NV246: Understanding the Tricks
The New Venture 246 transfer case has been around since the 1998 model year. Found in GM K trucks (Tahoe, pickup, Yukon, Suburban, Suburban EXT, Escalade and Avalanche), this is a large, heavy-duty transfer case.
A Guide to the NV 246 Transfer Case
This transfer case is one of the so-called “automatic transfer cases,” or “active transfer cases.” This description results from the fact that the 246 has an “automatic 4WD function,” a 2WD position, a 4WD High function, neutral and 4WD Low position. Driving the vehicle in 2WD has all torque flowing through the transfer case to the rear driveshaft, and the vehicle operates just like a 2WD vehicle.
Where the Rubber Meets the Road
About 75% of the technical calls we handle are dealing with transfer-case problems, usually occurring after a transfer case has been disassembled and repaired, or another reman or new unit installed. The conversations range from, “I took the transfer case apart and can’t find anything wrong with it” to “This is the third transfer case we put in the vehicle and I still have the problem,” or “The reman transfer case I just bought from you is doing the same thing.”
Making Money with Transmissions and Transfer Cases
At least 50% of the calls on the tech line are generated by shops that are not fully educated in the work they are doing or have not learned to look at the whole vehicle. The modern automobile is a combination of very complex interconnected systems that must function together correctly. Do not let the unit you are working on isolate your thought patterns from the whole vehicle. A knowledge of how these connected systems affect each other is a must for you to remain profitable.
A Transfer-Case Identity Crisis
So in your ever-expanding list of causes for stacked upshifts in computer-controlled transmissions, even if it is a two-wheel-drive vehicle, investigate the possibility of a four-wheel-drive-low command being the culprit otherwise known as a transfer-case identity crisis.
Dodge Ram Dilemma
A four-wheel-drive 1995 Dodge R1500 pickup was towed to a transmission shop, which performed the usual pre-checks, including checking codes, cooler flow, pressure, and function of the transfer case and both differentials. All preliminary checks pointed to the transmission as the problem, and its subsequent removal and inspection did verify a defective transmission. The transmission rebuild seemed to go routinely, and the transmission performed adequately on the road test.
