Still not exactly sure, removed the e-brakes and now there are no clunks or squeels, all there is now is the slight vibration and somewhat of a slight humming noise that is deffinately orbital. It has to be coming from the rear diff since it began right after they tightened the pinion nut and put a new seal in. Its just really weird that no noise could be heard under a stehascope when it was on the lift....Im gonna add some friction modifier and put some miles on it and see if that helps out. I have to take a trip to Michigan this weekend so hopefully I dont throw a tooth in while on the road.

 

Well turns out that it isnt my rear diff....I did some troubleshooting after reading many many posts and it appears to be my vacuum control solenoid, the one on the firewall that engages or disengages the front hubs...Its a releif to me that all I have to change out is the solenoid instead of worrying about a new rear end. As soon as I engage 4 high the sound goes away, i just never noticed it in 4 high because the only time I engage it is on the beach.

Thanks everybody for all the help and suggestions, this site has been immensely helpful