1999 Geo Tracker Vibration

I have a 2.0 litre Tracker that has a very pronounced vibration at idle and becomes worse when put in reverse. When driving, vibration lessons but is still there. The rear main seal has just started leaking heavily but the vibration has been there for a long time. There is no engine noise such as bearing or lifters but the rear main leaking is new and it's leaking heavily.
This is what we done so far:
-unbolted torque converter and started engine (no change)
-checked all engine and trans mounts (all good)
-checked harmonic balancer (visually looks good)
-had major tune-up (no change)

I could use any suggestions!! My wife won't even drive it now because it scares her.

Ron

im not too sure but i would like to believe that your transmission might be going out, did u change the tranny fluid? if u did was there tons of shavings? or was there metal shinny looking marks on the inside of the tranny pan? or even maybe the filter is clogged or low tranny fluid?

Some of these engines have internal crank balancers, and when they have a problem it is a very rough ride - mostly at idle and lower speed. If this one has a GM engine you will want to follow this up - it might have to do with the rear main leak. Since you took the converter out and ran the engine with no change, I presume it is an engine problem. Otherwise maybe a dying cylinder, weak plug, or wire. A bad plug, wire, or cap can cause a huge amount of vibration in a 4 cyl engine - but with a tracker you really notice the lost power at higher ranges.