Gearbox Oil Seals

From: "Walter Overfelt"
To: <Jay>
Date: Sat, 22 Jul 2000

Unless they (Cavalcade owners) are replacing the three seals that are associated with that gear box, they may be wasting their time.  Read following:

1.  If the seal that is by the u-joint has failed, there will be gear oil in the drive shaft boot. resulting in loss of gear oil in the bevel gear box.

2.  If you notice a slight LOSS of engine oil with no explanation (smoky exhaust, engine oil leaks, etc.) CHECK bevel gear box for high oil level, IF its HIGH and you didn't over- fill it, then the seal BETWEEN the gear box and the crankcase has failed,
allowing engine oil to enter bevel gear box (as this oil is under engine oil pressure). IF you continue to run under these conditions, you will over fill the gear box with ENGINE OIL which WILL either come out of the bevel gear box BREATHER TUBE, or lead to failure of REAR SEAL AT THE U-JOINT.

3. ANY TIME the bevel gear box is removed for any reason, it is a good IDEA to REPLACE ALL THREE SEALS in the bevel gear box, as this is a very time consuming job. The three seals are as follows:

    A.  Rear Seal   item #1 

    B.  Main Shaft Seal   item#15

    C.  Clutch Shaft Seal  (not shown)

Unless you check this out, your mechanic may just change the rear seal.