95 Dakota SLT Club cab. 4x4 V6

Hey. I noticed the past few times I drove my truck a very tiny bit of slippage, kinda felt like transmission slippage but it was so suttle I wasn't sure I didn't imagine it. But today it got a little more jerky. There's defintely some slippage.

I know my transfer case needs some work - I can engage 4x4 when necessary but it makes a really clicking/grinding noise when moving. I dont like doing this so i have only used it a few times to get up snowy driveways and stuff. To my knowledge the Transfer case needing repair should not effect two wheel drive movement.... correct me if wrong.

Also, I noticed about half of rear axle(the part with the gears inside)is covered in grease. I may possibly have a leak, but have noticed no puddles, just the grease. So I might need to geta gasket and refill that...

With these facts; do you think I need tranny work (please say no lol)? Or just some rear axle maintenance. Or transfer case work? Throw out your suggestions.

Thanks a lot