Jim's Cushman Scooter Site
Cushman Technical Bulletin
The article below was reproduced
from copy of an original Cushman Technical Bulletin issued in February, 1959 and
it covers the removal, overhaul, and replacement of the disc clutch.
The original print of the article was too blurry to post here and it was
scanned into a word processor with optical character recognition software. The
text is identical but the page layout and font used are different from the
The clutch discs are disengaged when the engine is running at idle speed. As the
engine speed is increased, the discs are forced together by action of
centrifugal weights. When gear shifting is desired, the discs are disengaged
with the clutch pedal. When the engine speed drops down to idle speed, the
clutch automatically disengages.
The clutch hub is mounted on needle bearings. These should be cleaned and
repacked at least every six months, or 2500 miles.
Needle bearings are very hard and
wear- resistant, but very small, so considerable care should be taken to keep
them clean and proper position during packing. Remove all dirt from the clutch
and engine with compressed air if possible. Be sure that the grease used in the
bearings is free from dirt particles.
Remove the belt from the clutch. Disconnect the release lever from the release
rod, and lift the throw out bearing from the clutch.
Remove the nut and lock washer from the crankshaft. Place a knockout of the
proper size and thread it on the crankshaft and screw it down tight. Be sure
that the end of the crankshaft rides on the bottom of the knockout; otherwise,
the threads on the crankshaft will be damaged. Place a bar behind the clutch in
such a position as to pry the clutch off. Pull on the bar and strike the
knockout a hard sharp blow with a heavy hammer. Repeat this process until the
clutch comes free, checking the knockout for tightness between each blow.
The needle-bearing sleeve will probably stay on the crankshaft when the clutch
is removed. Leave it in this position and clean off any accumulation of dirt and
old grease. If the sleeve should come off with the clutch, merely hit it out of
the needle bearings, and clean it.
Inspect the needle bearings. If the needles do not run parallel to the
centerline of the crankshaft, they are badly worn and should be replaced.
Likewise, if there are spaces between the needles and they do not fill the
bearing race, or if any of the needles have a flat side, they should be
replaced. Installation of new needle bearings requires special tools and we
recommend that you have this done by your authorized Cushman dealer.
Clean the needle bearings and
apply a thin coat of lithium base grease to the bearings and to the space
between the bearings. Do not over-pack bearings, because excessive grease will
leak out and get to the clutch linings, but be certain all needles have a
liberal coating. Coat the bearing sleeve with grease before replacing clutch.
Replace the bearing sleeve (if removed), and the key on the crankshaft, and
then, replace the clutch, being sure that the keyways are lined up and that the
key is in the proper position. Replace the lock washer and nut on the crankshaft
and tighten. It is of the utmost importance that the clutch nut be tight at all
The distance between clutch facing and floating disc should be 1/32" to
3/32". This adjustment is maintained by removing shims, as facings wear, or
adding shims when new facings are installed. These shims are on drive pins which
connect the clutch discs to drive flanges. To remove these shims, loosen the
nuts holding the clutch together and cut shims off with side-cutting pliers and
Tighten nuts. When new clutch facings are installed, replace the shims. (See
Fig. 19) CLUTCH RELEASE: The clutch release lever should have 3/8"
clearance between it and the clutch throw out bearing when the engine is
stopped. If this adjustment is not maintained the clutch will either slip or not
Loosen the adjusting nuts on the clutch pedal rod and adjust them so that a
3/8" bolt can be inserted between the release lever and the throw out
bearing. Tighten the adjusting nuts securely
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