Suppliers * William Mayo has been named general manager of Caterpillar's Truck Engine Div., replacing James Parker, who has been promoted to director of the company's electric power generation group.
* Allison Transmission has appointed James L. Wanaselja director of North American Sales; Jim Coleman is named director of global market development.
* Navistar International Transportation Corp. has appointed Steve Koch vp-sales and distribution for the company's truck business and Wayne Krzysiak vp and general manager of its Parts Business Center.
* Steven Lewis has been appointed vp and general manager of Kysor Europe - HVAC by the Schwitzer Group.
* Modine Manufacturing Co. has appointed Ernest Thomas group vp-highway products.
* Landstar Logistics has appointed Kay R. Dykes director of business development.
* Robert J. Merkov has been named district sales manager for fifth wheel products at American Steel Foundries.
* Trevor Hoskins, senior vp-public affairs, will retire from Bridgestone/Firestone at the end of September.
* Lee McCleery becomes national accounts manager for Eaton VORAD Technologies.
* Gamber-Johnson has named Jeff Greene to the position of general manager.
* Lang Mekra North America has appointed Steve Traylor national sales manager.
Fleets * John Ruan III has been appointed chairman and CEO of Ruan Transportation Management Systems.
* KLLM Transport Services Inc. appointed William J. Liles III, formerly vp-sales & marketing, president and CEO.
* Michael S. Walters has been named president and CEO of Arnold Transportation Services Inc.
* Robert G. Petrancosta has been named director of safety and environmental compliance for Con-Way Transportation Services.
* Thomas Paulsen has been named to the new position of senior vp-operations at Consolidated Freightways.
* Scott F. Miller, president of Miller Transportation, has been elected chairman of National Tank Truck Carriers.