How to fix front wheels not engaging on 4x4 Yamaha Kodiak 400

Full time 4x4 is not spinning the front wheels anymore. Check this to see if it's a simple solution. This is on a 95 Kodiak 400. May also be the same on Yamaha Big Bear 350 (1989–1998) Yamaha Kodiak 400 (1993–1998) Yamaha Timberwolf 250 (1992–1993,) Yamaha Wolverine 350 (1995–2000) Amazon associate link to Hub: https://amzn.to/45ENz3k