A quarry operation reported that a Volvo L110H wheel loader had developed noticeable lateral play in the articulation joint - the central hinge that allows the machine's front frame to pivot relative to the rear frame for steering. The operator reported a "wobbling" sensation during travel and a "knock" sound when changing steering direction under load. Additionally, the machine's front tires were showing accelerated wear on their inner shoulders, suggesting a misalignment or articulation-play-induced tracking fault.
The technician first understood the L110H's articulation architecture. Volvo's wheel loaders use a heavy-duty center-pivot articulation joint comprising two large-diameter hinge pins - one upper, one lower - mounted to spherical plain bearings and bushings housed in the front frame's articulation towers. The joint is designed to accommodate both articulation (steering) and oscillation (front-frame rocking on uneven terrain). When the hinge pins and bushings wear, the joint develops lateral play, allowing the front frame to shift laterally relative to the rear frame before the steering cylinders can fully control the motion - producing the wobble the operator reported.
He began diagnosis by parking the machine on a flat, level surface with the front wheels pointed straight ahead, then used a long pry bar to check for lateral play in the articulation joint. Inserting the bar between the front and rear frame at the lower hinge-pin location, he applied firm lateral pressure - the front frame shifted visibly by approximately 6 millimeters relative to the rear frame (spec maximum is 2 millimeters). He repeated the test at the upper hinge pin and found 4 millimeters of play. Both hinge pin assemblies were beyond service limits.
He then inspected the articulation joint's lubrication system. The L110H uses centralized lubrication lines that feed grease to the hinge-pin bushings from a central manifold. Upon tracing the lines, he found a split grease hose at the lower hinge pin - the lower bushing had not received grease for an extended period, explaining the asymmetric wear (more play at the lower pin than the upper). Grease starvation had allowed the hardened steel pin to operate in boundary contact with the bushing, progressively wearing both surfaces and creating the lateral play.
The repair involved replacing both upper and lower hinge pins with new hardened units, replacing all four bushings with new induction-hardened bushings, and repairing the split grease hose. The technician also inspected the articulation joint's oscillation bearings (which accommodate front-frame rocking) and found them serviceable. After reassembly and proper greasing until fresh grease purged from each bushing, the articulation play was re-measured - the lateral play was reduced to under 1 millimeter. The steering wobble and knocking sound disappeared, and the front tire wear pattern normalized as the front frame maintained proper alignment with the rear frame under load.
