I searched and did not see anything on this exact problem.

On my 1997 F-150 (108K) there is a series (usually 2-3) clunks that I can lightly feel in the drivers side floor. They happen consistently and seem to happen as the engine winds up. If I step on the brakes and then the gas the clunks happen even though the truck is not moving. They are not felt or heard while driving. I have checked all tie-rod ends, linkages etc, all tight and the truck drives fine, no pulling etc. Could this be an engine or tranny mount? Any thoughts?

Thanks!

 

Could be universals, Had the same problem and couldn't tell till i removed the drive shaft and replaced the universals, they were football shaped but when installed the shaft was tight and coudn't tell. I carried it to a shop and they told me it was my rear end bearings, while i was changing them I went ahead and chaged the universals while I had the shaft out, and by the way there was nothing wrong with the rear bearings either.