5-86-68S UDS 1610 Threaded Rubber Dust Cap for 2.000×16

5-86-68S UDS 1610 Series Threaded Rubber Dust Cap — 2.000x16 Spline

The 5-86-68S is a UDS threaded rubber dust cap for 1610 series slip yoke applications with a 2.000x16 spline stop shaft — 2.000-inch diameter, 16 splines. This screw-on cap seals the open end of the slip yoke's spline bore cavity, blocking water, road salt, and debris from contacting the stop shaft splines and yoke internal splines. The 1610 series is used in medium-to-heavy truck driveshaft applications and represents a significant torque step above the 1480 series — U-joint cap diameter increases to 1.875 inches at 1610 series, the same cap diameter as the 1810 series but with a narrower width.

The 2.000x16 stop shaft dimension governs fitment for 5-86-68S. The bore into which this cap threads is machined to fit a 2.000-inch shaft, with 16-spline geometry on the stop shaft itself. A 2.500x16 cap (1710 series) is physically too large to thread into a 2.000-inch bore. A 1.375x16 cap (1410 series) will be loose. Verify with a caliper: measure the stop shaft at the spline major diameter and count the splines directly. Threaded rubber cap retention allows hand-tight installation and hand removal, which simplifies spline inspection during preventive maintenance on 1610 series commercial driveshafts.

Specifications

• Part Number: 5-86-68S
• Brand: UDS
• Series: 1610
• Spline Spec: 2.000" diameter x 16 splines
• Type: Threaded Rubber Dust Cap
• Retention: Screw-on (threaded)

Fitment & Installation Notes

Confirm stop shaft diameter is 2.000 inches and spline count is 16 before ordering 5-86-68S. Inspect the yoke bore opening for threaded engagement features — a smooth bore indicates a press-on cap application, which is incompatible with the threaded 5-86-68S. Replace at any sign of rubber degradation; a missing dust cap on a 1610 series yoke in wet or off-road service will allow corrosion to progress within a single season.

The 1610 series occupies a torque tier between 1480 and 1710 in Spicer's capacity hierarchy. Stop shaft corrosion from a failed dust cap progresses faster in 1610 series applications than in lighter-duty series because the larger spline profile creates more surface area for corrosion products to accumulate and lock the splines together. A seized slip yoke that cannot telescope will transfer suspension travel forces directly into the driveshaft tube as a bending load, which is a failure mode entirely preventable through proper dust cap maintenance.

Thread 5-86-68S on by hand until seated against the yoke bore lip. Over-torquing tears the rubber at the thread root. Verify the cap face is parallel to the yoke bore opening and the cap does not contact the stop shaft during installation.

Explore related slip yoke components including 1610 series slip yokes and U-joints for complete driveshaft service.