Bad Grinding Noise When in 4WD High Range
Welcome to the club! RELAX – there is nothing wrong with your transfer case. Anyone with a lifted Samurai and a conventional front driveline will experience this. The more it is lifted the worse it is. Here is the reason. In order for a driveshaft to operate correctly the driving shaft, being the t-case – and the driven shaft, being the pinion – need to be on parallel lines. Not point at, but parallel. This causes the vibration from the operation of the top ujoint to be cancelled by the equal and opposite operation of the bottom ujoint. The t-case in the Samurai is tipped down in the back 7 degrees. This is to allow the primary use driveline to operate correctly. But since the front is tipped up 7 degrees and the pinion is up 9 degrees, this makes the front driveline exactly opposite of correct. Both joints vibrate and cannot cancel each other. The vibration transfers into the backlash of the gearing & axles – all the way to the hubs, which is why it is loudest in the float between power and compression. No tipping up of the pinion will fix this, don’t try it. It will only wack out the castor angle or steering. High speed 4WD isn’t needed that often. So most people just live with the noise and vibes. Otherwise a C/V front driveline can help a lot but not completely – depending on the amount of actual lift. This is a commonly asked question during the winter months – you might forward this to your favorite boards.