DRIVESHAFTS AND UNIVERSAL JOINTS

CONSTRUCTION u SEAMLESS STEEL TUBING u U-JOINTS AND YOKES u ONE OR TWO PIECE u EXTENSION OF TRANSMISSION OUTPUT SHAFT u HAS NATURAL VIBRATION TENDENCY

TYPES OF DRIVESHAFTS u HOTCHKISS DESIGN – EXTERNAL SHAFT AND U-JOINTS – USED WITH LEAF OR COIL SPRINGS – ONE OR TWO PIECE u TORQUE TUBE (REAR MOUNTED TRANSAXLE) – RIGIDLY CONNECTED AT BOTH ENDS u FLEXIBLE TUBE

DRIVESHAFT VIBRATION u CAUSED BY: (BY DESIGN) – TOO LONG OF A SHAFT – TOO SMALL DIAMETER – TOO MUCH DRIVESHAFT ANGLE u CRITICAL SPEED - SPEED WHEN IT REACHES NATURAL FREQUENCY

DRIVESHAFT IMBALANCE CONTINUED u TO CORRECT IMBALANCE – BALANCE WEIGHTS – CARDBOARD LINERS – RUBBER INSERTS (HELP NOISE TOO) – TUBE IN TUBE WITH RUBBER INSERTS – LINEAR STIFFNESS – FIBER COMPOSITE

INSPECTION OF DRIVESHAFTS u DENTED u BENT u UNDERCOATING u BALANCE PADS FALLEN OFF u BROKEN TRANS OR ENGINE MOUNTS

U- JOINTS u TYPES OF UNIVERSAL JOINTS – SINGLE CARDAN JOINT – DOUBLE CARDAN UNIVERSAL JOINT – CONSTANT VELOCITY JOINTS – SLIP JOINTS

U-JOINTS PARTS u CROSS (SPIDER) u FOUR MACHINED TUNNIONS u NEEDLE BEARINGS u DRIVEN AND DRIVING YOKES u SNAP RINGS INSIDE OR OUTSIDE u CAPS u U-BOLTS OR STRAPS

U-JOINT FACTORS u ALLOWS ANGLE VARIATION OF DRIVESHAFTS u SLIP JOINTS ALLOWS LENGTH VARIATION u SPEED VARIATION OF JOINT IS A FACTOR OF DESIGN

SPEED VARIATION u NATURAL TENDENCY TO SPEED UP AND SLOW DOWN TWICE DURING ONE REVOLUTION u SPEED VARIATIONS MAY BE FELT AS TORSIONAL VIBRATIONS u THE MORE THE ANGLE, THE MORE THE VELOCITY WILL CHANGE EACH REVOLUTION OF THE SHAFT

PHASING OF U-JOINTS u TORSIONAL VIBRATIONS ARE TRANSFERRED DOWN THE SHAFT TO THE NEXT U-JOINT u TO CANCEL THIS VIBRATION, THE SHAFT SHOULD HAVE TWO JOINTS AND EQUAL AND SLIGHT ANGLES TO EACH OTHER

CANCELING ANGLES

U-JOINT SERVICE u MUST KNOW U-JOINT SIZE – OUTSIDE YOKE SPAN – INSIDE YOKE SPAN