The TrueTrac comes in both 28- and 30-spline versions and we chose the 30-spline. The hobbing process yields an accurate involute spline, and when done before the shaft is hardened is just about as accurate as a rolled spline. There is some crossover on the trucks, as some earlier trucks had leaves and some later trucks had the trailing arms. Both 10 and 12 bolt services are offered. Carrier Removal First, jack up the rear of the truck, support it via the frame and let the rear axle hang.
Weight Saving A number of weight-saving measures can be taken, but you must consider the safety and performance ramifications. The truck housings are not as durable as the passenger car housings due to a narrower carrier and a smaller inner pinion bearing. Once you have identified the housing, you must order the correct parts for the particular axle. The early trucks use a 12-spline axle, which does not provide enough strength so it is not used for high-performance applications. Head services Offered A complete head can be worked up for your project. Use the new spring in the disc kit.
Axles are the hardest-working component inside the housing, translating thousands of pounds of torque into forward motion and supporting the weight of the vehicle through rough street conditions. The truck 12-bolt had two factory axle sizes. Anytime you increase the spline count, the differential carrier must be upgraded to match the axle diameter of the particular shafts. The top axle is an 8. Reassembly Reassembly is basically the reverse of disassembly. Therefore, the specified pinion and ring gears must be used together. You may need to twist them a bit to realign the splines.
Most of the leading brands use 1541H alloy for 10- and 12-bolt axles. This will rotate the carrier. Install four camshaft gear cover bolts torque to 56-66 N·m 44-48 lb·ft using torque sequence as shown in Figure 15. The end result is a better traction, more power though the engine does spin a bit faster at speed because of the lower gears and all around better drivability. Every corner means that the one axle is pushing in on the wheel bearings and crossshaft pin in the differential, while the opposing axle is pulling on the C-clip.
For this build, we special ordered a new Eaton TrueTrac posi unit from our so that we would have the excellent noise-free turning and straight line traction that we need. The truck 12-bolt axles are much more affordable than the car units because they are more plentiful but these units have fewer splines so they are not as strong as the axle in the car assemblies. The differential carriers are also narrower than on the passenger car units, and they do not interchange. C-clips are located past the splines on the axle in the center of the differential, so there is nothing keeping the axle inside the tube at the end of the housing. However, only certain gear sets are offered for the carriers, especially if you change gear ratios. Note how clean my internals are.
See Chapter 2 for more detail on C-clip eliminators. Another option is to find a local machine shop that can cut splines. The 12-bolt was introduced in 1964 and installed in cars and trucks until 1972. Gears of all sizes, limited-slip or Posi-Traction, lockers, and spools are offered. Second, the metallurgy of a rolled spline determines its strength and elasticity, which is an important factor. The other potential problem is that splines have to mesh with an involute spline in the differential side gears. Thanks for explaining pinion bearing pre-load.
While we could have stayed with the open carrier and 28-spline axles with no real consequences, posi is so much better. This is achieved by heating up the axle quickly, typically by running it through a heating coil then quenching it in oil or water. Unlike the various 10-bolts, the 12-bolt axle assembly has different components for cars and trucks. To get the rear set up properly, you will need some tools — specifically, a and some. This means that in the event of an axle break, the wheel stays on the car. Aftermarket Upgrades Every car has specific needs in terms of axles, such as vehicle weight, power potential, tire size and type; even the elapsed time for drag racers factors in to the final determination.
I will be replacing the bearings and axles if needed. Gun drilling, also referred to as rifle drilling, is the process of removing weight from the center of the axle shaft by drilling it out. Remove four camshaft gear cover bolts. The molecules of the metal align, becoming denser, and thus the metal is stronger. A bad wheel bearing will make a loud howling sound when the vehicle is driven. Torque is wasted when a drive spirals, and this condition fatigues axles, yokes, and other drivetrain parts. However, the smaller 10-bolt unfairly gained the reputation as a weak and inadequate rear end for high-performance applications.