Currie HP44 Front Axle - Outer seal?

[NorCalBronco]

I received my front axle from Currie recently. It came assembled out to the inner knuckles. What seal/part/whatever supports the axle at the end of the tube/inner knuckle area and keeps stuff out of the tube? The way it comes there is nothing there and there is just a gap around the axles where they enter the tube. I've found some random Dana44 diagrams that seem to mention an outer seal but I'm not seeing that on any of the vendors sites? I haven't tore into my original 44 on my Bronco yet but peaking in there it seems like something is installed underneath all the grease and mud

 

[DirtDonk]

Nope. No seal usually.
There are aftermarket seals that fit Jeep front axles, and I don’t know about the specific Currie unit. But there is no outer seal from the factory on the model 44’s in Broncos.
Only some of the 30s.

 

[NorCalBronco]

Nope. No seal usually.
There are aftermarket seals that fit Jeep front axles, and I don’t know about the specific Currie unit. But there is no outer seal from the factory on the model 44’s in Broncos.
Only some of the 30s.

Interesting thank you. So no seal there.. not even some sort of plate/shield that keeps small rocks and stuff from being wedged between the axle and the tube or anything?

 

[Yeller]

No, nothing. Works fine. Been that way since it’s inception 70 years ago….

 

[NorCalBronco]

No, nothing. Works fine. Been that way since it’s inception 70 years ago….

Awesome thank you. This makes me happy since it means I don’t have to order and wait for anymore parts to start assembling everything

 

[DirtDonk]

We did spend many years however, looking for a solution, that was reasonable, didn’t wear out too quickly, and would still keep debris out of the tube.
To be sure, debris in the tube isn’t actually a huge issue. Water either.
It does look ugly in there sometimes, but it rarely causes a problem.
And one of the downsides to the seal, if you do water crossings and such, water does get in and then can’t get out.
So rust and water in the oil become an even bigger issue than they would’ve been with an open tube. They probably discovered that at the factory with the 30s in the early years, and eliminated the seal.
Seal can’t offer much support in the middle of the long run like that. The support of the inner bearing and the outer spindle bearing is sufficient for a long life.

 

[jamesroney]

No, nothing. Works fine. Been that way since it’s inception 70 years ago….

@Yeller is right.
There is nothing there. It works as poorly as you would expect. It has been working poorly since it became prevalent in the mid 60's, which was less than 60 years ago. Prior to that, the closed knuckle was the preferred embodiment.

There is no end of crud, mud, crap, and rust that accumulates in the axle tubes. They work marginally well, until you service the inner shaft and shove that crud into the seal.

It is for this reason that the aftermarket has invented the outer tube seal. Factory inner axles have a flange forged into the yoke end to act as a deterrent for the crud. Aftermarket axle shafts often do not.

There are some really nice o-ring sealed billet aluminum tube seals on the market. They will not help to keep a leaky inner axle seal from weeping. But they are pretty good at keeping mud and bugs out. (They won't fix a bent axle tube on a Rubicon Dana 44.) But as @DirtDonk correctly points out....they trap water and can actually make things MUCH worse.

I do admit that I have removed 50 year old D44 housing tubes and found them to be in amazingly perfect condition. But I have also serviced 10 year old D44
shafts that were full of crud.

 

[jamesroney]

I received my front axle from Currie recently. It came assembled out to the inner knuckles. What seal/part/whatever supports the axle at the end of the tube/inner knuckle area and keeps stuff out of the tube? The way it comes there is nothing there and there is just a gap around the axles where they enter the tube. I've found some random Dana44 diagrams that seem to mention an outer seal but I'm not seeing that on any of the vendors sites? I haven't tore into my original 44 on my Bronco yet but peaking in there it seems like something is installed underneath all the grease and mud

You can see the little flange molded into the inner shaft in this pic. It looks like a pretty decent housing.

Can you confirm that the end forging is welded on the ID at the tube end? It's hard to tell from the pic. Also, curious to know how much caster that Currie builds into the housing. Did you specify the caster, or did they sell you a catalog housing? I just wonder how much lift they are recommending for this housing, and whether they let you pick?

 

[NorCalBronco]

You can see the little flange molded into the inner shaft in this pic. It looks like a pretty decent housing.

Can you confirm that the end forging is welded on the ID at the tube end? It's hard to tell from the pic. Also, curious to know how much caster that Currie builds into the housing. Did you specify the caster, or did they sell you a catalog housing? I just wonder how much lift they are recommending for this housing, and whether they let you pick?

