Okay I know that many Jeepers have the 3500 Tranny in there Jeeps just curious if you have any of these problems??

My 2001 recently started to feel really weird. It is the hardest thing to decribe but I will try. I have the NV3500 5 speed tranny and there was a lot of vibration coming threw then shift lever. Then I just notced today that when in 3rd or 5th gear there seems to be alot of play side to side almost like it is in Neutral?

Shift fork or the nylon ball??? What else should I be looking for/at???