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Transfer cases are an integral component of your vehicle’s drivetrain, providing power transfer between front and rear axles.
Four-wheel drive and all-wheel drive vehicles rely on axles with differentials for improved traction on dirt surfaces, while off-road vehicles use them to increase grip in soft environments like sand or snow.
Input Shaft
The input shaft is one of the key components in a transfer case, responsible for transmitting power from an engine to its main drive gear and transmission system. Usually when engaging the clutch, this shaft spins at equal speed with engine.
Transfer cases are the heart of any four-wheel-drive system, as they transfer power from the engine to both front and rear drive shafts. There are many variations available to meet specific performance and wear-reducing goals on vehicles.
Most transfer cases on the market are typically composed of either cast iron or aluminum. While cast iron cases tend to be more durable and resilient to internal component failures, they also weigh considerably more and are vulnerable to damage by frequent bending and flexing in tight spaces or rough road conditions.
Aluminum cases tend to be lighter, yet can also have wear issues and can be hard to replace; not an ideal situation for any truck owner.
No matter the material chosen, transfer cases must be designed to handle an enormous amount of torque. Therefore, they typically utilize rotating gears that mesh seamlessly together as well as with their output shaft.
The input shaft gears are permanently meshing with their respective countershaft gears, so the speed of the output shaft depends on which countershaft gear is engaged with it. There are multiple output shaft gears connected to different countershaft gears; you have five possible gear combinations to select from when selecting output shaft gears for output shaft use.
Some transfer cases use an output shaft differential, which allows one of the output shafts to spin at a slower rate than the other and helps the transfer case maintain alignment over uneven surfaces while avoiding driveline bind. Some also feature fifth gearing capability which enables greater power delivery when necessary.
Output Shaft
The Output Shaft is an integral component of a transfer case that connects power from its transmission to four-wheel drive vehicles’ rear axles. Located inside the transfer case housing, this component uses other parts such as its yoke sleeve to transfer energy efficiently between transmission and rear axle.
This output shaft is a two-piece drive shaft constructed of front and center slip yokes which are bolted together on an output shaft seal that slides laterally on an output sleeve that has been secured within the transfer case housing with snap rings. When driving occurs, fluid may escape through these slots into the transfer case housing through which this output shaft travels – however this seal remains in constant contact with it to prevent fluid from seeping into it and out.
An output shaft in a typical transfer case connects to an array of gear reductions and chain drives that adjust the amount of torque sent to rear and front drive axles, and reduce the force sent directly to them, enabling vehicles to switch seamlessly from two-wheel drive neutral to low or high four-wheel drive without losing all power.
Each free gear on the output shaft is matched to a countershaft gear in constant mesh with it, producing different ratios for every gear. In addition, there are some “free” gears on the shaft which do not need to be matched up with another countershaft gear.
The output shaft contains six free gears which rotate at various speeds depending on their relative size to that of their powering countershaft gear, creating six individual gear ratios for each of its six gears.
As output shaft gears wear down over time, they no longer properly engage countershaft gears causing your vehicle to toggle in and out of all-wheel drive. Furthermore, if an output shaft seal becomes damaged or eroded it could result in some unusual noises being heard underneath your car – usually an indicator that this component needs replacing.
Driveshaft
A driveshaft is an integral component of your transfer case that transfers power from the transmission to your front and rear axles, providing power distribution across rough terrain. Its purpose is to distribute engine torque evenly among all four tires for optimum vehicle control.
A drive shaft can either be single-piece or two-piece design. Single-piece driveshafts usually consist of a yoke attached by universal joints to a drive shaft; U-joints help maintain proper angles between these components as well as with transmission and differential systems.
U-joints are an integral component of driveshafts as they allow free movement by using bearings. Over time however, these bearings may wear down and need replacing;
Couplers are an essential component of driveshafts. These connections connect the drive shaft with transmissions and differentials as well as front and rear driveshafts; any worn out couplers could cause your driveline to shake and vibrate, making controlling your vehicle difficult.
Lubrication of both your driveshaft and transmission are necessary components for their optimal operation, as both require grease to operate effectively. Scheduling regular services at a mechanic can help avoid issues like clunking, squeaking or shuddering in your vehicle.
Your mechanic can also inspect the condition of your u-joints and carrier bearings to give you a more accurate assessment of how healthy your driveshaft is. Faulty joints or worn bearings could cause vibration in your driveshaft that makes turning unevenly difficult while making controling it challenging.
There are different kinds of transfer cases, including both gear driven and chain driven ones. Both use gears to transmit power from front and rear axles; however, gear driven transfer cases tend to be more durable and louder.
Married transfer cases attach directly to a transmission, usually between its output shaft and main driveshaft. They’re the most frequently found type of transfer case; however, there are divorced and independent versions as well.
Shims
A shim shaft is a thin piece of metal designed to fill in holes or gaps, and is an invaluable asset when working on vehicles with transfer cases. Shims can help increase output shaft accuracy, helping your car more smoothly shift gears between gears.
Shims are essential components of transfer case assemblies, from the output shaft to air cylinder and piston seal components. Shims ensure fluid flows freely while helping protect against wear-and-tear on the transfer case itself.
According to their application, shims can take various forms and sizes, typically made of aluminum, brass, or carbon fiber. For optimal use, lightweight shims are preferable as they’re easier to manage and install – typically about one inch long by 0.1 inch thick.
Shims are commonly referred to as ferrules or adapters; however, they’re technically part of a hosel and provide a cost-effective and simple way of increasing performance of a hosel.
Brass shims come in two sizes, the standard version weighing in at approximately 1.6 grams while an oversize one comes in just below one gram. Both sizes offer some cool features such as magnets to hold them in place when not being used.
Are you looking to upgrade the performance of your hosel? Look no further – our selection of transfer case parts provides everything necessary to bring back a smooth operation of your vehicle and restore its hosel to original shape.