There is a similar thread, but I feel the "thumping" underneith me when going over bumps, coasting (especially around a turn), in reverse, and especially in 4x4. Now...If I'm in 4x4, it is accelerated if coasting, but under heavier acceleration, it is much less noticable. In another forum, the throughts were either the front driveshaft slipyoke or tranny mount. Thoughts?