Click here to make tpub.com your Home Page

Page Title: Crankcase Assembly
Back | Up | Next

Click here for thousands of PDF manuals

Google


Web
www.tpub.com

Home


   
Information Categories
.... Administration
Advancement
Aerographer
Automotive
Aviation
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Logistics
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
   
   

 

TM 55-4920-405-13&P
to the end of the crankshaft. Pry the
4.
Put the connecting rod cap on the
crankshaft gear off the crankshaft with
removed connecting rod at once
a wedge type tool.
so that the caps and connecting
rods will not be mismatched when
NOTE
you reassemble the crankcase
assembly. If your engine uses
The mounting holes in the crankshaft gear
babbit bearing rods, make sure
are staggered so that the gear can be in-
that the shims are in place before
stalled only one way. This ensures that
you put on the cap.
the gear will be automatically timed to the
5.
Replace the piston rings if neces-
crankshaft.
sary. Use a ring expander tool.
If you do not have a ring expander
(b) Remove the Allen head setscrew on
tool, install the rings by placing
the magneto side of the crankcase.
the open end of the ring on the
(See figure 4-17.) This setscrew
piston first, as shown in figure
locks the idler shaft in position.
4-20. Spread the ring only enough
Using a gear puller, remove the idler
to slip it over the piston and into
shaft and idler gear assembly from
the right groove. Be careful that
the crankcase.
you do not distort the ring. In-
(c) Remove the locknut and oil pump gear
stall the bottom ring first, and
(figure 4-16) from the oil pump gear
work toward the head of the pis-
shaft. Use a gear puller. Do not
ton, installing the top ring last.
hammer on the shaft because this will
(See figure 4-21.) Mount the
damage the oil pump.
scraper ring with the scraper
(d) Remove the oil pump as follows:
edge down; otherwise, oil pump-
ing and excessive oil consumption
1.
Take out the slotted pipe plug
will result. Stagger the piston
from the bottom of the crankcase.
ring gaps 90 degrees apart a-
round the piston.
2.
Using a 5/32 inch Allen wrench,
remove the lockscrew from the
(f) Remove the crankshaft as follows:
pipe plug hole.
3.
Withdraw the oil pump from in-
1.
Remove the screws and lock-
side the crankcase. If it fits too
washers that attach the main
tightly to remove it by hand, tap
bearing plate and remove the
the front end of the oil pump
main bearing plate from the crank-
housing (not the shaft) with a
c a s e . (See figure 4-22.)
hammer and brass rod to loosen
2.
Carefully take out the crankshaft
it.
from the same end of the
crankcase.
(e) Remove pistons and connecting rods
as follows:
(g)
Remove  the
valve
tappets.
(See
1.
Using a 9/16 inch socket wrench,
remove the hex nuts from the
connecting rod bolts.  (See figure
4-19.) Tap the ends of the bolts
lightly to break the connecting rod
cap free from the bolts. Remove
the connecting rod cap.
2.
Scrape off all carbon deposits
that might interfere with removal
of pistons from the upper end of
the cylinder.
3.
Turn the crankshaft until the
piston that you want to remove is
at the top. Then, push the con-
necting rod and piston assembly
up and out through the top of the
cylinder. Be careful that you do
not mar the crank pin by letting
the rod bolts strike it or scrape
across it.
4-30

Privacy Statement - Press Release - Copyright Information. - Contact Us

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business