WinGD RT-flex50DF, Maintenance Manual, Page: 259 / 586

Maintenance
3303 − 1/A1
Winterthur Gas & Diesel Ltd.
3/ 5
3. Tensioning the stud of bottom end bearing
1) Clean the threads of studs 4 and the area around the nuts 5.
2) Apply oil to the stud threads and screw on the nuts.
3) Tighten the nuts with round bar ’RS’ and equally distribute clearance ’y’ between
the bearing halves (bearing protrusion) as shown in Fig. 2.
4) Put the distance bushes 94314A on the studs.
5) Attach and tighten the pre-tensioning jacks 94314 with open vent screws 7 until
there is only little or no clearance at ’x’ (Fig. 3).
6) Connect the pre-tensioning jacks to hydraulic unit 94942 as shown in Fig. 2.
7) Actuate the hydraulic unit until bubble-free oil flows out through the vent screws.
Close vent screws.
8) Actuate the hydraulic unit and set the pressure to 950 bar (1
st
step) and keep
pressure constant.
Pistons 8 of the pre-tensioning jacks must never exceed the red limiting
grooves ’BN’ (Fig. 3).
Tighten the nuts with round bar ’RS’ and check with the feeler gauge through
slot ’KO’ (Fig. 3) that no clearance remains between nut and supporting
surface.
Check with the feeler gauge that no clearance remains between bearing cover and
connecting rod.
(Should clearance remain, loosen the fastening and compare the bearing protrusion with
the nominal value as indicated in 3303 − 2 ).
9) After tensioning to the 1
st
step mark the
position of the nuts against connecting
rod as shown in Fig. ’a’.
10) Raise the pressure to 1500 bar (2
nd
step) and keep it constant.
Tighten nuts down and check correct
seating with the feeler gauge.
Check from the markings applied by how
much the nuts were turned after
pre-tightening (1
st
step).
Tightening angle to be about 30 _ (Fig. ’b’).
11) Should considerable differences to
these nominal values be encountered
then repeat the tensioning process.
12) Release pressure to ’0’ at the hydraulic
unit and then remove pre-tensioning
jacks.
Finally check the vertical bearing
clearance (see Clearance Table 0330 − 1
’Top and bottom end bearings to
connecting rod’).
2016
Loosening and Tensioning the Connecting Rod Studs
TIGHTENING
ANGLE
x
y
Fig. ’a’
y
Fig. ’b’
009.752/02
013.430/05
x