TURBOCHARGER GP 2635446 - Caterpillar

In any exchange of rebuilt water pumps, keep the "TRB" pumps separate from the "pinned" pumps. See the topic "Pump Identification and Application".Pump Identification And Application
Tapered Roller Bearing (TRB) Pumps: The 2W1223 and 1W6446 Water Pump groups have tapered roller bearings, and use the 6V6896 Rebuild Kit. Installation of the kit (which has the new 2W712 Seal Assembly) and the new impeller (or the addition of two holes to the existing impeller) will make the 1W6446 Pump basically the same as the 2W1223 Pump. For reconditioning, use the procedure given in the second reference article.
Identification of the TRB pumps can be made by the nut on the end of the shaft, and the part number "1W5644" on the housing as shown in the illustration. Also, the TRB pumps do not have the retainer with six socket-head bolts on the end of the housing. Use these pumps as a direct replacement for all earlier pumps in all engine applications.
"Pinned" Ball Bearing Pumps: The 1W2929 Water Pump Group has ball bearings, with a pin lock to hold the rear bearing race (pinned) to the housing. For reconditioning, use the 6V6895 Rebuild Kit (which has the new 2W712 Seal Assembly), add holes to the impeller, and follow the procedure given in the Service Manual. These pumps are no longer available.
Identification of the "pinned" bearing pumps can be made by the nut on the end of the shaft, the part number "8N5796" on the housing, and the retainer with six socket-head bolts on the end of the housing.
Both "TRB" and "pinned" bearing pumps have the nut on the end of the shaft, but earlier "non-pinned" ball bearing pumps do not.Rebuilt pumps with "pinned" bearings can be used for service replacement on 3204 Engines in applications where the fan is not installed on the pump, and will give acceptable service life. In applications where the fan is installed directly on the pump, the recommendation is to use only the "TRB" pumps for maximum service life.
"Non-Pinned" Ball Bearing Pumps: Earlier ball bearing pumps did not have a pin lock to hold the bearing race (non-pinned). These pumps are no longer available, and no rebuild kit is available for reconditioning.
Identification of these earlier pumps can be made by the bolt used in the end of the shaft. This bolt has a twelve-point head. See the illustration.
Comparison of water pump designs for 3204 Engines.