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Frequently Asked Questions

Find answers to the most asked questions about your purchase, order or shipping

General questions

Normally the flow of power goes from the transmission to the rear wheels through the driveshaft. However, when you shift into 4WD that power has to be split between the front  and rear wheels. The transfer case makes this split happen. When you shift into 4WD, gears are engaged to power a chain drive that runs from a gear driving the rear driveshaft to power another set of gears behind the front driveshaft. Once engaged, this driveshaft delivers power to the front differential and out to the front wheels.

The ID tag location varies by manufacturer.

New Venture – Round tag on the back of the unit.

Borg Warner – Tin tag located on the case half bolts.

Magna – Sticker that can be found in a few different locations on unit.

Transfer cases use a combination of Drive, Housing, and Shift Types.

Drive types:

Gear driven transfer cases use a set of gears to send power to the front and rear axle. While gear driven transfer cases are more durable, they are also louder and less practical for smaller vehicles because of their weight.

Chain driven transfer cases use a chain in place of a gear set. Though most chain driven cases only drive one axle, there are case systems designed to drive both axles with a chain. Chains are lighter and quieter, but weaker than gear sets.

Housing types:

Married transfer case housings are bolted to the transmission, often between the output shaft and the main driveshaft. Some married transfer cases share their housing with the transmission.

Independent housings are installed separately from the transmission casing and are connected to the transmission output shaft with another driveshaft.

Shift types:

Manual Shift On-the-Fly (MSOF) transfer cases are controlled with a lever on the driver’s side floor of most vehicles. These transfer cases have two automatic sealed front axle hubs or two manual front axle hub selectors. High 4WD settings can be engaged at low speeds, but low 4WD settings must be engaged when the vehicle is stationary and the transmission is in neutral.

Electronic Shift On-the-Fly (ESOF) transfer cases have a dash-mounted selector, usually a switch or set of buttons. These cases have sealed automatic locking front axle hubs and a transfer case motor. High and low 4WD is engaged in the same ways as a MSOF transfer case.

First, let’s consider a rebuilt transmission. In most cases, a vehicle experiencing transmission problems is brought to an automotive repair shop. There, the transmission is removed and worked on by a mechanic who completely disassembles the transmission all the way down to its component nuts and bolts.

The mechanic inspects and cleans each and every transmission component and determines which parts are in working order, excessively worn, or just plain damaged beyond repair. Parts deemed worn or damaged are replaced with new or “used” components, and the unit is then reassembled. Once completed, the transmission is reinstalled and the vehicle is ready to hit the road. In this scenario, the transmission has been “rebuilt” – repairs have been made, bad parts have been replaced, but the unit has received few, if any, upgraded components.

A remanufactured transmission is basically the same as a rebuilt transmission, but the work has been performed by a dedicated transmission repair facility or shipped to the original transmission manufacturing facility. By opting for a transmission remanufacture, the customer is assured the transmission is being repaired by absolute experts on that particular transmission and has been remanufactured to incorporate all design and component upgrades that weren’t available when it was originally manufactured. This example also applies to transfer cases and differentials.

For vehicles made after 1995 it’s recommended to look in your owner’s manual for part number and description. If using non-OE oil, make sure the fluid you use states that it is a direct replacement for the OE part number. If the fluid meets or exceeds OE specs but does not cross to the OE number, do not use IT  and look for one that does.

High stress driving will repeatedly increase the temperature of your transmission, eventually breaking down the stability of the gear oil in your car. If you regularly tow, drive in low traction conditions, or drive in mountainous regions, you will likely need to change your gear oil every 30,000 miles, or potentially even less.

In normal driving conditions, most cars can travel up to 80,000 miles before needing a gear oil change. However, this number is a maximum, and most manufacturers recommend changing your gear oil between 50,000 and 60,000 miles.

Other conditions that require a gear oil change can develop under unusual circumstances. For example, if your transfer case, differential component, or transmission has experienced submersion in water or another foreign fluid, your gear oil should be replaced. Contaminated oil can seriously damage your gearbox, transfer case, or differentials with inadequate lubrication.

You should also replace your gear oil if your transfer case or differentials recently had a leak repaired. A leak could signal contamination or low levels of gear oil. Most mechanics will replace your gear oil after repairing a leaky component, but this is sometimes forgotten during home repairs.

Lastly, if you or your mechanic finds dirty gear oil during a checkup, it should always be replaced. Old or dirty oil leads to destabilized viscosity and poor lubrication, which will prematurely damage your gearbox, transfer case, and/or differentials.