Installing a Currie Ford 9" in a Tacoma

Tired of breaking shit with your heavy truck, big tires, and a shitty 8" Toyota rear end? I know I was. Fortunately Currie came out with a couple of fabricated housing options specifically for our rigs: A F9 unit and a RockJock Dana 60 unit.

https://www.currieenterprises.com/TA-F9325R
https://www.currieenterprises.com/ta-rjiiir-2

Both of these units are about as close to bolt-in housings as you can get off the shelf. I say "mostly" because a lot of the hard work is already done, but they are still a builder part. Some fabrication and definitely mechanical work is required. The kit is intended to re-use some factory parts including the stock Tacoma drums. The outer housing ends of the Currie housing accept the Tacoma axle bearings to reuse the factory speed sensors and drum brakes. Now it's really up to the owner, rig, and driving style to decide which axle to go with. I personally went with the F9 housing because it suits my needs. If you want to read all the nitty gritty reasons, take a look here: https://www.tacomaworld.com/threads...-a-tacoma-build.455075/page-119#post-17132583

You can read the overview of the rear end units in the links above. But in short, the unit will ship with the housing, custom axles, bearings, bearing retainers, and oil seals. You will need to pick your favorite vendor and setup for the third member (if you go with the F9), fabricate and weld your own shock mounts, and cannibalize some parts off your factory housing. There are upgrade options as well with the Currie housing. I had mine upgraded to 3.5" axle tubes, back brace/truss, desert skid, fill/inspection port, and with a 68" WMS-WMS width instead of the stock 65.5" (to better match the width I have with the +2 Total Chaos long travel kit up front).

So the whole reason I went this route is because I ended up shearing the driver's side axle shaft and put a fairly obvious torque bend in the shaft itself. R&P and side gears were all fine, but the axle was far was happy with me.





Part of my goal with the new housing was to be able to sell the old axle as a drum to drum roller. Obviously the sheared axle shaft is going to break the value of that down, but I still didn't want to go through the process of removing the old drum backing plates and all the bullshit off the stock shafts. I also took this as an opportunity to get rid of the drum brakes. So I reached out to SOS Performance (same company I have for the Big Brake Kit on the front of my truck). SOS has a a few disk conversion kits available, one that uses 4Runner rear disks, but they also has a Big Brake Kit that uses Stoptech calipers and components for the rear and retain e-brake functionality. I'm stupid, so naturally I went with the BBK and went ahead and did his Sequoia master cylinder kit. The sequoia MS is properly proportioned for calipers in the rear rather than wheel cylinders.
https://sosperformance.com/products...sion-with-parking-brake-fits-2005-2015-tacoma
https://sosperformance.com/products/2005-2017-toyota-tacoma-master-cylinder





I ordered my third member from ECGS. I've used them for a lot of gear work over the years and have had nothing but good interactions with them. Nodular Yukon case, 35 spline, big bearing, billet Daytona pinion support, billet 1350 yoke, ARB air locker, and 4.86 gears.





Axle Assembly

As mentioned, the new housing will come with custom axle shafts. These axle shafts are 35 spline and come with the 6x5.5 bolt pattern lug studs pre-pressed in. Again, if you are going to be retaining some of the stock axle parts (drum brakes), you will have to canibalize some parts. Take a look at the diagram and markings below (compliments of @tetten).



As you can see from the markups, Currie will include the bearings, bearing retainers, axle shafts, and the lug studs. Everything else you will have to cannibalize from your stock housing, or order separately from Toyota. Now since I didn't want to disassemble my axle shafts, and I didn't reuse the stock brakes, and I wanted to keep the stock axle as much of a roller as possible, I decided to just buy the extra parts I needed from Camelback Toyota. The parts needed are as follows:

90208-44001 Axle Shaft Bearing Washer x2
90520-41019 Snap Ring x2
42443-60010 Oil Deflector Gasket x2
42441-35060 Oil Deflector x2

The snap ring and gasket you should buy new no matter what as they are considered non-reusable parts. But that's for you to decide. In total the parts were less than $50 which was well worth it for me to not have to press out the old bearings from the stock shafts to get those parts out.

