Greasy Spiders

Greasing U-joint “spiders” must surely be the most entry-level of auto service tasks. Who didn’t start their careers at the lube rack? It’s a simple service procedure, but one that’s often underperfomed or just plain botched. What’s the right way to do the job? Service can begin with the customer. Ask about noise and vibration, and especially the ominous “clunk” when shifting into drive or reverse. If the vehicle is an off-roader, water or mud immersion is an obvious question. Mud boggers frequently use pressure washers on their machines, so the potential to drive dirt and water into joints is there with even a spotless chassis. Lift kits and oversize tire/wheel combinations add joint-killing angularity to any driveline, suggesting the need for more frequent inspections. On the hoist, the often forgotten first step is simple: examine the joint. Clean off mud, dirt and old grease with a rag and test the joint for play in both the axial (rotating) and side to side direction. If the joint needs replacement, there’s no point greasing it, right? When adding grease, it’s important to make sure that all four needle bearings ooze a little grease. If one or more don’t, then at least disassembly and probably replacement is indicated. And if the vehicle sees heavy-duty use…and most rear-wheel-drive vehicles these days are trucks and SUV’s…consider heavy-duty replacement parts. Features to look for include plugs fitted to the caps rather than the core of the spider casting. If you do grease through the spider, remember to fit replacements so that the nipple is compressed during normal driveshaft rotation. This will prevent the nipple’s threaded opening from becoming a possible crack starter in severe service.