Between $48 to $70
GM has a new Auto Trak II Transfer Case Fluid (GM Part No. 12378508), which has a bluish color to it. The newer fluid has better friction modifiers. While your doing the job, it s a good idea to change the drain and fill plugs (GM Part No. 15032997) out too. lbs., and refill the transfer case with fluid until the fluid level is even with the bottom of the fill hole. Basically, fill it up until the fluid runs out the fill hole. It takes almost 2 quarts to fill it up. To make the fill up easier, you may want to purchase a pump at a local auto parts store. Our recommendation: Transfer case fluid should be replaced at least every 30,000 miles. You should schedule this maintenance for your vehicle, and anytime the transfer case is inspected, the transfer case fluid should be checked. In all-wheel-drive vehicles, the transfer case helps to shift power from one axle to another, depending upon traction conditions. Lubricant fluid in the transfer case helps to keep its gears cool and turning smoothly. Parts: $8 - $18. The average cost for a transfer case fluid replacement is between $48 to $70. Labor costs are estimated between $40 to $52 while parts are priced between $8 to $18. Get a personalized estimate based on your location and specific car. Estimate does not include taxes and fees. Transfer cases can use many different types of fluids so it's very important to use the exact type specified by the manufacturer. Over time, transfer case fluid breaks down and becomes contaminated with moisture, which can lead to damage from a lack of proper lubrication. Locate the oil fill plug on the transfer case. 3. Remove the top oil fill plug. 4. Using a flashlight, check for oil at the fill plug hole. When full, the oil should be just below the top hole. 5. With the top oil fill plug still out, remove the bottom oil drain plug to drain the oil into an oil drain pan. 6. Inspect transfer case oil for metal flakes when in the oil drain pan. 7. Thread the oil drain plug back into the transfer case (lower plug hole) and torque to manufacturer's specifications.  Posted. Thinking about changing the fluid in the transfer case and differentials on my 04 Tahoe Z71. The transfer case is the NP8 unit. I called the local dealer to get a price on having the fluids changed to which the service writer replied We don't just change it, we flush the differentials and the transfer case. It's much better. It will run you $380.. Posted. Wondering if anyome has an approximate cost I should expect to pay to change the fluid and filter in the tranny, change the transfer case fluid and the front and rear differential fluids. It's a 2004 Trailblazer.  The transfer case is a special gear box found in four-wheel and all-wheel-drive vehicles. It sends drive power from the engine to the front and rear axles. In all-wheel-drive vehicles, the transfer case helps to shift power from one axle to another, depending upon traction conditions. Lubricant fluid in the transfer case helps to keep its gears cool and turning smoothly. Replacing this fluid at appropriate intervals can help prevent premature wear and damage caused by contaminated or broken-down lubricant
http://www.gm-trucks.com/forums/topic/23946-changing-transfer-case-fluid-guide/ https://www.yourmechanic.com/services/transfer-case-fluid-replacement http://repairpal.com/estimator/transfer-case-fluid-replacement-cost https://www.automd.com/48/how-to-check-and-replace-transfer-case-fluid/ http://www.gm-trucks.com/forums/topic/87847-transfer-case-and-differntial-fluid-flush-or-change/ http://www.stripersonline.com/surftalk/topic/447433-approximate-cost-for-transtransfer-casedifferential-fluid-changes/ https://www.yourmechanic.com/services/transfer-case-fluid-replacement
transfer case fluid change cost