The new Currie shafts have the lugs pre-pressed in. In order to install the oil deflector and gasket, you will need to press out the lugs.



Once the studs are out, you can install the oil deflector and gasket. One thing to note, the knurl on the Currie studs are slightly larger than OEM Toyota studs. So the oil deflector started to deform when pressing the studs back in. So to prevent that, I drilled the oil deflector holes out with a step bit one size up and then pressed in the studs.







The next step is to press in the new bearings, washer, and bearing retainer. It's important to note that each one of these parts is DIRECTIONAL. Meaning if you install it the wrong way and then press it onto the shafts, you're going to have to order new parts. The don't come off easy. So don't fuck this part up. Also you will see pictured my disk backing plates. Obviously if you are retaining the drums, you'll have the drum backing plates that will need to go on first. Assembly order is pictured in the above diagram, but in short it's drum backing plate, then bearing, then washer, then bearing retainer, then c-clip. The washer is slightly conical shape. The cone shape itself should be facing towards the snap ring (facing upwards as in my photo below). The bearing retainer is chamfered on one end. The chamfered end should also face towards the snap ring (again upwards as pictured).









Once all that crap is put in the correct order and direction, it's time to press everything in. I used a 20 ton Harbor Freight press to do the dirty work. To protect the bearing retainer and to distribute the load as everything gets pressed in, I used a pipe fitting. A piece of 2" .120 wall DOM will also work. And to protect the axle face itself, I stacked up a few pieces of scrap steel. Then it's just a matter of putting the press to work little by little until the snap ring groove is exposed and you can install the snap ring. Once that's done, the axles are ready for install.







Housing & Third Member

Nothing overly complicated here. However I was not a fan of the drain option that Currie offers. It just hangs too low. So I removed one of the studs off the bottom of the housing. The housing itself is just drilled/threaded for the studs with nuts on the inside. So I welded a nut on the inside of the housing and using a standard bolt that will be removed when it's time to do gear oil changes. Simple solution Ford 9" guys have done for years.





Then it's just a matter of installing your gasket (I went with a Lube Locker instead of the shitty felt and RTV), skid plate (if applicable), and you're off to the races. One thing I will note, the inspection port came in pretty handy for the install. The copper line used for the ARB is a really really tight fit going into the housing. I had to slightly move the copper line through the inspection port after install to ensure it didn't come in contact with anything. If you're going to add just 1 upgrade to your Currie housing, make sure it's the inspection port!

https://youtu.be/ksuVwuVCAtE

Now's where the fun starts. Remove the old axle from your rig. You can do this however you want, but it was easiest for me to drop the whole axle as a roller. It also made for a strategically timed Instagram post subtly making fun of the third gen guy who lost his whole axle off-road...in the worst recovery method I've ever seen in my life...but I digress.





Once the old shit is out of the way, you can start assembling all the new goodies. Now I already mentioned the housing does not have shock mounts. Wouldn't matter for me anyways since I did my own shock hoops/relocation for 12" triple bypasses. As such, I also like to cycle my leaf packs to get proper bump and droop before welding in the lower shock mounts, so that's why you will see just a single leaf rather than the whole pack in some of these pix. I also took the opportunity to to upgrade to 5/8" u-bolts. The truss unfortunately was designed for 9/16" u-bolts. Nothing some quick work with a drill didn't resolve though. Also I needed new u-bolt plates to accommodate the larger (and wider) u-bolts. So Eric at @RelentlessFab cut me out some new u-bolt plates out of 1/2 steel...because why the hell not?!?! After that, just get your suspension cycled and set your shock mounts up.





Currie will send two new axle seals that need to be pressed into the outer flanges of the housing. Straightforward as any axle seal, just press them in so they are flush.





So the disk brake kit from SOS is pretty clever. It retains e-brake functionality similar to how the 4Runners are set up. That is you have a rotor with calipers and pads for the normal brakes. But inside the rotors are mechanical shoes that are used to press outward for an e-brake. It all uses the factory cables, just need to take out some slack in the adjustment under the center console.