Here is a couple of pics. There wasn't an option for specifying caster that I saw. I have some Toms extended arms with some caster adjustment built in that I will be using. The listing on their website says "Designed for stock height and lifted vehicles"

 

[jamesroney]

Thanks for the detail!

I went to the garage and dig up some old inner shafts. Here’s a picture of the 4 different types of factory “nothing” that @Yeller mentioned.

You can see an old D30 shaft with the two seal surfaces, a TJ D30 shaft with the plastic collar, a D44 shaft with a slinger, and a d44 shaft with the forged flange.

So in every case, the OEM did “something” but the net result is basically the same “nothing.”

Hope that makes sense.

What’s the plan for your old housing?

 

[NorCalBronco]

Thanks for the detail!

I went to the garage and dig up some old inner shafts. Here’s a picture of the 4 different types of factory “nothing” that @Yeller mentioned.

You can see an old D30 shaft with the two seal surfaces, a TJ D30 shaft with the plastic collar, a D44 shaft with a slinger, and a d44 shaft with the forged flange.

So in every case, the OEM did “something” but the net result is basically the same “nothing.”

Hope that makes sense.

What’s the plan for your old housing?

Thanks for the examples!
As for the old housing, I hope to sell it to recover a small portion of the money that the new one cost!

 

[markw]

That cost is significant. It’s sure a nice piece of work though. Beat the heck out of it in Baja including breaking off a concrete power pole at 80 mph. Pulled through just fine though the rest of the Bronco didn’t.


Sent from my iPhone using Tapatalk

 

[toddz69]

I just went back and re-read the description of that housing - I didn't realize it was 1" wider than stock. I thought Currie used to have a low-pinion version too but they don't - Tom's does though with similar construction which makes me wonder if Tom's got an exclusive for the low-pinion version.

And fun fact from the history guy - the Bronco's D30 was the first open-knuckle axle used on a domestic 4x4. Ford did extensive testing with it at the AZ Proving Grounds prior to the Bronco's introduction to make sure that its lack of seals would work ok. Obviously - 58 years later, they were right.

Todd Z.

 

[jamesroney]

I just went back and re-read the description of that housing - I didn't realize it was 1" wider than stock. I thought Currie used to have a low-pinion version too but they don't - Tom's does though with similar construction which makes me wonder if Tom's got an exclusive for the low-pinion version.

And fun fact from the history guy - the Bronco's D30 was the first open-knuckle axle used on a domestic 4x4. Ford did extensive testing with it at the AZ Proving Grounds prior to the Bronco's introduction to make sure that its lack of seals would work ok. Obviously - 58 years later, they were right.

Todd Z.

I don't think it actually is wider. I hope that we can ask @NorCalBronco to measure the distance between ball joints on the bare housing, and compare that to an original D44. (image coming soon...)

I think that Currie is using the same incorrect reference dimension from the Early Bronco literature. Their website says that their housing is 60 inches WMS. That is the same as Early Bronco disc brake 44.

The axle that Currie is peddling is basically a Jeep JK Rubicon high pinion center with the link mount deleted. With the thick wall 3 inch tubes, It vastly superior to anything ever put into any Bronco. (including 6G) I really like it.

Be aware that there were three kinds of Dana 44 tubes that came in a Jeep JK. Bent ones, soon to be bent ones, and never driven ones.

@NorCalBronco you will want to get a comprehensive BOM for your axle from Currie. They are REALLY bad at "remembering" what they built. In about 10 years, every component on your axle will be obsolete, and no one at Currie will tell you (or know...) what you've got. But if you can get a master list, you will really appreciate it if you ever have to service it. I'm pretty sure that they used 2007-2018 JK Rubicon ring and pinion. But I don't know which carrier, which spline count, and which bearings. Also want to know the dimensions of the inner stubs. A drawing would be acceptable, but knowing the application would be even better. I often get 10-20 year old custom axles in for repair, and have no clue what was built. Dynatrac and Currie are the worst, but TeraFlex is trying hard to catch up. Solid Axle is remarkably "solid." I've given up on the 9 inch stuff, and I'll only order parts AFTER I confirm.

The only thing worse than having a custom axle manufacturer unable to answer a question is to be unwilling to answer. You can imagine the conversation...
ME: "Hello, I am working on a Bronco Axle that I didn't buy, that I have no receipt for, that has no serial number, but it has a really pretty Logo welded on it. Do you have the inner axle seal part number?"
THEM: "No. Are you going to spend $4900 today? Go away."