Kubota BX1880, BX2380, BX2680 Front Axle Pivot Adjustment

BX1880 / BX2380 / BX2680 Owner Service Guide

The front axle swings on a center pivot pin so the front wheels can follow uneven ground. A slotted adjusting nut on the front end of the pivot pin sets how tightly the axle is held. As the bushings and thrust surfaces wear, the axle gets loose on the pin, and the front wheels shimmy and shake the steering wheel. Kubota calls for adjusting the pivot every 400 hours.

Interval	Every 400 hours
Time	15 minutes
Tools	Socket for the adjusting nut, torque wrench, pliers
Parts	New split pin

Warning. Stop the engine and remove the key before adjusting the front axle pivot. Park on firm, level ground and set the parking brake.

Adjusting the pivot

The adjusting nut is on the front of the front axle, at the center, below the front frame. If a front loader or front guard is installed, work from underneath.

Straighten the legs of the split pin and pull it out of the adjusting nut.
Tighten the adjusting nut to 15 ft-lbs.
Check that one of the slots in the nut lines up with the split pin hole in the pivot pin.
If no slot lines up, tighten the nut slightly until the next slot does. Do not back the nut off to line it up.
Install a new split pin and bend the legs apart around the nut.
Rock the front axle by hand. It should swing without binding and without clunking.

Front axle viewed from the front, showing the pivot adjusting nut and split pin — Front axle pivot adjusting nut (1) and split pin (2).

Do not tighten the nut beyond what is needed to line up the next slot. The axle must still swing freely on the pivot pin.

Rocking force check

The shop check for this adjustment measures the force needed to swing the axle with one front wheel removed, using a spring scale on the front gear case cover. The specification is 11.1 to 67.4 lbf. If the axle still shimmies after setting the nut to 15 ft-lbs, the pivot bushings may be worn and should be inspected.