Wayne Cook
July 1, 2000

Step By Step

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We used Currie’s new housing for our axle buildup. The 3-inch tubes will weld directly to the flanges on either end. These flange tubes extend into the housing a great distance and are welded inside for extra strength.
This is the new Currie 9-inch carrier casting. Reinforced in critical areas, it’s cast from super-strong nodular iron.
Looking inside of the carrier casting, you can see that the support for the nose of the pinion gear is extra beefy.
With the carrier caps in place, you can see that they definitely look stronger than stock.
Compared to the stock cap on the right, you can see how much beefier the Currie cap is on the left.
These brand-new Ford F-150 truck drum brakes should fill the bill nicely out back.
Over on the workbench, we’ve got our collection of goodies ready to go for assembly of our center section. At the left is the Currie Torque Sensing Differential. Next is the new 3.70:1 gear set above all of the various bearings and races. The new nodular carrier casting is at the top, and next to it at the right is the new Currie pinion support housing.
Our Currie technician begins assembly with a liberal dose of Loctite on the ring-gear bolts.
After the ring gear is gently seated using an air gun, and turning each bolt a little at a time, the installation is completed with a torque wrench.
This special tool is used to seat the rear pinion bearing in the carrier.
A hydraulic press seats the front bearing in the pinion support. The smooth flow of pressure avoids the banging of the hammer and insures flush seating.
The pinion seal is carefully set into place using another special tool.
When installing the pinion yoke, it’s a good idea to lube the shoulder of the pinion to protect the seal during installation.
Don’t forget this large O-ring or your fluid won’t stay around for long. The opening on the carrier is also greased to protect the O-ring.
The completed pinion assembly is now lowered into the carrier. The bolts are then installed around the circumference of the pinion and tightened to spec.
We’re back at the hydraulic press now to install our main bearings onto the Currie Torque Sensing Differential (TSD).
With the races held into position against the bearings, our TSD is lowered into position in the carrier.
These spanner nuts, which go outboard of the TSD bearings, are threaded and can be moved in or out to adjust the position of the TSD and ring gear with relation to the pinion gear. Once in the correct position, these spanner nuts are locked into place using a fastener that attaches to the main cap.
Loctite is mandatory on the main cap bolts. You certainly don’t want these fasteners coming loose. Notice how the inside of the main cap is threaded to receive the adjustment spanner nuts. The hole by the technician’s middle finger is for the spanner nut lock.
Now the main caps are installed onto the carrier. After being seated, the bolts are torqued to spec with a torque wrench.
Backlash is being checked here with a dial indicator. This important check determines the clearance between the ring-and-pinion gears.
White lead is no longer used to read the gear-engagement pattern. The white substance being used here is environmentally safe.
The technician spins the gear assembly using a power motor on the pinion nut. He pre-loads the gear set by pushing the heel of his palm against the ring gear as it spins. The result is the pattern you see here. Our setup was right on the money, and you can see that the gear contact marks are right on center in the ring gear teeth.
With our center section ready to go, it’s time to turn our attention to the housing. Here, the housing is cleaned out with a wire brush on a power drill. This will remove any remaining shot from the blasting process or any other remaining crud.
In this photo we see the weld that secures the end of the axle tube into the center section. This is one feature that makes a Currie axle stronger than the rest.
Shown here is the magnet, which is placed inside the housing of each Currie axle to trap any loose ferrous material. Also notice that gasket sealer is used on both sides of the gasket.
With the gasket in place, the center section is carefully lowered into place.
The carrier is now secured to the housing using the torque wrench. Torque specifications are followed exactly throughout the assembly.
Here we see the axle end seals being seated into position using a special tool.
It’s time for our F-150 backing plates. These are brand-new units shipped directly from Ford.
Over in a different section of the shop, our axles were being cut for 31 splines. Currie prepares all of its axles in-house using the best in machinery.
With the bearings and end plates installed on the axle, the axles can now be inserted into the housing.
When the axle splines engage the differential correctly, the end plates can be secured to retain the axle in position.
Our rear axle assembly is completed with the installation of the new brake drums. One lug nut will be added to a wheel stud to prevent the drum from moving during shipment. With our new Currie axle complete, it goes into the back of our Ranger pickup for the trip out to our ’67 Fairlane at Windsor-Fox.

With a Coast High Performance 331ci stroker and a Lentech AOD transmission, it’s a sure bet we’re going to need something stronger than a little 8-inch rearend in our ’67 Fairlane. While the 8-inch Ford axle is certainly a good unit, we’re afraid it won’t stand up to the stroker’s potential punishment. Combined with the fact that the original 8-inch is an open, or peg-leg, unit, it’s obvious we need to upgrade our rear axle.

Few in the industry can match Currie Enterprises for strength and innovation when it comes to performance rear axles, especially for Fords. Knowing this, we spoke to Ray Currie about what’s new in his product line that would work best for our application. It turns out there are several important new items at Currie for 9-inch axles that are great news for the Ford street enthusiast. More importantly, you can now build a complete 9-inch axle assembly using all Currie components. The end result is a stout piece that uses all brand-new parts with nothing remanufactured or rebuilt.

The fact is, to begin the construction of a new 9-inch axle, there are very few options available between the old, gray-iron Ford carrier casting and the high-dollar carriers designed to handle up to 1,000 hp. Nodular iron Ford carriers have all but disappeared from the boneyards, and the gray-iron Ford unit is safe to only about 350 hp. Currie Enterprises has bridged the gap with a brand-new carrier casting, available exclusively from Currie. Made from stronger nodular iron, the new casting features reinforcement in such crucial areas as the pinion bearing support and carrier caps. Never seen before now, the new Currie casting will be available by the time you read this.

The great thing about this part is that it’s far stronger than the gray-iron casting, and it’s available for a very reasonable price, in the area of $200. Now you can have a stout 9-inch carrier for your street car without the expense of a carrier that’s designed to survive a Pro Stock application.

There’s also a new Currie 9-inch housing that we used in the construction of our axle. It allows for the use of 3-inch axle tubing starting at the center section. This eliminates the need to swedge up the 3-inch tubing to 3¼ inches to fit the standard housing. Not only does it save expense, it means less difficulty when it comes time to weld on your bracketry for specific applications. There’s also an all-new, extra-strong pinion support that will also be available by press time.

For our ’67 Fairlane, we wanted an axle that is narrowed by 2 inches to allow for a larger rear tire. This would bring our width down from 57 inches to 55 inches. In order to lay down two black stripes instead of one, we specified a Currie Torque Sensing Differential equipped with 3.70:1 gears. We also wanted 31-spline axles instead of the standard 28 for an extra margin of strength because, you never know, there could be a supercharger or nitrous kit in our future. Instead of the Explorer rear disc brake setup, we decided to use the large rear drums found on early Ford Galaxies.

Currie supplied us with one better in the form of the gigantic rear drum brakes used on early ’90s F-150 trucks.