I have a 98 4runner that has 139k on the engine. I've developed a viberation that is very slight until you get to 60 mph and then you for sure know it's there, when you hit 70 it smooths out but can still feel it . I took it to my mech. today and he thought it was my engine because as we were driving down the road at 65 he told me to put the clutch in and it stopped so he said it wasn't my drive train. Anyone got any ideas??Thanks Jeff