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Currie FJ Ford 9 Axle

As we know the FJ aftermarket is oversaturated in the suspension department, but almost no products are available for the driveline. We are breaking spindles, links and a number of us are breaking gears.

For those new to rear ends (as I am), the stock 8.4" Toyota ring and pinion is just too small for the way we are using it. There have been many broken ring and pinions - I read about one Moab run where 10% of the FJs broke theirs. We like to load up with a lot of cargo and big tires, and when wheels hop on the rocks that's it.

Currie will release a Ford 9-inch axle for the FJ, a must-have item for many of us. This gives us two state of the art choices in rear axles, including the new All-Pro/Currie Dana that just came out. This is about my day there and what I learned about this new product for the FJ.

To oversimplify, there are two primary aftermarket gear sets for factory offroad vehicles. The Dana series for crawlers, and the Ford 9 for racers. Dana pinions are 2 inches above the rear axle, and the Ford 9 is two inches below. So who wants a Ford 9? It's stronger and takes the sudden shock loads of high-speed runs better. But that clearance creates an issue over the rocks.

Dave Castillo called me to come in and let him take some measurements. He is the product designer, and just finished up working with Jon at All-Pro to develop the All-Pro/Currie Dana Rock Jock axles for the FJ. Mine will be the prototype Ford 9, made on the same fixture the All-Pro Dana is made on.




Currie is THE name in rearends, dating back to the fifties. Here is their huge building in Anaheim.




Row after row of the new All-Pro Currie Dana axles ready for shipment.




Every rear-end related item you can think of, manufactured in-house for just about every performance car and truck out there.




Dana displays for Jeep. The Rock Jock rear on the right looks very similar to the All-Pro axle.




A small portion of their industrial-quality manufacturing shop.




Waiting for paint after assembly. A Ford 9 is second from the front.




A final JK rear axle. Never thought I would admire a rear axle for build quality, finish and aesthetics, but they really look great.




And there's the patient! The first-ever Ford 9" for the FJ in Dave Castillo's fixture.




Currie Track-9 is the NASCAR standard almost without exception. This is the heaviest housing of the Track-9 series, from 26 to 18 lbs.

Housings and covers are formed from high tensile (High Form 50/Spec A715) steel. This material is 39% stronger than conventional 1010 low carbon steel. So it's halfway between mild steel and Chromoly in strength.




Currie was clever enough to improve on the FJ's delicate shock mounts. They rotated the lower shock pin 90 degrees so that it gains almost an inch in ground clearance without reducing travel. You will notice that the bracket here is 90 degrees to the stock one.




This fixture will be moved off the test bench and into production when the final measurements are taken off my stock axle. Right now all the brackets are tacked into place and will probably be adjusted slightly.




Custom CNC large-bearing housing ends just for the FJ.




Now it was time to make sure this axle fits the FJ properly. So up on the lift and get out the measuring tape.







My stock housing, mere weeks away from its next explosion, was still too hot to touch. This is because my tweaked ring and pinion are trying to destroy each other and creating a lot of friction in the process.

They said the oil leak is because the front cover has been shrinking and expanding from the heat, and that has wrecked the seals over time.




On the left is a stock Tacoma axle like we have, and on the right is the blank for their FJ axle. It looked about .25" larger but I did not have calipers. They will cut it to length, drill the lug pattern in the end, and cut the 35 splines on the skinny end.

The one bit of bad news is that they want me to get a driveshaft too. Apparently the Ford yoke doesn't match up with the Toyota one. However, I bet they can come up with a fix for this once the axle is finalized into a real product.

Next week they will call me in to install it. It'll be nice to not worry about blowing up the rear end, and it will be a lot quieter on the freeway without the whining of gears locked in mortal combat with each other.
 

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all right Todd. :clap:

this will be a nice one for sure, I am sure it will look stunning when it is all done and installed.

Did you tell them yours needs to be wider then stock?
 

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Did you tell them yours needs to be wider then stock?
Hah! Yeah I remembered that yesterday suddenly and almost fainted. Fortunately I told them when I ordered it a few weeks ago. Dude when you hit 40 you'll do the same
 

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Mine will be ... gulp ... $4100 with tax. The production one will be cheaper. For you guys, they said to look at All-Pro's site for the price breakdown of theirs. The Ford 9 version will be very slightly more.

