A Caterpillar 578 Pipelayer, Complete Overhauling of 3406 Engine

An unexpected breakdown of a Caterpillar 578 pipelayer, one of the two mean pipe lifters of Sui Northern Gas Pipelines Limited has stirred things around me recently.

Many a theories mushroomed right in front of me with in no time. This was infact a true reflection of all that had earlier been told to me about my present place of posting. Blame game is the name of the play everywhere, at least in SNGPL. No one is ready to accept his responsibility as it takes great courage to do this. I am no exception either.

True might of CAT 578 pipelayers stands out on pipelines of at least 36 inch diameter. A moving room perhaps is the best simile for this wonder. I have seen things like shaking ground, behaving spongy around this machine. The airflow in front of the radiator of this machine is just awesome.

Anyhow, this machine is now out of order due to an unanticipated engine breakdown. A careful examination of the oil pan of the said machine revealed metal pieces probably of the Big End Bearings of first cylinder. Interestingly this cylinder was the cause of breakdown about a year ago when we replaced the pitted first and second Cylinder Liners of this machine after receiving complains of water contamination in the oil pan. On hearing this, a connoisseur in my team of esteemed mechanics presented a childish theory. For him this wreck was due to either over torque of the bolts or mistakenly turned around connecting rod of the first cylinder. Whereas, to me defective fuel injector nozzles of the machine which were spraying excessive fuel on the pistons as well as seepage of fuel in the oil pan were the real culprits. This pipelayer was performing adequately in my previous place of posting where the maintenance crew used to carry out frequent oil changes to drain contaminated thinned engine oil. Though such practices might invoke audit observations in public sector organizations but the cost of frequent oil drains bears no comparison with the price of such a mighty machine.

Anyway, I have indented following parts for complete engine overhauling of its 3406 engine which will be available to me in the coming 6 months at least.

CAT PIPELAYERS 578
Machine Serial No.	8HB00497
Machine Arrangement No.	9P7398
Engine Model	CAT 3406
Engine Serial No.	11N06096
Engine Arrangement No.	9P7398
Winch Serial No.	9CA00428
Winch Arrangement. No.	4P7433

Engine Overhauling Kit for Two Machines consisting of
LINER CYLINDER	7W3550	12	NOS.
PISTON GP	1W9373	12	NOS.
RING GP PISTON	1W8922	12	NOS.
PIN PISTON	8N1608	12	NOS.
RETAINER PIN	8N7295	24	NOS.
ROD ASSY. CONNECTING	8N1726	12	NOS.
BEARING SLEEVE	4N0685	12	NOS.
BEARING SLEEVE	4N6658	02	NOS.
SEAL GP CRANK SHAFT	2W1734	02	NOS.
SEAL GP CRANK SHAFT	2W1733	02	NOS.
BEARING MAIN .050" US	4W5699	07	NOS.
BEARING MAIN .025" US	4W5698	07	NOS.
BEARING CONNECTING ROD .025" US	4W5702	06	NOS.
BEARING CONNECTING ROD .050" US	4W5703	06	NOS.
PLATE THRUST	7N8947	04	NOS.
GASKET CENTRAL & LOWER STRUCTURE	8T4868	02	NOS.
GASKET FRONT STRUCTURE	9X6474	02	NOS.
GASKET SINGLE CYLINDER LINER	5P8057	12	NOS.
GASKET SINGLE CYLINDER HEAD	7X2632	02	NOS.
SEAL O RING (TURBO)	2M5173	04	NOS.
SEAL WATER	4W1055	48	NOS.
VALVE INLET	2W2622	24	NOS.
VALVE EXHAUST	1W3860	24	NOS.
VALVE GUIDE	4N2803	48	NOS.
INSERT INLET	4N5893	12	NOS.
INSERT VALVE SEAT EXHAUST	1W5283	12	NOS.
PUMP GP WATER	7C4957	02	NOS.
PUMP GP ENGINE OIL	4N0735	02	NOS.
Fuel Injection System for Two Machines consisting of
PLUNGER & BARREL ASSY.	2W3414	12	NOS.
VALVE ASSY. CHECK	1W6982	12	NOS.
NOZZLE ASSY. VALVE	7W7032	12	NOS.
ADAPTER NOZZLE	7W5435	12	NOS.
PUMP GP FUEL PRIMING	8N6200	02	NOS.
PUMP GP FUEL TRANSFER	1W1700	02	NOS.
Cooling System for Two Machines consisting of
CORE ASSY. OIL COOLER	7N0113	02	NO.
CORE GP OIL COOLER	4W9822	02	NO.
Winch System for Two Machines consisting of
PUMP GP GEAR	1U2756	02	NOS.
SEAL O RING	6V1175	04	NOS.
RING SEAL INT	8P8746	02	NOS.
01 No. Seal Kit for Boom Hydraulic Jack consisting of
SEAL ASSY.	8T1794	02	NOS.
RING WEAR	9J3369	01	NOS.
SEAL O RING	5P2235	01	NOS.
RING BACKUP	1U3307	01	NOS.
SEAL LIP TYPE	8C5220	01	NOS.
SEAL CUP	5J8400	01	NOS.
SEAL ASSY.	8C9129	01	NOS.
RING WEAR	8T6747	01	NOS.
01 No. Seal Kit for Weight Hydraulic Jack consisting of
SEAL AS	8C9126	01	NOS.
RING WEAR	7J5326	01	NOS.
SEAL AS	4T4144	01	NOS.
SEAL-O-RING	5H3252	01	NOS.
SEAL-BACK-UP	2K3258	01	NOS.
SEAL-U-CUP	5J8300	01	NOS.
SEAL-LIP TYPE	8C5218	01	NOS.
RING-WEAR	9T0094	01	NOS.