Caterpillar Operators Manual | Format: Enhanced Reproduction (Written by Manufacturer) | Pages: 54 | Fits: D3 Crawler (SN# 6N1 | 79U1 and Up | 82U1 and Up | 83U1 and Up) Content: Critical every day use and preventative maintenance information for your Caterpillar Crawler (CT-O-D3 (6N1)). In general, Operators Manuals usually contain lubrication, capacities, minor adjustment procedures, and other important usage information. Every Caterpillar owner should have the operators manual.