I have a 89 jeep cherokee 4.0 auto. which is never in 4 wheel drive and checked the transfer case which has not been done for a couple 2-3 years and was really low Have I,ve done damage to the transfer internals or does the transfer case not really work until in 4 wheel drive. Is my first 4x4. If damage is done what are the signs or noises .

 

How low was it? If you can reach fluid through the fill hole it's usually OK.