had a leaking shaft seal on my right side transaxle on an exmark phazer. pulled it out, lost all oil, replaced seal put back in. pulled check plug, filled with 20-50 full synthetic mobil 1, and did the purge procedure, wont move. i have been letting it run, jacked up with the handles forward for 3 hours now. it will kick the tire if i pull the trans release then engage it back. but wont stay moving. what could be wrong?