A complete Currie 9-inch third member makes updating your street rod, muscle car, or truck with a new gear ratio or performance differential. All Currie built-to-order third members feature a new gear case, bearings, seals, solid pinion bearing spacer, and Daytona pinion support, with a choice of gear ratio, pinion yoke, and differential type.
Currie 9-inch third members are assembled by our in-house experts, who have decades of rear end setup and assembly experience, so you can trust the finished product.
Product Features:
Iron Gear Case
The Currie nodular iron Race case features additional material and webbing for a rigid design that minimizes gear deflection, reinforced material around the pilot bearing, and solid billet adjuster nuts, ensuring exceptional stability and durability
Iron Pinion Support
Currie nodular iron Daytona big-bearing pinion support increases load capacity and improves oil capacity with maximum strength and rigidity
Aluminum Pinion Support
Currie aluminum Daytona big-bearing pinion support, all the features of our iron pinion support in lightweight aluminum with a red anodized finish
Aluminum Gear Case
The HD Pro aluminum case features 9/16 through-bolt main caps for enhanced strength, a robust forged aluminum pinion support with high-flow oil passages, and a load bolt designed to limit gear deflection and maintain precise gear engagement
Master Bearing Kit
High-quality Timken or Koyo bearings and performance seals are used throughout to provide a long, trouble-free service life
Gear Ratio
Select from a wide variety of ratios, Currie uses only the highest quality Motive Gear Performance® series (Orange box) ring and pinion sets
Differential
Select the differential type that meets your traction needs, including helical gear limited-slip, automatic locking differential, or steel spool
Pinion Yoke
Select from a range of pinion yokes, including nodular and or billet Chromoly
Fully Assembled
Fully assembled and set up in-house by skilled professionals
DIFFERENTIAL OPTIONS EXPLAINED
Currie TwinTrac, Truetrac, and Wavetrac - Helical gear limited-slip type differentials (HGLSD). The HGLSD is the modern replacement for the classic clutch-style limited-slip. When cruising, HGLSDs function like a standard or open differential, allowing one wheel to spin faster or slower as necessary without the noise or stick-slip frequently experienced with clutch-style limited slip or automatic locking differentials. Under acceleration, if a wheel loses traction, the helical gears inside the differential automatically engage, transferring torque to both rear wheels. When the wheels regain traction, the HGLSD seamlessly transitions back to functioning as an open differential. Unlike the traditional clutch-type limited-slip, HGLSDs require no special oil additive or maintenance to replace worn and tired clutches. HGLSDs have no wearable parts, require no special oil additive or maintenance, and maintain their as-new functionality for life.
ARB Air Locker - The ARB is a selectable locking differential that allows the driver to positively lock or unlock the differential on demand with the flick of a dash-mounted switch. An onboard air compressor (sold separately) is used to apply the locking force. Once locked, the differential behaves like a spool, driving both wheels equally. When unlocked, the locker acts like an open differential, driving only one wheel at a time – usually the wheel with the least traction. The key benefits of the ARB Air Locker are its predictable behavior and legendary strength.
Detroit Locker - Automatic locking differential, designed to automatically lock and unlock when torque is applied in either a forward or reverse direction. When locked, it acts like a spool, driving both wheels equally. When coasting or rolling into a corner (no torque applied), the Detroit Locker unlocks and momentarily operates like an open differential, permitting the wheels to rotate freely. When torque is applied, exiting the corner, the unit locks and drives both wheels equally. The key benefits of the Detroit Locker are its rugged construction and superb performance. The only negative is that the automatic lock and unlock operation can create a clunking sensation that can be felt and heard in the vehicle.
Spool -The spool is the most straightforward and robust option, but it lacks differential action, as both axles are joined together by the spool's solid center. Spools are not recommended for the street, as they place high twisting loads on the axles, increase tire wear, and negatively impact handling. Theyare typically only used for drag racing applications where straight-line performance is the only concern.
NOTES:
Lubrication Requirements - 9-inch rear-ends use a high-offset hypoid gear design that requires a severe duty 85w-140 gear oil with API GL-6 rating. Use of oil not meeting the GL-6 rating will damage the gears and bearings and void the Currie Warranty
FAQs
Pro Race 35-Spline Axles (up to 1000 hp1) Recommended for drag-race-only use. Requires 3.250”-bore case with appropriate gear carrier; locker or spool. Pro Race 40-Spline Axles (1000 hp1 and up) Recommended for drag-race-only use.
