SEAL-O-RING 0335853 - Caterpillar

3508 (97Y695-Up),
3512 (1LM62-Up, 51Y736-Up),
3516 (28Z636-Up) Industrial;
3508B (2BM1-Up, 7SM1-Up),
3512B (7HM1-Up, 4TN1-Up),
3516 (4MJ172-Up),
3516B (8CN1-Up, 8KN1-Up) Marine EnginesA new procedure is used for installing the drive gear on the scavange oil pump on the above engines.
1. Press the 7W-7153 Gear onto the 1W-8512 (or 2W-6620) Shaft with 908 kg (2000 lb) of force.2. Tighten the bolt to a torque of 100 N m (75 lb ft).3. Repeat Step 1 and 2, (one time).The 8N-9164 Scavenge Oil Pump Groups starting with pump serial number 3049 were assembled with the new procedure. 1W-8508 Scavenge Oil Pump Groups starting with pump serial number 2699 were assembled with the new procedure. See the charts for effectivity.
Typical view of the 1W-8512 or 2W-6620 Scavenge Oil Pump Shaft (1), and 7W-7153 Gear (2), and bolt (3). Location of pump serial number (A), and typical break location (B).
The above method should be used so that the gear does not come off during operation, or damage the shaft during the installation process. If too much force is used when installing the gear, the shaft can be damaged and could break. If too little force is used when installing the gear, the gear could come off the shaft during operation. In either case, oil can accumulate in the rear section of the oil pan. This can lead to a problem of the crankshaft whipping the oil, causing the oil to blow out of the dipstick or breathers. This can cause low oil level and low oil pressure. See the illustration for the typical location of the break on a damaged scavenge oil pump shaft (B).