CX28 Military On-Highway Transmission Caterpillar

Preparation for Installation of the Transfer Gear and Case

Inspect the transfer gear and case before installation.

Case Leak Check

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Illustration 1	g03096338
Front view (1) Breather (2) Input shaft (3) Output yoke

Note: Install a cap on the suction and inlet ports for the lube fitting of the manifold.

Note: It is essential to fill the housing with air at 0.035 MPa (5 psi) and hold the system under pressure. Do not exceed 0.05 MPa (7 psi). Higher than 0.05 MPa (7 psi) may push the seals out from the housing.

1. Connect an air line (roughly 0.035 MPa (5 psi) to the breather (1) by using a quick disconnect and a pressure gauge. Hold the system under pressure for approximately 10 minutes and check for a pressure drop.

   Note: An air leak will be a good indication that there is an oil leak, is if there is an air leak.

Spin Check

Note: A spin test is needed in order to determine that the seals are not leaking oil.

1. Connect to the input shaft (2) of the transfer gear. Spin the shaft for a total of 30 minutes. Perform this function in "high", "low", and "reverse". Monitor the housing temperature in the bearing areas. Listen for abnormal noise. Check the seals on the yokes (3) to determine if oil is leaking.

Solenoid Check

Illustration 2	g02652997
(3) Output yoke (4) Ball switch

1. Connect an air line (0.7 MPa (100 psi)) to the manifold and apply 12 V DC current to each solenoid. The current will test to make sure the shifters move. The sound of shifting and turning the yokes by hand will show you what shifter moved or did not move. When shifted in low, check that the ball switch (4) turns on. When the differential is locked, the differential should not be able to turn the front output yoke without letting the rear turn the same way at the same speed. Also when in "low" gear, you can see that the input yoke turns more than the output yoke.