6C-3XU Universal Joint Combo 1550x6C HWD / OSR Heavy Duty Conversion U-joint 1550 Series to Mechanics 6BL HWD

The 6c-3x is a 1550X6C series -- commercial fleet Class 5-6 trucks combination (OSR + ISR) snap ring retention universal joint measuring 1.375"/1.688" dual cap | 4.969"/5.531" dual width. This is a combination u-joint -- it bridges two different series in one cross. The 6c-3x is greaseable with zerk fitting. Every 6c-3x is verified for cap diameter, bearing width, and snap ring groove dimensions before it ships from Universal Driveshafts.

6C-3X -- 1550X6C Series Cap & Width Specifications

The this component specs: 1.375"/1.688" dual cap | 4.969"/5.531" dual width. Cap diameter determines which yoke bore it fits -- the cap must seat fully into the yoke without play. Dual cap diameters (1.375" and 1.688") bridge two different series yokes in a single cross. Bearing width (4.969" and 5.531" across the body) controls the span between yoke ears. A cross that is too wide won't fit; too narrow and the snap rings don't seat in the groove. MECH- 6CX1550.

Confirm both ends of the driveshaft before installing the this u-joint. Combination u-joints require matching the correct series at each end -- the 1.375" caps go into one yoke, the 1.688" caps go into the other. Getting the orientation wrong means the driveshaft won't balance and the it will fail early. Measure both yoke bores with calipers before ordering -- don't rely on the vehicle spec alone.

Installation Notes for this unit

Before installing the the assembly, clean the yoke bores of any rust, burrs, or old bearing material. The bearing cups must drop in by hand -- never drive them in with a hammer directly on the cup. Use a proper cross-and-bearing installation tool or a press. Driving a cup in at an angle cocks the needle bearings and destroys the this u-joint before it ever sees load.

After installation, verify full rotation without binding. A binding cross indicates a cup is cocked or seated too deep. The it should articulate freely through the full operating angle of your driveshaft before the vehicle is lowered off the lift.

Key Features

• Series: 1550X6C series -- commercial fleet Class 5-6 trucks
• Cap dia: 1.375" x 1.688" -- must match yoke bore exactly
• Width: 4.969" x 5.531" -- controls yoke ear span
• Style: combination (OSR + ISR) snap ring retention -- verify yoke groove type before ordering
• Greaseable -- zerk fitting included, service at regular intervals
• This is a combination u-joint -- it bridges two different series in one cross.
• Part number: the partU
• Brand: UDS
• Note: MECH- 6CX1550

Specifications

• SKU: this componentU
• Part Number: this u-jointU
• Brand: UDS
• Series: 1550X6C
• Cap Dia 1: 1.375"
• Cap Dia 2: 1.688"
• Width 1: 4.969"
• Width 2: 5.531"
• Snap Ring Style: COMBO
• Lube: Yes -- grease fitting
• Notes: MECH- 6CX1550