I have a 4WD MX5100 with about 110 hours. Recently I noticed that the front tires have no power to them even though the 2WD/4WD selector is in the 4WD position. The lever will not move from the 4WD position. Does anyone have advice on how to get the selector lever to move? I am hoping that by moving to 2WD and then back to 4WD the problem will be corrected. Thanks in advance for any help offered