Methodology for determining the causes of vibration of the transfer case and the floor of the body

First of all, note at what speed the vibration of the transfer case occurs, then proceed to determine the causes of vibration.

Challenge #1

Set the transfer case and transmission levers to neutral position and start the engine. Set the engine speed to the speed of the vehicle at which the vibration occurred.

If the vibration persists while the vehicle is stationary, the fastening and condition of the engine mounts should be checked, as they are the cause of vibration.

Test #2

If vibration is not detected during test No. 1, then place the transfer case levers in the neutral position, start the engine, engage the gearbox in direct gear and set the engine speed to the speed of the vehicle at which the transfer case vibration occurred.

If vibration is observed on a stationary car, at such a crankshaft speed, then its cause is a malfunction of the intermediate carlane shaft (imbalance, bending of the fastening bolts or flexible coupling flange, jamming in the cardan joint).

Challenge #3

If no vibration is found during tests #1 and #2, proceed to test #3. Accelerate the vehicle to a speed where vibration occurs and place the transfer case and transmission levers in neutral. If the vibration persists, then it is caused by a malfunction of the front or rear driveshafts (imbalance, jamming of cardan joints) or an imbalance of the inter-axle differential.