How to Balance Tractor U Joints

Tractors use two-piece drive shafts. Each piece uses two u-joints. The u joints must be kept in balance. This is also known as time or phase. These terms all refer to keeping the u joints and the yokes they are installed in in alignment. Improper balance will cause the drive shaft to vibrate when the tractor is in motion and can cause damage to driveline components. The situation is easily remedied by properly aligning the drive shafts.

Instructions

1

Park the tractor on a firm, level surface and set the parking brake. Place the transmission in neutral so you can rotate the output yoke on the transmission. There should be plenty of room for you to work under the tractor without using a jack and jack stands.

2

Use a wrench to remove the four bolts from the yoke flange that holds the rear u joint where it attaches to the pinion gear flange. Separate the flanges. Pull the rear drive-shaft section from the slip yoke at the center support bearing. This will separate the two drive-shaft halves.

3

Reinsert the rear drive shaft into the into the slip yoke so the yokes on the drive shafts that hold two opposing u-joint caps are in line with each other. They must be perfectly aligned. Put another way, the ends of the drive shafts that hold the u joints must line up.

4

Mate the drive shaft flange to the pinion flange. You will probably have to rotate the drive shafts to do this. Install the four flange bolts and tighten with a wrench.