Cylinder Hones for U-Joint Surface Finishing

Universal joints or U-joints are drivetrain components that handle flex and torque while helping to convey power from a car or truck’s engine to its wheels. These cross-shaped couplings have four “legs”, each of which terminates in a needle-bearing cup. One set of cups mounts to the driveshaft, allowing it to flex under load. The other set of cups mates to the transmission or the rear differential, and attaches with yokes and U-bolts.

Routine maintenance can extend U-joint life, but universal couplings wear over time and can fail. Signs of a bad U-joint include squeaking or clunking noises, and excessive vibration. Although some car and truck owners prefer to take their vehicles to a professional automotive technician, do-it-yourself (DIY) mechanics can replace U-joints, too.

Bad U-Joints and Deformed Yokes

For a do-it-yourselfer named ENafzinger, replacing the U-joints on a Dodge RAM 3500 Big Rig was the most challenging part of a DIY project that included installing upper and lower ball joints, a free spin hub conversion kit, and manual hubs. As the Dodge mechanic explained to Turbo Diesel Register (TDR), an on-line automotive forum, “it took a 25-ton hydraulic press” to remove one of the U-joints on his truck.

Most U-joints aren’t that hard to remove, however, and it’s cheaper to change them than to buy new axles just so that you don’t have to struggle with rust. Although removing the U-joints deformed the yokes, ENafzinger used hand tools to correct the shape of the holes. The truck mechanic then used what he called a “cylinder dingle ball hone” to “clean up the U-joint bores”. 

How to Surface Finish U-Joint Bores

Cylinder hones from Brush Research Manufacturing (BRM) have their share of nicknames, including ball hones and dingleberry hones, but we prefer our Flex-Hone® tradename. A resilient, flexible honing tool with a soft cutting action, the BRM Flex-Hone® features distinctive-looking abrasive globules that are permanently laminated to flexible nylon filaments.

Flex-Hone® tools are known for more than just their abrasive “balls” or “dingleberries”, however. Self-centering, self-aligning to the bore, and self-compensating for wear, these cylinder honing tools mount in handheld electric drills and are easy-to-use. Rigid, elaborate setups aren’t required, and flexible hones impart a plateau finish that optimizes lubrication.

Cylinder Hones for Automotive Projects

Ball hones are always specified in an oversized condition (larger than the bore) and are available for any size or type of cylinder. Standard BRM cylinder hones range in diameter from 4mm to 36”, and come in 8 abrasive types and 11 grit selections. The Flex-Hone® Resource Guide, a free downloadable technical book from Brush Research, provides detailed information on topics such as tool selection and recommended RPMs.

BRM cylinder hones are trusted by auto parts manufacturers, engine rebuilders, diesel mechanics, car and kart racers, and automotive restoration specialists. In addition to surface finishing U-joint bores, a task that ENafzinger mastered in Dodge RAM project, automotive applications for Flex-Hone® tools include engine block honing, brake rotor finishing, cylinder wall deglazing, and cross-hole deburring.