Shaft Seals - Simplicity 1691682 Service & Repair Manual

Shaft Seals

Lip type seals are used on the input shaft, output shaft ,
and displacement control shaft of the Series 70 transmis-
sions and pumps. These seals can be replaced without
major disassembly of the unit. However, replacement of
the seals generally requires removal of the transmission
or pump from the machine.
REMOVAL
1. To replace the pump input shaft seal, first remove the
retaining ring from the housing.
2. Carefully pull the seal out of the housing bore. A
"hook" type tool may be used to grasp the seal and
pull it out, or a slide hammer type puller may be used
to remove the seal. Care must be taken so as not to
damage the housing bore, shaft sealing surface, or
bearing. Once removed, the seal is not reusable.
NOTE: Once the pump input shaft seal is removed, the
pump block spring may push the shaft partially out of the
housing. Do not attempt to pull the shaft out of the hous-
ing. Internal parts could move out of alignment or fall into
the transmission, requiring major disassembly of the unit.
INSTALLATION
1. Inspect the sealing area on the shaft for rust, wear, or
contamination. Polish the sealing area on the shaft if
necessary.
2. Lubricate the new seal with petroleum jelly.
3. Wrap the spline or key end of shaft with thin plastic to
prevent damage to the seal lip during installation.
4. Slide the seal over the shaft and press it into the
housing bore. Be careful not to damage seal.
5. Install the seal retaining ring in the housing.
The output shaft and displacement control shaft seals
may be replaced by following a similar procedure. These
seals are not held in position by a retaining ring. The
motor output shaft seal and the Pump Control Shaft are
Flush to Bottomed in the bore.
7B Sauer-Sundstrand BDU-21L-207
Figure B-6. Retaining Ring Removal
Figure B-7. Lip Seal Removal
Figure B-8. Lip Seal Installation
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7 Transmission Repair