making a right hand turn and it locked up weird, he said it damn near lifted the front tire, if he didn’t let the clutch out he would have flopped the thing on the road. He basically shit his pants
How much material did you take off?
I also have messed with the 14B TorqMasters locker that re-uses the side gears and that doesn't fit in the carrier the way one would hope because of the entire hemisphere of the carrier case being slightly different. The tooth profile of a 14B side gear to an Eaton Side gear is also different.
I tried to find the pictures i have of the two side gears together for comparison but can't seem to locate it.
TrailTamer
🤣🖕🏻
I’m just a spectator here, as I don’t have any ho72 hand-on experience.
How similar are 14b and ho72 carriers? Deck height, snout bearing diameters, ring gear pilot diameter, etc.? Close enough to make the 14b carrier to work, to open up on locker options, including arb?
How similar are 14b and ho72 carriers? Deck height, snout bearing diameters, ring gear pilot diameter, etc.? Close enough to make the 14b carrier to work, to open up on locker options, including arb?
Guys have modified ARBs to work but it isn’t a drop in or deal. I’ll have to find pics from one guy that did it