Assembly and Adjustment of Cummins 6BT Series Diesel

by MOU YONG HONG on December 01, 2021

In this article, the VEP DIESEL PART company mainly shares the way to assemble and adjust Cummins 6BT Series diesel of generator set.

1.Assembly of the engine block

A. Before assembles, should clean engine block. All oil passages, main bearing holes, camshaft holes, tappet holes, and screw holes shall not have burr edges and shall be blown clean with compressed gas. No foam, molding sand, and iron chips. Wash with gasoline and white silk cloth until the cylinder and other moving parts are cleaned by sticking machine oil with toilet issues. there's no dirt on toilet tissue that the cleaning is qualified;

B. Press bowl plug into vessel hole and main oil passage hole of the engine block, before pressing, should uniformly smear GY-255 anaerobic adhesive on the surface of bowl-shaped plug cylinder;

C. Main bearing head and engine block must be paired and assembled. The chamfered side of the most bearing cover (marked in sequence) faces the pump side. Each bolt hole of the most bearing cover features a positioning ring for location. Should keep the joint surface of bearing cap cleaned and wiped with a non-woven or silk cloth;

D. In the course of delivery should make sure the top, bottom, and kit chamber surfaces of engine block aren't damaged;

E. Press the flywheel positioning ring, plate positioning ring, and kit chamber positioning ring into the corresponding seat holes of the engine block with special tools, and therefore the positioning ring should be pressed in situ without deviation;

F. The installation position of the booster return pipe is at the lower right a part of the engine block. Before assembly, should coat GY-255 anaerobic glue on the lower end of the return pipe, and press into the shoulder with special tools. The return pipe and therefore the hole of the supercharger is in transitional coordination - 0.11mm-0.01mn.

2.Installation of tappet body

The fit clearance between the tappet body and therefore the hole is 0.02mm to 0.065mm. Before assembling the tappet, use 15W40 grease to lubricate the opening of the engine block tappet, and use grease to lubricate the bottom surface and inner socket of the tappet body. The tappet body shall completely be located within the hole of the tappet body and may rotate freely.

3.Installation of the crankshaft, gear, and spindle bush

A. Firstly, check whether there are scratches or other defects on the surface of the crankshaft journal. Install the positioning pin, the min protrusion of the positioning pin is 1.8mm. Before loading the gears, heat the gears during a furnace at 150 ℃ for 1 hour. Check the timing marks and defects situation of the gears. When installing, turn the chamfered side towards the crankshaft. After the gear is pressed into the crankshaft, it should be tightly attached to the crankshaft shoulder and checked with a 0.05mm plug ruler. It shouldn't be stuffed into the crankshaft. Install the most bearing bush on the most bearing seat and therefore the main bearing bush seat of the cylinder block;

B. Install crankshaft journal bearing bush on the sixth main bearing. When installing, should use grease 105 to coat on bearing bush inner surface and thrust bush thrust surface and coat grease 15W40 on journal surface;

C. The clearance between crankshaft and hole is 0.041mm to 0.119mm. Before loading the crankshaft into the engine, the surface of the journal, should clean carefully inclined oil passage and bearing seat. Sand inclusion and flying edge aren't allowed on the non-machined surface of the crankshaft.

4.Installation of piston and rod

A. Check the cleanliness and defects situation of the piston, rod, piston pin, and piston pin elastic ring. The clearance between the piston pin and the piston pin seat hole is 0.0028mm to 0.0172mm. Before assembly, the piston is often heated to 50 ~ 70 ℃ (or not heated, assembled by matching method). When the piston's leading sign is upward, the rod cover should get on the proper side (from top to downward). The piston pin should be coated with 15W40 lubricant then smoothly pushed into the piston pin hole and therefore the rod small head hole. The piston pin should be ready to slide freely into the piston pin;

B. Piston ring assembly. Before installing the seal, brush the seal groove with a clean brush dipped in 15W40 lubricant.

5.Installation of drugs chamber

A. Check the cleanliness of the mounting surface of the gear room or the defects caused during transportation;

B.Firstly, press the positioning pin into the positioning pinhole of the front face of the engine block. Then, install the gear chamber.

6.Installation of the pump assembly

A. Check whether the pump and engine block are defective. Rotate the pump, check whether the pump can rotate freely;

B. Use 15W40 grease to lubricate engine oil pump;

C. Fill the lumen of the pump with CD grade 15W40 oil.

7.Installation of Wheel Shaft and Tappet Body

A. Install camshaft gear. Before assembling, the gears should be kept warm for a minimum of one hour within the furnace at 125 ℃. When pressing the gears into the camshaft, it's necessary to make sure that the keys are aligned with the keyway in which the gears are on the brink of the shoulder of the shaft. The gears should be inspected with a 0.05mm plug ruler and not be stuffed in;

B. Installation of the camshaft. Before installing, use 15W40 grease to lubricate the camshaft journal and cam peach.

8.Installation of timing pin seat and pump

A. Rotate the crankshaft, in order that it's at the dead point on the cylinder. Check whether the timing mark on the crankshaft gear is aligned with the timing mark on the camshaft gear;

B. Install timing pin seat on the mounting hole of the drugs room;

C. Check cleanliness and defects situation of pump and gasket and check whether the manual valve rocker can swing freely.

The above information is a few methods of assembly and adjustment of the Cummins 6BT series diesel. If you'd wish to get more information, or produce other technical problems, or curious about Cummins diesel generator set, welcome email to, our VEP DIESEL PARTS worker will offer you a professional and satisfying reply.


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