What is transfer case

And in the case of 4x4s , each of the four wheels need to be powered. In the simplest of terms, a transfer case will split up the engine power and send it to all four wheels using the front and rear axles. It is the center of the drivetrain system on all-wheel and four-wheel drive vehicles. Off-road vehicles may utilize a transfer case that contains one or more sets of lower gears to handle the most demanding terrain. There are many different types of all-wheel and four-wheel drive configurations, and each will require a different type of transfer case.

For instance, a vehicle that is always in four-wheel drive will have the simplest type of transfer case. A transfer case receives power from the engine and diverts it to the front and rear axles. The differential s will also aid in disbursing the power so that the car handles as well as possible.

Some transfer cases will use chains, some will use hydraulics and some will use gears. Since the s, the quest for fuel efficiency has caused manufacturers to turn to lighter materials, like aluminum and magnesium, for T-case housings. But certain aluminum housings—like the NP and NP—have earned reputations for weakness and cracking under severe-duty conditions.

This action, which occurs when you engage low-range, multiplies the torque going to the driven wheels. For effective climbing and pulling power, you want as low a low-range ratio as high a number as you can get. Most current factory T-cases have low-range ratios of between 2.

See the Ultra Low sidebar for more on these transfer cases. Single-speed transfer cases, like those found in many cute-utes and all-wheel-drive cars, are designed to split engine power fore and aft without a direct mechanical link between the two ends of the vehicle, and without any provision for low-range gear reduction.

They work fine on graded dirt roads and on wet pavement, but when the going gets tough, their abilities are limited. It used to be that almost all transfer cases fell into one of two categories: part-time or full-time.

A part-time transfer case is one that can shift between two- and four-wheel drive, allowing the driver to select the mode that best suits road conditions. In order to use a full-time transfer case on hard-packed surfaces without binding the driveline, the case must be built to allow driveline slip between the front and rear wheels.

Some like the NP contain differential gears inside the case, while others use some sort of clutch or viscous coupling between the T-case and the front driveshaft. This could indicate a low fluid level or some mechanical problem such as bad bearings, loose chains or damaged gears. Commonly, a transfer case will fail due to a low fluid level caused by leaks, a lack of maintenance or regular wear and tear. Changing the transfer case fluid on a regular basis is also important.

This can be confusing for vehicle owners who are attempting to fix their car themselves. You can contact a team member here , or by calling 08 But what happens when a transfer case goes bad?

What are the Symptoms of a Bad Transfer Case? Here we look at some of the more common signs you may find when you have a bad transfer case: Shifting Issues A common symptom of a bad transfer case is having trouble shifting between gear ranges.