Took my TJ off-road. Sometimes transmission sounds like it's chewing rocks


Apr 16, 2019
Austin, TX
Today I took my 4-cylinder, 5-speed TJ to an off-road trail in Colorado. Everything was going well for a while, and then it happened. Going downhill in first gear there came this ugly noise from underneath, as if the gearbox were chewing rocks. Then I came to a complete stop and the noise persisted for a few more seconds and then went away. That happened several times. When I got back on the pavement, no problems. Based on my description, do y’all have any inkling what the problem could be? This happened in 2H, 4H, and 4L. Thanks.
Is it possible your transfer case was not fully engaging?
I’m not sure. The thing that makes me think the problem is in the gearbox is that a couple of times, after the rattling started, I came to a full stop with the clutch pressed and the rattling continued for several seconds. When you are stopped, nothing is moving in the transfer case, I don’t think.