Just noticed that I have tranny fluid leaking from my T-case at the front drive shaft, is this a problem (besides it leaking)? I'm going to get a new seal for it, but was wondering if I need to look a little deeper into this.

Also have question about shaft angles. I have a 4" lift and wondering what the angles should be for the drive shafts? I've had to replace the rear u-joints twice in the past 3 years. After installing lift, shaft did not go into T-case as far as before, do I need to lower the T-case?

 

Bad things can happen if the fluid level drops too low for too long. I would check for play in the front output shaft. If there's play, then the support bearings are likely toast. Bad bearings often cause a leak because they aren't holding the shaft in the center of the seal any longer.

As far as the lift & angles go, most suspension lifts change the pinion angle on the axles to improve driveshaft geometry. It may be necessary to drop the transfer case down (spacers between the bracket & the frame) to further improve the angles if you are having trouble with the life of the u-joints that are being properly maintained (greased regularly). If you are using cheap generic brand u-joints, then you may want to try another manufacturer to see if the life improves.