As a heavy duty mechanic, I worked on 992A & B 25K models, with features like hydraulic control valves for the boom and bucket contained, submerged, in an oil tank located above the front axle. Troubleshooting problems like boom or bucket drift was a nightmare. The 992C, a 49Z serial number, eliminated all those problems, bucket level and boom height kickout were "electronic" rather than hydraulic thru the pilot system, another great improvement. The 992A&B used an expensive D348 engine.