Fortunately the sales guy at the Meet and Greet looked up my lease and said my buyout will be about $12K. About the only good financial news one can have for FJs...
 

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Todd, thanks for the pictures and the side by side comparisons. It was really helpful in visualizing them. What a rear end nightmare you've had! Hopefully it's coming to an end (and it looks like it) and you can enjoy it as it should be enjoyed.
 

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Hah! Yeah I remembered that yesterday suddenly and almost fainted. Fortunately I told them when I ordered it a few weeks ago. Dude when you hit 40 you'll do the same
:lol: as long as you told them some time. :D I will never hit 40 I will stay young forever. :)

Can't wait to see it installed on the FJ. so we can really go play hard. :blueblob:
 

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For those new to rear ends (as I am), the stock 8.4" Toyota ring and pinion is just too small for the way we are using it.
Your rear diff is a V6 8" diff and uses an 8" ring gear. It is not an 8.4 diff. The 8.4 rear diffs were used in the T100/Tundra(pre-07). Congrats on melting that MasterCard... again. :p BTW, have Jason get the drive line work done for you. Any descent drive line shop can make the necessary yoke and length changes for you.
 

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You mean the VISA.

 

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man rear ends for trucks are like rear ends for hookers ... very expensive!

that being said it looks to be very stout
 
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Currie FJ Ford 9 Axle

As we know the FJ aftermarket is oversaturated in the suspension department, but almost no products are available for the driveline. We are breaking spindles, links and a number of us are breaking gears.

For those new to rear ends (as I am), the stock 8.4" Toyota ring and pinion is just too small for the way we are using it. There have been many broken ring and pinions - I read about one Moab run where 10% of the FJs broke theirs. We like to load up with a lot of cargo and big tires, and when wheels hop on the rocks that's it.

Currie will release a Ford 9-inch axle for the FJ, a must-have item for many of us. This gives us two state of the art choices in rear axles, including the new All-Pro/Currie Dana that just came out. This is about my day there and what I learned about this new product for the FJ.

To oversimplify, there are two primary aftermarket gear sets for factory offroad vehicles. The Dana series for crawlers, and the Ford 9 for racers. Dana pinions are 2 inches above the rear axle, and the Ford 9 is two inches below. So who wants a Ford 9? It's stronger and takes the sudden shock loads of high-speed runs better. But that clearance creates an issue over the rocks.

Edit....sounded like I was poo-pooing A2A's rear axle choice and that's not my intent.

Nice axle man. I'm sure it'll suit your needs.

Sean
 

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Thanks for the update Todd! Can't wait to see the final product.
 

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Discussion Starter #16
Edit....sounded like I was poo-pooing A2A's rear axle choice and that's not my intent.

Nice axle man. I'm sure it'll suit your needs.

Sean
Thank you very much Sean. Between you and Sol I have to keep my descriptions quite accurate...
 

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Ya, and my being a stickler for correct info comes across as being a know-it-all asshole. Not my intent at all man. I really do think the 9" is the right rear axle for your purpose, just not mine. :)

Sean
 

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Discussion Starter #19
They offered to put it in for me next week which will help them too I assume.

I forgot to mention they are offsetting it .75" to the right of stock to help it clear the gas tank just that much more. Just like Sol's Diamonds it is really something to see that huge pumpkin where before there was a tiny, shriveled... well, you know.

I asked for the regular silver gray instead of black. And of course we went over the same issues about the long travel 4-link that everybody else has. Namely, Toyota put the gas tank too close to the left upper link.

Sol and Sean, I always wondered why the bump stops are located so far inboard inside the springs. Looks like a great way to bend the housing. Jeeps have them as far outboard and close to the hub as they can get them, as you know.
 

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...I always wondered why the bump stops are located so far inboard inside the springs. Looks like a great way to bend the housing. Jeeps have them as far outboard and close to the hub as they can get them, as you know.
Thanks Todd for the write-up on the Currie 9" rear for our FJCs. I'm not sure what the intended purpose for the conical rubber stops inside the rear springs but the rear axle rubber bumpstops are located under the frame (below the shock reservoir bracket in the photo below).

 
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