Stopped by my dealer to ask some questions, and tech happened to look up my tractor and found this "Mandatory Campaign" for the L --60 series tractors that was issued in December after my tractor had been delivered. It is for a "Closed Crankcase Vent" problem, where, at temperatures below 0, a part might accumulate water and freeze shut. Damage to engine could result. A kit has to be installed. It involves serial numbers 30000 through 40700 approximately. Your dealer should contact you, but it never hurts to be proactive.