--- title: 4WD Noise or 4WD Not Engaging: Transfer Case | A-1 url: https://a1transmissionrenonv.com/symptoms/4wd-noise-or-not-engaging/ 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 --- - [Home](https://a1transmissionrenonv.com/) - [Transmission symptoms](https://a1transmissionrenonv.com/symptoms/) - 4WD noise or 4WD not engaging (transfer case) # 4WD noise or not engaging Transfer case noise or a four-wheel-drive system that will not engage usually comes from low or worn fluid, a stretched chain, a worn bearing or shift fork, or a faulty electric shift motor or switch. The transfer case sits behind the transmission and splits power between the front and rear axles. [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 Call before you drive it far In two-wheel drive it may be fine for short trips, but call before you rely on it in snow or on a trail. A grinding or whining noise that is present in 2WD too, or a flashing 4WD light, means keep driving to a minimum. Short, gentle trips only. Call (775) 829-1333 and describe what it is doing before a highway drive or a long trip; a problem like this can get worse with heat and load. ## Common causes - Low or worn transfer case fluid The case has its own fluid supply, and a leak or long service gap leaves bearings and chain short of lubrication, producing whine and wear. - A worn chain, bearing or shift fork Chain stretch, rough bearings or a worn fork cause growling, clicking or a case that will not move into the range you select. - An electric shift motor, switch or encoder fault Many newer vehicles shift with a small motor and a position sensor. When it fails, the light flashes and the vehicle stays in the mode it was in. - Front axle or driveline engagement trouble Hubs, a front differential actuator or a vibrating driveshaft can mimic transfer case noise and make 4WD seem not to engage. Many drivers only find out their 4WD has a problem when they need it, on a snowy morning or a dirt road. A transfer case is an intermediate gearbox that passes power to both axles, sometimes with low-range gears for off-road use. Reno gets about 5 inches of snow in each of January and February. ## At a glance - The transfer case sits between the transmission and the driveshafts - Chain-driven and gear-driven cases fail in different ways - A light flashing on the 4WD switch is useful information - Fluid in the case is separate from the transmission fluid ## What the transfer case does In a part-time 4WD truck, the transfer case lets you send power to both axles or only the rear, and on many it adds a low range for crawling. Inside there is either a chain or a set of gears. If you want the bigger picture, the [what is a transfer case](https://a1transmissionrenonv.com/guides/what-is-a-transfer-case/) guide covers it, and the [4WD vs AWD](https://a1transmissionrenonv.com/guides/4wd-vs-awd/) guide explains the difference. ## Reading the symptoms | What you notice | When | Where it often points | | --- | --- | --- | | Whine or hum | Changes with road speed | Low fluid, bearings or chain | | Clicking or ticking | Slow speed in 4WD turns | Tight-turn binding or a front axle joint | | Grinding when shifting | Moving the 4WD selector | Fork, synchronizer or low fluid | | Selector moves but nothing happens | Any speed | Shift motor, cable or internal failure | | Light flashes on the 4WD switch | After you press it | Position sensor or motor fault | ## Winter in Reno Reno's normal January snowfall is 5.2 in, with a normal low near 26.1 F (NOAA), and the roads toward Truckee or Carson Valley can change fast. A 4WD that has been unused all summer is more likely to show a seized fork or dry bearings on the first snowy morning. If you have not used it recently, try it in a safe place before you need it. ## Trucks and Jeeps The [4x4s and four-wheel drive](https://a1transmissionrenonv.com/vehicles/4x4s/) page and the [Jeep transmissions and transfer cases](https://a1transmissionrenonv.com/vehicles/jeep/) page cover the vehicles where this comes up most. The shop lists transfer cases among its services. ## Before you call - Follow your owner's manual for engaging 4WD, which for many vehicles means a particular speed and gear. - Note whether the noise is also there in 2WD. - Look under the vehicle for fluid near the middle, and take a photo. - Write down what the 4WD light or message does when you try. ### Sources - [Transfer case, Wikipedia](https://en.wikipedia.org/wiki/Transfer_case) - [Four-wheel drive, Wikipedia](https://en.wikipedia.org/wiki/Four-wheel_drive) - [NOAA NCEI U.S. Climate Normals 1991 to 2020, Reno-Tahoe International Airport](https://www.ncei.noaa.gov/products/land-based-station/us-climate-normals) Keep reading ## Related pages [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.](https://a1transmissionrenonv.com/guides/what-is-a-transfer-case/)[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/) Services ## Work that fixes this [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/)[Transmission diagnosis Transmission diagnosis is the step where a mechanic finds out what is actually wrong before choosing a repair.](https://a1transmissionrenonv.com/services/transmission-diagnosis/)[Auto repair and maintenance A-1 Transmission in Reno is a transmission shop that also does general auto repair and maintenance for cars, trucks and SUVs.](https://a1transmissionrenonv.com/services/auto-repair-and-maintenance/) Symptoms ## Other symptoms - [Clutch slipping, grabbing or hard to press](https://a1transmissionrenonv.com/symptoms/clutch-slipping-or-grabbing/) - [Transmission slipping](https://a1transmissionrenonv.com/symptoms/transmission-slipping/) - [Hard, harsh or late shifting](https://a1transmissionrenonv.com/symptoms/harsh-or-late-shifting/) - [Delay when shifting into Drive or Reverse](https://a1transmissionrenonv.com/symptoms/delayed-engagement/) - [Whining, grinding or clunking](https://a1transmissionrenonv.com/symptoms/noise-whining-grinding/) - [Transmission fluid leak (red or brown fluid)](https://a1transmissionrenonv.com/symptoms/fluid-leak/) - [Burning smell](https://a1transmissionrenonv.com/symptoms/burning-smell/) - [Check engine light and transmission codes (P0700-P07xx)](https://a1transmissionrenonv.com/symptoms/check-engine-light-transmission-codes/) - [Won't go into gear](https://a1transmissionrenonv.com/symptoms/wont-go-into-gear/) - [Transmission overheating](https://a1transmissionrenonv.com/symptoms/overheating/) - [Shudder or vibration (torque converter)](https://a1transmissionrenonv.com/symptoms/shudder/) - [Limp mode / stuck in one gear](https://a1transmissionrenonv.com/symptoms/limp-mode/) - [Transmission symptoms](https://a1transmissionrenonv.com/symptoms/) Answers ## 4WD noise or 4WD not engaging (transfer case) questions Still have a question? Call [(775) 829-1333](tel:+17758291333) during shop hours. More answers are on the [questions page](https://a1transmissionrenonv.com/faq/). ### Why won't my 4WD engage? Common reasons are a shift motor or switch fault, low fluid, or a worn fork or chain. The flashing light on the switch is a good clue. ### Can I drive with a bad transfer case? In 2WD, short trips may be fine; a grinding noise or a case that binds is a reason to stop. Call the shop and describe it. ### How often should transfer case fluid be changed? Follow the maker's schedule in the owner's manual. The shop can look at it when the vehicle comes in. ### Is it the transfer case or the front axle? Noises and failures to engage can come from either. A lift inspection and a road test tell them apart. ## 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)