What is the difference between a 35-spline and a 40 spline? ›
The distance between the centerline of adjacent splines remains constant, so as the diameter of the shaft increases, so does spline count. For example, a 35-spline axle has a major diameter of 1.500 inches; a 40-spline axle is 1.708-inches in diameter.
What is the spline count on a Ford 9-inch rear end? ›
Factory axle shaft and differential spline count is 28 and 31, although aftermarket axles with 35 and 40 spline count are readily available from reputable manufacturers.
What is so special about a Ford 9-inch rear end? ›
The iconic Ford 9-inch has been the go-to diff for hot-rodders since day one. The brilliance of the unit is its ability to hold power, its quickness in changing gears, its vast range of available gear ratios, and the ease in which it can be setup. Shop our Ford 9-inch differential products here.
Are more axle splines better? ›
Spline Length
Some manufacturers, in an effort to cut costs, "gang run"quantities of axles with very long splines. Then, they merely chop off the required amount of spline to get the desired length. Accordingly, some axles have very long splines (which weakens it) or very short splines (which compromises engagement).
What is the diameter of a 35 spline axle? ›
As an example, a 35-spline axle has a major diameter of 1.500-inches while a 40-spline axle measures 1.708-inches in diameter.
What is the most popular spline size? ›
For standard screening material, 0.140” and 0.160” spline are the most commonly used sizes. For thicker screening products, 0.125” is the most common.
What spline axles do I need? ›
Any car worthy of a 9.99 or better elapsed time should be equipped with 35-spline axles at least. Heavier cars, or those with an anticipated load of 9,000 lb-ft should have nothing less than 40 splines. For bracket and street use, avoid OE 28-spline axles; in fact, even 31-spline axles are borderline.
What is the difference between spline and B-spline? ›
Splines are a large class of methods. The method of B-splines is a simple method for taking a single covariate and expanding it such that it spans the set of all functions that are a polynomial of degree d between all the given knots and d−1 differentiable everywhere.
How much horsepower is a Ford 9 inch rear end rated for? ›
"They're good only to 400hp max," says Tom at Tom's Differentials. "Anything above that should use today's beefed-up, redesigned, nodular-iron aftermarket cases. They're good to 800 hp, if built properly. The next step beyond that would be the high end, completely redesigned, Mark Williams billet-aluminum housing.
Note; On a 9 inch Ford, a centered housing [equal length tubes] gives a pinion offset of 1 inch to the right [passenger side].
Are all Ford 9 inch rear ends the same? ›
We should point out there are three distinct 9-inch axle ends: the late big bearing (Torino) and the early big bearing both take a 3.150-inch od wheel bearing (the difference is in the bolt spacing for the backing plates), the small bearing ends take a 2.834 od bearing with yet a different backing plate bolt pattern.
What is the best Ford rear end for racing? ›
The dependable 9 inch Ford rear end has by far the widest application reach. Strange offers an impressive array of internal performance parts, Ford 9 inch spools, ford 9 pinion supports, and ford 9 gear sets to build industry-leading complete drag racing rear ends.
Why is the Ford 8.8 rear end so popular? ›
The biggest reason is there are thousands of Fox-body Mustangs with 8.8 rearends in boneyards all over this country that can be easily purchased for $100 or less.
What vehicle came with a Ford 9 inch rear end? ›
The Ford 9-inch rear end, so named because of its 9-inch ring gear diameter, was manufactured from 1957 to 1987 by the Ford Motor Company and installed in some intermediate and most full-size Ford, Lincoln, and Mercury passenger cars, F-Series ½-ton trucks, and Econoline vans.
How many splines does a Dana 35 have? ›
A couple of things, the new Dana 35 rear is a 29 spline axle (The old original Dana 35 was only 27 spline for reference).
How many spline axles do I need? ›
What does Williams' recommend? Any car worthy of a 9.99 or better elapsed time should be equipped with 35-spline axles at least. Heavier cars, or those with an anticipated load of 9,000 lb-ft should have nothing less than 40 splines.
What is the difference between 28 and 31 spline axles? ›
The obvious differences in 28 and 31 spline axles will be the number of splines! When you count the number of teeth (splines) on each axle, you can find out which option you have. 31 Spline Axles also tend to be larger in diameter to accommodate the increased amount of splines.
How strong is Dana 60? ›
The newest OE kingpin Dana 60s have a gross axle weight rating (GAWR) of as little as 3,660 pounds, while a modern ball-joint Dana 60 has a GAWR of nearly double that. Not only are OE kingpin knuckles weaker, they are more expensive and more difficult to service than ball-joint knuckles.
