F700 Series
Disassembly and Re-assembly Procedure
(For Item Identification, Refer To Exploded View)
Output Shaft Disassembly
1. Remove vented filler (Item 26), and the most convenient
pipe plug (Item 27) and completely drain oil.
2. Remove bearing carrier screws (Item 24) from projecting
shaft bearing carrier (Item 9). Remove carrier by
CAREFULLY sliding it over the projecting shaft diameter.
3. Output shaft assembly (Items 2, 3, 5 &6) can now be
removed from the unit. Exercise care not to nick or
scratch worm gear or shaft diameters.
4. Visually examine the output shaft assembly. Check
tapered roller bearings (Item 6) for signs of metallic
contamination or discoloration. Rollers should have
continuously smooth action and should not bind or exhibit
“flat-spots”.
5. Note that replacement parts for output gear (Item 2) will
include an output shaft assembly (Items 3 OR 4) for sizes
F710 through F726. Also included are items 5, 6, 11, 12
and 23.
Input Shaft Disassembly
Models F710 through F730
1. With a screwdriver or suitable tool, pierce the bore plug
(Item 19) and remove from the housing bore.
Models F732 and F738 only
2. Remove fan guard (Item 104). Remove fan retaining
screw (Item 103), fan (Item 101) and spacer. With a
screw-driver or suitable tool, pierce and fan end oil seal
(Item 16) and remove from the housing bore.
3. Remove the outboard retaining ring (Item 17) from the
housing bore. Remove the metal shims (Item 18), located
between the retaining ring and the ball bearing (Item 14).
4. Remove four (4) screws (Item 42) from the motor flange
(Item 40) and remove the flange from the housing.
5. Remove the input worm assembly (Items 14, 38 and 39)
through the bore opposite the flange side. Remove the oil
seal (Item 41) from the housing.
6. Check the condition of the ball bearing (Item 14). The
bearing should roll smoothly and not bind. If the bearing
needs replacement, remove the snap ring (Item 38) and
press the shaft through the bearing.Install new bearing
onto the shaft and re-assemble the snap ring. If the
bearing is not pre-packed with grease, pack at least 50%
full with MOBILUX EP #2 ALL PURPOSE GREASE or
equivalent.
Input Shaft Re-Assembly
Models F710 through F738
1. Insert input worm assembly in the housing. Seat the ball
bearing against the inner retaining ring (Item 17).
2. Install the metal shims (Item 18) and assemble outboard
snap ring (Item 17).
3. Clean the housing bore(s) in the area where oil seals will
be installed.
4. Coat the oil seals as follows:
A. Rubber Clad Oil Seals - Apply ALL-PURPOSE
grease (NLGI #2 consistency) to the I.D and O.D.
B. Steel Clad Oil Seals - Apply ALL-PURPOSE grease
to the ID only and coat the bore evenly with
Permatex Form-A-Gasket #3 sealant or equivalent.
5. Insert the new oil seal (Item 41) over the shaft until it
contacts the housing. CARE MUST BE TAKEN NOT TO
DAMAGE THE OIL SEAL LIP.
6. With a small hammer, tap around the face of the oil seal
casing - near the outside diameter. Locate the seal as
shown in Figure 2 Page 14. Use a suitable driving tool.
Model F710 through F730
7. Install a new bore plug (Item 19). Coat the bore with
PERMATEX FORM-A-GASKET #3 OR EQUIVALENT
SEALANT. Using a small hammer, lightly tap around the
plug face near the outside diameter. CAUTION should be
exercised not to distort or cock the bore plug.
Model F732 and F738
8. Install new oil seal on the fan end (Item 16). With a small
hammer, tap around the face of the oil seal casing - near
the outside diameter. Use a suitable tool to assure
squareness of the seal to the bore. Drive the seal flush to
1/16th inch projection. Reinstall fan spacer, fan, washer,
lockwasher, and bolt. Tighten the bolt per the chart in
Figure 5, Page 15. Reinstall the fan guard and tighten the
screws per chart in Figure 5.
Worm Gear Replacement
Model F710 through F726
1. Replace the entire output assembly.
Model F730 through F760
2. Place the output gear assembly into a pressing fixture
and remove the worm gear from the shaft.
3. With the gear key assembled in the shaft key seal, press
the new gear onto the shaft to the dimension shown in
Figure 1, Page 14.
4. Install the shaft spacer (Item 5) and grease cups (Item
34).
5. Press the bearing cones (Item 6) onto the shaft making
sure that the assembly is tight (no space between items).
6. Remeasure from the end of the shaft to the gear face as
shown in Figure 1, Page 14. Readjust, if necessary, by
pressing on the bearing cone until desired dimension is
achieved.
7. Where grease cups are used, pack with Mobilux EP #2
All-purpose grease or equivalent.
9Doc. No. 57746 • Boston Gear® 700 Series Worm Gear Speed Reducers
®
DIST. AUTORIZADO
MEX (55) 53 63 23 31
QRO (442) 1 95 72 60
MTY (81) 83 54 10 18
