13.2. Definition of the reasons of vibration and centering of the transfer case

We remember the speed of the car and turns of the engine at which there is a vibration in a zone of fastening of the transfer case.

On the standing car we transfer levers of the transmission and the transfer case to neutral situation and we start the engine. We determine the speed of a bent shaft corresponding to the car speed at which there were vibrations. If vibration remains, we check a state and fastening of support of the power unit.

If vibrations are not revealed, we repeat the previous test, having included direct transfer in the transmission. If this time vibration was shown, the intermediate shaft is faulty (fastening of flanges, jamming of the hinge, a crack of the elastic coupling, etc. weakened).

If there are no vibrations, accelerate the car slightly above noted speed and we transfer levers of the transmission and the transfer case to neutral situation. The vibration reasons in this case – an imbalance of interaxal differential, forward or back driveshafts, jamming of their hinges.

Also we check fastening of the transfer case to a body: a condition of rubber-metal support (gaps and peelings of rubber are inadmissible), an inhaling of nuts, lack of fatigue cracks on a body.

Before centering of the transfer case we check the condition of support of the power unit and correctness of their installation (aligning washers of pillows of the engine have to enter the corresponding openings of side arms). We install the transfer case on the car, without tightening until the end of a nut of fastening of arms of its suspension bracket. Moving the transfer case in the longitudinal, cross and vertical direction (tightening or weakening nuts of its fastening), we try to obtain the minimum and uniform gap between flanges of an intermediate shaft and the leading shaft of the transfer case (flanges have to be at one level and are parallel each other). The gap between a body floor and support is filled with adjusting laying and we combine the aligning corbels of flanges, having slightly shifted the transfer case forward (at a gap size between flanges). Finally we tighten nuts of fastening of support of the transfer case.