Assembly - Tecumseh TC Series Technician's Handbook

ASSEMBLY

1. Remove old gasket material. Be careful not to damage
scratch or burr the sealing surfaces. Clean the
crankcase, cylinder, piston assembly, crankshaft, and
crankcase cover using cleaning solvent and blow dry
with compressed air (diag. 7-13).
2. On TC type II engines with a ball bearing on the P .T.O.
end, assemble the crankshaft into the cylinder cover.
Place a drop of 680 Loctite in the crankshaft groove,
position supports under the cylinder cover, and using
an arbor press, press the shaft into the bearing until it
bottoms on the bearing.
3. Install the crankshaft and piston assembly into the
crankcase at the same time. Install a new bearing strip
on the crankpin or grease retain the loose needles if
applicable. If the piston has an arrow on top, the arrow
must point toward the exhaust port side of the engine.
If the piston does not have an arrow, the piston and
rod assembly must have the wrist pin retainer facing
the P .T.O. side of the engine. Position the crankshaft
crankpin at 90° to top dead center while sliding the
piston assembly over the crankshaft. Do not use force
positioning the assembly (diag. 7-14).
4. Install either a new crankcase cover "O" ring and lightly
oil if one was originally used, or apply Loctite # 515
gasket sealant eliminator (Tecumseh part # 510334)
to the crankcase surface to seal the crankcase cover.
Apply a continuous bead of Loctite (.062" [1.57 mm]
bead width) on the crankcase surface. The bead must
completely surround the tapped holes for the cover.
Loctite must not enter the crankcase (diag. 7-15).
5. Align the crankcase cover to the proper position using
the mounting bolts as a guide. Do not allow the cover
to rotate while assembling. Tighten the bolts to achieve
70 - 100 inch pounds (7.9 Nm - 11.3 Nm) of torque.
6. Install the crankcase oil seal using seal protector (part
# 670301) on crankcase oil seal. The metal case of
the seal must face toward the tool. Press the tool flush
to the crankcase.
7. Install crankcase cover oil seal using seal protector /
installer part # 670303 to protect the oil seal during
installation. The metal case of the seal must face
toward the tool. Press the tool flush to the cover.
8. Apply mineral spirits or kerosene to the crankpin
bearing and rotate the crankshaft to dissolve the wax
of a new needle bearing strip. Apply engine oil and
rotate the crankshaft to displace the grease used to
hold the needles in place on grease retained crankpin
bearings.
9. Install cylinder gasket (notched edge toward the
cylinder cover and the exhaust port side of cylinder),
or apply a .062" (1.57 mm) bead of Loctite # 515 to
the cylinder crankcase surface if Loctite was originally
used. The Loctite bead must completely surround the
cylinder bolt holes. Loctite must not be allowed to enter
the crankcase.
10. Use a piston and rod holder (dimensions are in Chapter
9 tool section) to prevent damage to the rod when
installing the cylinder. Make sure the ring end gaps
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.062" (1.5 mm)
Bead of Loctite
7-13
7-14
"O" Ring
7-15
7-16
31