Cleaning, inspection, and repair. - TM-55-1925-204-120263

Custom Search

Figure 5-36. Crankshaft front cover attaching hardware tightening sequence.

TM-55-1925-204-12 TUG Harbor Diesel 1200 H. P. Steel 100 Ft Design 3006 Flight One FSN 1925-375-3003 Manual

Figure 5-37. Checking cranking end play.

ridge, followed by 240 grit for finishing. Then, wet crocus

then hoist engine high enough for access to oil pan and

cloth should be used for the polishing operation.

bearing caps.

3. If the ridges are greater than

(h) Block engine for safety, but leave hoist

0.001 inch, the crankshaft must be reground at higher

attached with strain on lifters.

maintenance.

(i) Remove oil pan. and lubricating oil

4. Inspect crankshaft for cracks.

pump (c. (1) (d) above).

Replace a cracked crankshaft.

(j) Remove flywheel and housing (para 5-

5. Inspect the oil pump drive gear

6).

(9) for cracks or broken teeth. If cracked, or teeth broken,

(k) Remove crankshaft front cover If.(1)

replace the oil pump drive gear.

above).

6. Inspect the crankshaft timing

(l) Remove the connecting rod bearing

gear (3) for cracks. or broken teeth. Replace a defective

caps, rods, (para 5-4).

timing gear.

(m) Remove the main bearing caps (c. (1).

(d) Repair a crankshaft by replacing

(e) above), but tag them for identification at reinstallation and

components. Replace a defective crankshaft.

remove all, at this time.

(n) Remove crankshaft (10, fig. 5-31).

(3) Installation.

(2) Cleaning, inspection, and repair.

(a) Clean the crankshaft by removing plugs

NOTE

from crankshaft and thoroughly cleaning all oil passages.

If a new crankshaft is to be installed, it

(b) Support the crankshaft on V-blocks at

must be, or have been, steam cleaned to

the front and rear journals, and check the alignment at the

remove rust preventive compound, and

adjacent intermediate journals by using a dial indicator.

meet the dimensional requirements shown

throughout subparagraph (2) above.

NOTE

When runout on adjacent journals is in the

(a) Install the grooved upper main bearing

opposite direction, the sum must not

halves in the cylinder block.

exceed 0.003 inch TIR (total indicator

(b) Apply clean engine oil to all crankshaft

reading). When the runout on adjacent

journals. and place the crankshaft in cylinder block so that

journals of the four cylinder crankshaft is

the timing gear mark (R or L) meshes with the idler gear mark

in the same direction, the difference must

(fig. 5-29).

not exceed 0.003 inch TIR. If the runout at

thrust washers on each side of the upper and lower rear main

journals No. 2 and 4 is greater than 0.002

bearing (c.(3) (b) above).

inch, or runout at journal No. 3 is greater

(d) Install lower bearing halves in bearing

than 0.004 inch, the crankshaft, must be

caps, then position bearing caps on like numbered journals.

replaced.

and secure with bolts (6, fig. 5-31) drawn up snug.

(e) Rap the bearing caps sharply with a

soft hammer, and torque as described in c.(3) (c) above.

groove in upper bearing half. If a ridge of 0.0002 inch exists,

it must be removed before the bearings are reinstalled.

NOTE

Proceed as follows:

If the bearings have been properly

1. Work a piece of crocus cloth, wet

installed, the crankshaft will turn freely

with fuel oil, around the circumference of the journal. Rotate

with bolts torqued to specifications.

the crankshaft frequently during this process to eliminate an

out-of-round condition.

(f) Use dial indicator installed at edge of

2. If the ridges are greater than

the crankshaft timing gear to measure crankshaft end play

0.0005 inch, first use 120 grit emery cloth to clean up the

(fig. 5-37).

5-43