As of 2014 [update] , each Wolverine operates with two General Electric Genesis P42DC locomotives, 3-5 Horizon coaches, and an Amfleet cafe/business class car. In the winter, Superliners are sometimes used. The equipment pool for the Wolverines comprises 14 Horizon coaches and Amfleet cafe/business class cars (one is shared with the Blue Water ), split across three consists . The locomotives usually operate in a push-pull configuration, however sometimes both will be at the head end. Due to the FRA requirement of positive train control for operations above 79 mph, locomotives on the Wolverine are required to have Positive Train Control, supplied by Amtrak's Incremental Train Control System. Because of this modification the units are usually captive to the Michigan services.
The wing spar of the Model 18 was fabricated by welding an assembly of tubular steel. The configuration of the tubes in combination with drilled holes from aftermarket STC modifications on some of these aircraft have allowed the spar to become susceptible to corrosion and cracking while in service.  This prompted the FAA to issue an Airworthiness Directive in 1975, mandating the fitting of a spar strap to some Model 18s. This led, in turn, to the retirement of a large number of STC-modified Model 18s when owners determined the aircraft were worth less than the cost of the modifications. The corrosion on unmodified spars was not a problem, and occurred due to the additional exposed surface area created through the STC hole-drilling process. Further requirements have been mandated by the FAA and other national airworthiness authorities, including regular removal of the spar strap to allow the strap to be checked for cracks and corrosion and the spar to be X-rayed . In Australia, the airworthiness authority has placed a life limit on the airframe, beyond which aircraft are not allowed to fly.