Currie axle

[Jakedog]

I almost ordered a currie 9" today. I was going to go the full crate axle route so I could just remove the old one and install a brand new assembly. I called and got a price quote a couple of months ago. The quote was for a 35 spline 9" with 4.30 gear, Detroit true trac, drain plug, explorer disk brakes, and powder coat. It was around $4400. I was going to pick it up and save on freight since it's only around a 2 hour drive.
I know I can probably piece it together cheaper, but I would still need to pay for assembly. I have never built an axle assembly, and I wouldn't want to take the chance of destroying new parts due to bad assembly.

Have any of you guys ever bought a custom crate axle for your bronco? Were you happy with the results?

 

[spap]

Why don’t you just take your current axle to Currie and have them build it. It will save some not tons. Currie is a great product . With everything that is ordered that isn’t a bad price.

Curious why did you pick a 4.30 Gear ratio

 

[Jakedog]

Why don’t you just take your current axle to Currie and have them build it. It will save some not tons. Currie is a great product . With everything that is ordered that isn’t a bad price.

Curious why did you pick a 4.30 Gear ratio

I chose the 4.30 based on a lot of reading on CB and other sites. I'm running 35" tires and an np435, and most of the advice suggested either 4.11 or 4.56. A couple of people suggest 4.30. I saw that Currie offered a 4.30 option so I figured middle of the road.

Also, I have a small bearing axle and I plan on switching to a big bearing either way.
I've used the gear calculators as well. I'm open to suggestions from those who have or do have the same set up.

 

[DirtDonk]

Did you verify you could get the 4.30 (or equivalent like maybe a 4.27?) for the Dana front axle in your rig? You have a 30 or 44?

Paul

 

[DirtDonk]

Also, nothing against a crate axle, but if you want to piece meal it together in order to save money now in the short term, rather than spending it all at once in a big chunk, you could order the center section already built, put it in your old housing with new axles and be into it for much less.
Initially anyway.

You'd still end up buying a new housing with the big ends, then two new axle shafts (again) to replace the 31 spline axles you got with the custom small bearings. So you're actually buying new shafts twice.
But you also have two almost new shafts to sell, along with the small bearing housing, to recoup some of your money for the new stuff.

It can work out in the end, even though you go through a couple of iterations.
And you still end up with a custom beefed up housing. That is unless in the meantime you find a nice inexpensive used big-bearing housing instead.
But with all that work I'd opt for the new beef housing unless you have no need for the strength.
That part depends on what you want to do with the Bronco, or how you want it to look underneath.

Just some possible scenarios. If you're of the "let's just get it over with in one fell swoop" mindset, then the crate axle will work.
I see we still haven't made a "crate axle" category even though we have, or can get all the parts. Maybe that's because we don't stock all the different iterations of the 3rd members and don't always build them in-house. Lots of options there!
But at least it's still something that can be done.

Hard to go wrong either way.

Paul

 

[fordguy]

I ordered a housing and found a used 4.11 chunk and used 28 spline axles. I already have exp disc. Also ordered rotors with correct bolt pattern. If I like it, then I will decide on diff choice. If I don’t like 4.11s then I will change ratio. Changing diff on a 9 inch is super easy.

 

[bax]

Kiddsplay has a currie high pinion center section in parts for sale. Get that and find a 77 rear housing and you will be in good shape. Half the money.

 

[Broncobowsher]

I had a local diff shop build a custom axle for a project at work. Fab 9 housing, strange aluminum third member, aluminum datyona pinion support, True trac, solid spacer. All the good stuff for under $5k. I just had to weld the mounts on where I wanted them.

Just saying there are other options for a complete 'crate' axle besides Currie. Don't be afraid to shop around

 

[SteveL]

Kiddsplay has a currie high pinion center section in parts for sale. Get that and find a 77 rear housing and you will be in good shape. Half the money.

If I remember right it's a 35 spline. That turned me away.

 

[SteveL]

Outside of setting up the gears the rest bolts together pretty simple. Order a 3rd member set up and put the rest together at home.

