s h o p t a l k

‘Maintenance Free’ Drivelines Do Need Grease

‘No’ doesn’t mean ‘nothing’ when we’re talking about maintenance.

Grease gun in hand and creeper beneath his back, today’s shop technician may wonder where all these “maintenance free” truck components are. He knows that term is a misnomer.
     A lot of pieces need less attention than they used to, but they eventually need that proverbial, if not actual, shot of grease. Take drivelines: Exposed as they are, the driveshaft and its parts get more than their share of splash and grime from the road. They are made to take it, but U-joints must be periodically lubricated with proper grease to smooth the constant movement among their parts.
     Greasing is done at intervals recommended by suppliers, and usually part of a truck or tractor’s “A” or “B” preventive maintenance check. Typically this has been 15,000 miles. Complex seals and other refinements on modern products help retain and distribute the grease once it’s pumped in.
     Engineering progress has extended the intervals between required lubrication service or eliminated servicing altogether. “Spicer Life” and Rockwell “Permalube” and “X-tra Life” are the names of these products; all use advanced engineering, especially in seals, lube passages, bearings and advanced materials, and highly precise manufacturing techniques, along with advanced greases, to achieve lower maintenance.
     Things to determine in these products is the actual life of their U-joints and other parts, as well as required lube intervals. And remember that “low maintenance” is not the same as “no maintenance.” If it needs grease every 100,000 miles instead of every 15,000, it still needs grease (and of the correct type) and must not be forgotten.
     This is not to discount the benefits of extended intervals. If a truck doesn’t have to come in for U-joint lubing every 15,000 miles, it can stay out on the road earning money — assuming the engine can go longer than 15,000 miles between drain intervals (they can, with a proper plan). Even if the truck’s on the premises regularly, time saved in maintenance adds up for the fleet and gives the owner-driver more time for his life away from the road.
     Lack of lubrication can cause vibration and premature wear of bearings and cross trunions in U-joints, as well as wear and galling of slip splines. Extreme cases of “dry” running can lead to breakage — a nasty fate for a components as beautiful in their basic simplicity (Leonardo da Vinci, the 15th century artist and engineer, envisioned the U-joint in his sketch of a helicopter-like flying machine).