The Sequoia MS setup is pretty strait forward. Out with the old, in with the new and the adapter plate. The outlet ports are on the opposite side of the Tacoma MS, so they do include adapter brake lines, but you will have to bend them yourselves. A metal Tepui fest cup worked perfect for me to use to bend the lines around.







Something to note is that the truss is hollow inside and dirt, mud, and shit can get in through the u-bolt holes and corrode it from the inside out. To combat this, I did the same thing I did with the truss I had on the Tundra axle I had on my first gen. And that is fill the truss and gaps with expanding foam you can get from any hardware store. When it dries, you just cut off the excess and run your drill through the foam for the u-bolts. It keeps out the vast majority of the shit out of the hollow voids.





Brake Lines, Speed Sensors, Breather, and Air Line

Nothing on the housing from Currie is tabbed for any of the brakes, or sensor wires. It does come with a driver’s side diff breather, so if you've already done a diff breather relocation, you are golden here. My old breather reroute slid right onto the breather nipple provided in the new Currie housing. But for the rest of the stuff, you as the builder make the decision how to route things. For the brake lines, I cut off the landing pad on the stock housing and welded it to the truss roughly in the same place on the housing (driver side of the pumpkin). Now given my axle is wider than stock, you definitely have to get a little creative if you want to reuse the brake lines that were on the stock housing. The lines were long enough, but I had to remove some of the bends and make some different bends to accommodate the new routing. Not difficult, but time consuming. Speed sensors were an even tighter fit. The axle tubes themselves are notched on the fore and aft side so the speed sensors can be placed either on the front or the rear of the axle. With the SOS kit, you're only choice is to clock the bearings so the speed sensors will install on the front side of the axle. There's no room on the rear. Again since my axle is wider, i had just enough slack to route the sensor wires without having to extend them.











https://youtu.be/7oUbXD55Eic

The last bit is again a bit of a builder decision. I wanted a 1350 yoke on the third member, but also like the flexibility of the 1330 u-joints used in Toyota driveshafts. So I got a crossover u-joint which converts the last 1330 u-joint in the driveshaft to half 1330 (connected to the Toyota driveshaft) but the other half of the u-joint is 1350. The last flange of the driveshaft is removed with this route.

$40 Spicer 5-648X U-Joint Kit 1330/1350 Series (OSR)

https://www.amazon.com/gp/product/B00CXAMVNO

Physically this all bolted up. But there just isn't enough length in the slip yoke. I've got less than 1/2" of splines that are actually engaged in the slip yoke. So...as of the time of writing this, I'm going to have the second half of the driveshaft extended and balanced to put the slip yoke back where it's supposed to be. I've got a local gear and driveshaft shop that's re-tubed, shortened, balanced various driveshafts in the past. Plan on at least $150 for the driveshaft work.





Bleed the brakes, fill it with fluids, and hit the road. Piece of cake...right?

Oh and make sure to torque everything down. Nobody wants to be this guy.....

 

When you get the driveshaft lengthened you can get whatever end you want put on. I will caution that although the 1350 is stronger, it doesn't have as much angle of dangle as a 1330.
I'll let my driveshaft guy figure out what's best and go from there. That's the only outstanding thing I have to do (I think).

 

High pinion with a 9" is the wrong decision for what I put my truck through. The high pinion design itself is inherently weaker because it runs on the coast side of the gear and nobody in the world cuts gears that are drive side engagement. And because it's reverse cut, general consensus is expect a 20% loss in strength by comparison. It actually pushes the pinion gear away from the ring gear. Some manufactures have tried to address this by putting a thrust block behind the ring gear with "mixed" results. If it's setup properly, it should prevent gear deflection, but it takes a special kind of builder to set that up right. And because it's so high, you don't get proper lubrication on the pinion gear. You need an extended shroud inside the housing and a ring gear cup that goes to the pinon support. All these are extra variables and more shit that can go wrong. Not my cup of tea.

 

Yeah fronts are different. If you are set on a rear high pinion, definitely go with the Dana 60.