Copyright Goodheart-Willcox Co., Inc. Heavy Equipment Power Trains and Systems 590 Skid Steer Chain Drive Fill Levels Skid steer chains have their own oil sump. The side of the chain drive housing contains a fluid level plug. Methods for draining, checking, and filling the oil reservoir vary among manufacturers. Consult the manufac- turer’s service literature for specific instructions. Most commonly, fluid level is checked by removing the fill plug on the side of the chain drive housing. Be sure the skid steer is on level ground. The oil should be level with the bottom of the fill plug hole. See Figure 17-30. Caterpillar recommends checking the chain drive oil level every 500 hours or three months and replacing the oil every 1000 hours or six months. Skid Steer Chain Drive Housing Breather Skid steer chain drive housings have a breather that must be checked along with the chain drive fluid level. When the machine operates in wet climates, water accumulates in the chain drive housing if the breather becomes plugged. In severe cases, the water will freeze in cold weather, preventing the skid steer from driving. Tensioning Drive Chains Skid steer chain drives wear over time, causing the chain drive to loosen, make noise, and potentially fall off the sprockets. Severely loose chains can cause the sprockets to slip on the chain. Most skid steers have a provision for adjusting the drive chain tension. Case, New Holland, and Caterpillar skid steer axle housings have elongated holes. A technician can loosen the axle housing mounting bolts and move the axle housing forward or rearward to adjust the chain drive tension. Skid steer chain tension should be checked every 500 hours or every three months. If the machine is operated on hard surfaces, the tension should be checked more often. Steel tracks installed around the skid steer rubber tires can cause more stress and wear and tear on the chain drives and require the chain tension to be checked more often. Adjusting Chain Tension on Caterpillar Skid Steers Be sure to follow the manufacturer’s service procedures for adjusting skid steer chain ten- sion. The process for adjusting a Caterpillar skid steer chain drive is as follows: 1. Place the skid steer on jack stands. 2. Remove the drive chain case cover. Note that the cover is located above the oil level. If the chain case is properly filled, the oil does not need to be drained from the chain case. 3. Loosen the eight nuts that secure the axle housing to the skid steer. 4. Rotate the drive wheel to eliminate the slack at the bottom of the chain. 5. Place a straightedge across the top of the sprockets and measure the amount of chain slack (chain deflection). The chain should have 0.6″ (15 mm) of deflection. 6. Place an adjusting tool between the two axle housings to spread the housings in order to achieve proper tension on the chain. 7. When the chain tension is within specification, tighten and torque the axle housing’s eight nuts to specification. Note Late-model Bobcat skid steers have fixed axles and maintenance-free chain cases. Technicians do not need to adjust the chain drive tension on these machines. Goodheart-Willcox Publisher Figure 17-30. The chain drive fill plug is near the bottom of the side of the skid steer. The drain plug is not visible because it is located underneath the frame. Fill plug