I skipped the phone interview since I was currently a intern at Caterpillar. My first portion was an on campus 1:1 interview that was to judge my interest level and basic communication skills. About a month and a half later I visited Peoria for a two day visit. The first night we were taken out to dinner with a new employee that had a similar job background. The next morning was a 4 and a half hour marathon of 1:1 interviews with employees of various management levels. The questions were all very similar and strictly behavioral. All responses needed to be in the STAR format (Situation, Task, Action, and Result) and were not very difficult. The interview was more of a endurance race rather than a sharp test. This was followed by a tour of one of the Peoria manufacturing facilities. The people were all very profession and very, very conservative. You get a feeling that the corporation is very bureaucratic. The benefit was excellent benefits (I was offered a pension and 401k matching) and a very stable company (long term, not counting current economic situation).