I have a 2004 4WD Blazer which has leaked trans fluid into the transfer case via a bad seal. I drained out 2.5 quarts excess fluid from the transfer case. When I was under the vehicle I grabbed the rear driveshaft and to my somewhat surprise I was able to rotate it some. The u-joints seem tight and it appears the slop is within the transfer case. Could this be gears in the transfer case wearing? The vehicle has 200,000 miles on it but I have owned it for only the past 20,000 miles. I believe it is the original transfer case. I don't know how long the seal in the transfer case has been leaking trans fluid but could the excess fluid have caused damage to the transfer case?