 

[Jakedog]

Did you verify you could get the 4.30 (or equivalent like maybe a 4.27?) for the Dana front axle in your rig? You have a 30 or 44?

Paul

Yukon makes a 4.27 for the front.

 

[Nothing Special]

Did you verify you could get the 4.30 (or equivalent like maybe a 4.27?) for the Dana front axle in your rig? You have a 30 or 44?

Paul

I had a '75 Jeep CJ5. It came from the factory with 4.27s in the front Dana 30 and the rear Dana 44. So I'm thinking either will be available still.

 

[DirtDonk]

Yep, a regular gear for Danas back in the day, so probably still available. Just haven't looked for a set in a very long time so didn't know if they were readily available from the usual suspects.

Paul

 

[Jakedog]

Yep, a regular gear for Danas back in the day, so probably still available. Just haven't looked for a set in a very long time so didn't know if they were readily available from the usual suspects.

Paul

Would there be that much of a difference in feel between a 4.11 and a 4.30?
It seems like a 4.56 would be to low for highway driving. Maybe I'm overthinking this whole process, but I only want to do this once.

 

[bax]

Well with a 315 tall tire / about a 33'' with a final drive of 1/1 the 4.11 would work pretty good. The 4.30 still fine with limited high speed driving. the 456 might be a little steep for some. Find a gear calculator and plug in the numbers

 

[Jamie Chriss]

I have the exact rear end from Currie! I ended up having them rebuild my entire Dana 44 to match. I went all new on the rear, the previous owner I was an idiot and Frankensteined it together with a bent right side.

 

[DirtDonk]

Which gear ratio did you go with Jamie?

Jakedog, there's an approx. 120rpm change between a 4.11 and 4.30 when using 34" as an actual rolling diameter tire size at 65mph.
It goes up another 130, or thereabouts with the 4.56.

We're not talking a lot of rpm change, but you can still feel it in the seat of your pants with each step.

Paul

 

[Jakedog]

Thanks for all the advice. I think I have a pretty good idea of what I'm going to go with as far as axles and housing. I just need to decide what gear ratio to use.

I don't plan on a lot of highway travel but I need my rig to be as versatile as possible. Good on road and better off road.
One of my goals is to drive to the Wild Horses roundup. Its about a 250 mile drive for me. So I'm guessing 3.5 to 4 hrs on the road. That's why I was debating between a 4.11 or a 4.30. The 4.56 seems a little too low for that long of a trip.

The calculator I tried to use wasn't cooperating earlier. I'll try a different one and see what I come up with.

Again, thanks for the advice, guys. I have a tendency to over think and second guess myself when it comes to this stuff.

 

[bax]

Jakedog, a few numbers for you. I used a 33'' tire with a 1 to 1 final drive out of the trans. set my highway rpm at 3000
4.11 at 3000 = 71 MPH
4.30 at 3000 = 68
4.56 at 3000 = 64
4.88 at 3000 = 60
5.13 at 3000 = 57
with the fact that you are wanting more off road than on road. The fact that you are 1 to 1 / no overdrive ( the future could have an OD ) the fact that 3000 rpm is for 4 hours is not bad. The possibility you may get taller tires one day. The fact that doing 70 MPH in a bronco is not the most relaxing Cruze out there. The fact that back roads at 55 still get you where you're going. With this said my easy choice is 4.88. Don't do the 4.11 or the 4.30 . If you ever upgrade to overdrive or bigger tires the rpm's go lower and with the 4.88 or even the 4.56 your still in a good rpm range.

 

[KyddsPly]

I made the mistake of going to high on my gears during the build. I was running 4:10’s, and then decided this year to regear to something a little bit more, fun. The best advice I can give you is what speed will you be averaging. And make a decision from there. Going from 410s to 456, did give me a little bit more RPM, but it gave me a whole lot more go factor. Wishing I would’ve done this to begin with.


Sent from my iPhone using Tapatalk Pro