Check Du Bearings; Remove Du Bearings - All Models; Install Du Mag Bearing - All Models; Install Oil Seal - Mag Side - All Models - Briggs & Stratton Twin Cylinder L-Head Repair Manual

Check DU Bearings

DU main bearings should be replaced if damaged or if
plug gauge, Tool #19219, will enter bearing. Try gauge
at several locations in bearing, Fig. 5. If gauge is not
available, refer to Table No. 2 for reject dimensions.
Remove DU Bearings – All Models
Place cylinder, sump or crankcase cover on cylinder
support, Tool #19227, with 1-5/8" (41.3 mm) opening
toward bearing to be removed. Place bushing driver,
Tool #19226, in bearing and press into recess of
cylinder support, Fig. 8.
Install DU Mag Bearing – All Models
NOTE: Engine models 400440, 402440 404440
and 422440 have a full pressure lubrica-
tion system. Engines manufactured before
date code 89730000 were equipped with
DU bearings with a machined oil reservoir,
Fig. 11. Refer to illustrated parts list for
correct bearing number by model and date
code.
Place cylinder on cylinder support, Tool #19227, with
1-5/8" (41.3 mm) opening toward bearing to be
installed. Fig. 9. Place DU bearing against counter-
bored bearing, making sure that oil holes align. Insert
bearing driver, Tool #19226, into DU bearing and press
in until the DU bearing is 1/8" (3.0 mm) from thrust face
of cylinder, Fig. 9.
NOTE: Be sure oil hole in DU bearing is aligned
with oil hole in cylinder bearing.
To prevent bearing from turning, stake bearing from
both sides with 1/4" (6.3 mm) round pin punch, Fig. 10.
Install Oil Seal – Mag Side – All Models
Install oil seal with the sealing lip facing the inside of the
engine. Use cylinder support, Tool #19227, and press
in new oil seal until flush with cylinder.
Always install new oil seals whenever engine is
disassembled for major servicing or when repairing or
replacing bearings. Always use the correct seal
protector to prevent damaging oil seal.
10
#19226
DU
BEARING
#19227
Fig. 8 – Remove DU Bearing (Typical)
OIL HOLE
#19226
#19227
Fig. 9 – Pressing DU Bearing
45°
30°
Fig. 10 – Staking Bearing
1/8"
(3.0 mm)
THRUST FACE
DU
BEARING
5