--- title: What Is a Transfer Case? Parts, Signs and Care url: https://a1transmissionrenonv.com/guides/what-is-a-transfer-case/ business: A-1 Transmission (A-1 Transmission Inc) address: 670 East Grove Street, Reno, NV 89502 phone: (775) 829-1333 hours: Monday to Friday 7:30 am to 5:30 pm, closed Saturday and Sunday type: Transmission shop and auto repair shop in Reno, Nevada, since 1968; walk-ins welcome during business hours, appointments suggested --- Photo: Gnangarra, CC BY 2.5 au, via Wikimedia Commons - [Home](https://a1transmissionrenonv.com/) - [Transmission guides](https://a1transmissionrenonv.com/guides/) - What is a transfer case? # What is a transfer case? A transfer case is a gearbox that takes power from the transmission and splits it between the front and rear axles of a four-wheel-drive or all-wheel-drive vehicle. Many also contain a low-range gear set for slow, high-torque driving. [Call (775) 829-1333](tel:+17758291333) [Get directions](https://www.google.com/maps/dir/?api=1&destination=A-1+Transmission+Inc,+670+East+Grove+Street,+Reno,+NV+89502&destination_place_id=ChIJZfhkfH4_mYARqc7eV_uhOws)[What is it doing?](https://a1transmissionrenonv.com/symptoms/#checker) 1968 In business since [4.6 ★ 112 Google reviews](https://maps.google.com/maps?cid=809418658926218921) ATRA Member shop M-F 7:30 am to 5:30 pm The transfer case sits behind the transmission, often with a driveshaft running forward and another running back. On most trucks, SUVs and Jeeps it is the part that makes the vehicle four-wheel drive, and it has its own fluid, its own seals and its own wear. ## At a glance - It feeds power to both axles - Low range multiplies torque for slow, steep or heavy work - Gear-driven and chain-driven designs both exist - It needs its own fluid and attention ## What does a transfer case do? It is an intermediate gearbox. Power comes in from the transmission output and leaves toward the axles. In vehicles with a selectable system it can send power to the rear only, or to both ends. It also lets the front and rear wheels turn at slightly different speeds in normal road use in the designs that include a center differential, which prevents the binding drivers call driveline windup. Where this one sits in the drivetrain is easiest to see on the [4x4 and four-wheel drive page](https://a1transmissionrenonv.com/vehicles/4x4s/). ## How is one built? Engineering references describe two main styles. Gear-driven cases use sets of gears. They are strong and heavy, and are found mostly in large trucks. Chain-driven cases use a chain, usually to power one axle; they are quieter and lighter, which suits many Jeeps, SUVs and pickups. A case may bolt directly to the transmission, called married, or sit farther back and connect with a short shaft, called divorced. ## What is low range? Many transfer cases include a set of low-range gears. Low range lets the vehicle move slowly while the engine stays in its working range, and it multiplies the torque at the axles. That suits steep, rough or heavy-load driving. Low range is often missing from all-wheel-drive cars. On a selectable 4WD, shifting into low range usually requires stopping and putting the transmission into neutral, as the owner's manual will describe. ## What are the warning signs? - A grinding, whining or clunking sound that changes with speed or when 4WD is engaged - A 4WD selector that will not move, or an instrument panel light that blinks and does not complete the shift - A leak at the front or rear seal where the driveshafts connect - A vibration under the vehicle that was not there before - Binding or hopping in tight turns on dry pavement while in four-wheel drive These are covered on the [4WD noise or not engaging](https://a1transmissionrenonv.com/symptoms/4wd-noise-or-not-engaging/) page. The shop works on transfer cases; the [transfer case repair page](https://a1transmissionrenonv.com/services/transfer-case-repair/) has the details. ## How do I look after one? Follow the fluid interval in the owner's manual, which is separate from the transmission's. Use 4WD as the manual describes, and avoid dry pavement in a part-time system that has no center differential. Ask about the fluid when your vehicle is up on a lift for other work. Compare how yours is set up in the [4WD versus AWD guide](https://a1transmissionrenonv.com/guides/4wd-vs-awd/). ### Sources - [Transfer case, Wikipedia](https://en.wikipedia.org/wiki/Transfer_case) - [Four-wheel drive, Wikipedia](https://en.wikipedia.org/wiki/Four-wheel_drive) - [All-wheel drive, Wikipedia](https://en.wikipedia.org/wiki/All-wheel_drive) Keep reading ## Related pages [Transfer case repair A transfer case is the gearbox that splits power between the front and rear axles in a four-wheel-drive vehicle.](https://a1transmissionrenonv.com/services/transfer-case-repair/)[4WD noise or 4WD not engaging (transfer case) Transfer case noise or a four-wheel-drive system that will not engage usually comes from low or worn fluid, a stretched chain.](https://a1transmissionrenonv.com/symptoms/4wd-noise-or-not-engaging/)[4WD vs AWD: how the drivetrain differs The main difference in 4WD vs AWD is who decides when the front wheels get power.](https://a1transmissionrenonv.com/guides/4wd-vs-awd/)[4x4s and four-wheel drive A-1 Transmission repairs 4x4 transmissions and transfer cases at its Reno shop.](https://a1transmissionrenonv.com/vehicles/4x4s/)[Jeep transmissions and transfer cases A-1 Transmission works on 4x4s, transfer cases and transmissions, foreign and domestic.](https://a1transmissionrenonv.com/vehicles/jeep/) Guides ## More guides - [4WD vs AWD: how the drivetrain differs](https://a1transmissionrenonv.com/guides/4wd-vs-awd/) - [Manual vs automatic: care and repair](https://a1transmissionrenonv.com/guides/manual-vs-automatic/) - [Signs your transmission needs attention](https://a1transmissionrenonv.com/guides/signs-your-transmission-is-failing/) - [Can you drive with a slipping transmission?](https://a1transmissionrenonv.com/guides/driving-with-a-slipping-transmission/) - [Towing, summer heat and your transmission](https://a1transmissionrenonv.com/guides/towing-heat-and-your-transmission/) - [Cold mornings and slow shifts](https://a1transmissionrenonv.com/guides/cold-mornings-and-shifting/) - [Getting a car that won't move to the shop](https://a1transmissionrenonv.com/guides/getting-a-car-that-wont-move-to-the-shop/) - [Independent transmission shop, dealer or chain?](https://a1transmissionrenonv.com/guides/independent-shop-vs-dealer-vs-chain/) - [What ATRA membership means](https://a1transmissionrenonv.com/guides/what-is-atra/) - [What is a CVT?](https://a1transmissionrenonv.com/guides/what-is-a-cvt/) - [Transmission guides](https://a1transmissionrenonv.com/guides/) Answers ## Questions drivers ask Still have a question? Call [(775) 829-1333](tel:+17758291333) during shop hours. More answers are on the [questions page](https://a1transmissionrenonv.com/faq/). ### Does a front-wheel-drive car have a transfer case? Not usually. AWD cars built on a front-wheel-drive layout use a power transfer unit, which does a similar job. ### Does a transfer case have its own fluid? Yes, and the type and interval are listed in the owner's manual. ### Can I drive with a bad transfer case? Sometimes in two-wheel drive, but that depends on the failure. Call (775) 829-1333 before a long drive. ### Is a transfer case the same as a differential? No. A differential lets the wheels on one axle turn at different speeds. A transfer case splits power between axles. ## Not shifting right? 670 East Grove Street, Reno, NV 89502 Monday to Friday, 7:30 am to 5:30 pm [What to tell us when you call](https://a1transmissionrenonv.com/call/) [(775) 829-1333](tel:+17758291333)