CHAINS AND SPROCKETS
Paragraph
Adjust front chain 59
Adjust rear chain and aline rear wheel 60
Chain oilers 61
Replacement of front chain 62
Replacement of rear chain 63
Chain repair tool 64
Replacement of engine sprocket 65
Replacement of countershaft sprocket 66
=59. ADJUST FRONT CHAIN= (figs. 36, 37, and 38).
=a.= At the time front chain adjustment is made, inspect chain for
correct lubrication and, if necessary, adjust front chain oiler (par.
61).
=b.= Chains wear unevenly and some stretch may result, making tight
and loose sections. For this reason, engine must be turned and chain
rotated to position of least slack at the time adjustment is made.
=c.= A correctly adjusted front chain has 1/2-inch, or slightly more,
free up‐and‐down movement midway between sprockets, at inspection
hole. Chain must never be run taut (no slack at tightest point). Chain
must never be allowed to run loose enough to cause jerky, noisy action
and/or strike the chain guard.
=d.= Adjustment of front chain is made by shifting transmission on its
mounting base. This will affect adjustment of gear shifter control
linkage, clutch control linkage, and rear chain.
=e. How to Adjust Front Chain.=
(1) Remove inspection hole cover by removing screws and lifting cover
from front outer chain guard, exposing chain (fig. 36).
(2) Obtain tightest chain position by rotating chain to position of
least slack. Test amount of slack by lifting and depressing chain with
finger. Use a free up‐and‐down motion of the finger to make this test.
(3) Loosen the three transmission mounting stud nuts underneath
transmission mounting base. (It is not necessary to drop skid plate
to reach stud nuts (fig. 37).) Transmission can now be shifted on its
mounting base by means of adjusting screw, head of which protrudes
through notch of frame fitting, located at rear of transmission (fig.
38).
[Illustration: RA PD 310233
_Figure 36—Front Chain Inspection Hole Cover Removed_]
(4) Turn adjusting screw clockwise (to the right) to move transmission
backward and tighten front chain. Turn adjusting screw counterclockwise
(to the left) to move transmission forward and loosen front chain.
(5) After moving transmission by means of adjusting screw, check front
chain adjustment; then securely tighten the three transmission mounting
stud nuts and again check chain adjustment, as tightening stud nuts
sometimes changes chain adjustment.
(6) After front chain adjustment has been made, securely tighten the
three transmission mounting stud nuts.
(7) Install front chain inspection hole cover and tighten screws.
(8) Check shifter lever control linkage adjustment (par. 54).
(9) Check clutch control linkage adjustment (par. 48).
[Illustration: RA PD 310234
_Figure 37—Skid Plate Dropped to Show Location of Transmission
Mounting Nuts_]
[Illustration: RA PD 310235
_Figure 38—Transmission Mounting Nuts and Chain Adjusting Screw_]
60. ADJUST REAR CHAIN AND ALINE REAR WHEEL (fig. 39).
=a.= In moving transmission backward on its mounting to tighten
front chain, the rear chain will be loosened. Rear chain must then
be adjusted by moving rear wheel backward. When rear wheel is moved
either forward or backward, adjustment of the rear wheel brake is
affected.
=b.= When checking rear chain for slack midway between the sprockets,
turn wheel and rotate chain to position of least slack. Use free
up‐and‐down movement of finger to lift chain and depress it to
determine tightest position.
[Illustration: RA PD 310236
_Figure 39—Brake Sleeve Nut_]
=c.= At position of least slack, a correctly adjusted rear chain has
1/2-inch, or slightly more, free up‐and‐down movement midway between
sprockets. Chain must never be run taut (no slack at tightest point).
Chain must never be allowed to run loose enough to cause jerky
operation and/or strike the chain guard or other chassis parts.
=d.= At the time rear chain adjustment is made, inspect chain for
correct lubrication and if necessary, adjust rear chain oiler (par. 61).
=e.= Rear chain adjustment and rear wheel alinement are both made by
means of the rear wheel adjusting screws. Therefore, adjustment of
either the chain or the wheel alinement can affect adjustment of the
other, making it necessary to consider both adjustments at the same
time.
(1) Remove rear axle nut and lock washer (right side of vehicle).
(2) Loosen brake sleeve nut enough to allow brake assembly to slide
backward or forward in frame mounting (fig. 39).
(3) Loosen the two (right and left side) rear wheel adjusting screw
lock nuts.
(4) Turn wheel adjusting screws clockwise (to right) to move wheel and
sprocket backward. This tightens chain. NOTE: _If chain is too tight,
turn wheel adjusting screws counterclockwise (to left) so that wheel
can be shifted forward. This will loosen chain._ Always turn the two
wheel adjusting screws an equal number of turns in order to keep wheel
alined.
(5) Check correct alinement of wheel by noting that tire (not tire
rim) runs approximately midway between lower rear frame tubes at the
point where tubes join transmission mounting. It is desirable to have
tire run slightly closer (not more than 1/16 in.) to right than to
left side lower tube. A further check of alinement is observing that
rear sprocket runs centrally in chain. CAUTION: _If rear wheel is not
correctly alined, vehicle steering will be affected, and sprockets will
wear excessively on one side._
(6) With adjustment of chain and wheel alinement completed, securely
tighten wheel adjusting screw lock nuts, and brake sleeve nut: replace
axle lock washer and nut, tightening nut.
(7) Recheck adjustment of chain as tightening brake sleeve nut and axle
nut sometimes changes the chain adjustment.
(8) After tightening rear chain, rear brake may be found too tight.
Check and correct brake adjustment (par. 96).
=61. CHAIN OILERS= (fig. 40).
=a.= Both front and rear chains are automatically lubricated by
engine oil pumps. Chain oilers are adjustable and may need occasional
readjustment to meet lubrication requirements of varied operating
conditions. Chains under most operating conditions require a very small
amount of oil; therefore, chain oilers require very fine adjustment to
supply just enough oil without waste.
=b.= When adjusting chain oilers, it is advisable to add or remove only
one thin washer at a time and inspect chain again after vehicle has run
approximately 100 miles, to determine whether or not further adjustment
is necessary.
=c.= If inspection of front chain through inspection hole reveals that
chain is not getting enough oil, adjust front chain oiler as follows:
(1) Add thin (0.002-inch thick) washer under head of front chain oiler
adjusting screw (fig. 40). Do not remove any washers already under head
of screw.
(2) To check results, refer to step =b= above.
=d.= Evidence of too much oil on front chain requires cutting down on
chain oiler.
[Illustration: RA PD 310237
_Figure 40—Chain Oilers_]
(1) To adjust oiler, remove thin (0.002-inch thick) washer from under
head of front chain oiler adjusting screw (fig. 40).
(2) To check results, refer to step =b= above.
=e.= If inspection reveals that rear chain is not getting enough oil,
and that oil pipe end is open, is not bent, and is directed on chain;
then the rear chain oiler must be adjusted.
(1) Adjust oiler by adding thin (0.002-inch thick) washer under head of
rear chain oiler adjusting screw (fig. 40). Do not remove any washers
already under head of screw.
(2) To check results, refer to step =b= above.
=f.= Evidence of too much oil on rear chain (supplied by oiler)
requires cutting down on chain oiler.
(1) To adjust oiler, remove thin (0.002-inch thick) washer from under
head of rear chain oiler adjusting screw (fig. 40).
(2) To check results, refer to step =b= above.
=g.= At 1000-mile intervals, loosen both front and rear chain oiler
adjusting screws (fig. 40) two turns each. Do not remove screws. Start
and idle engine 1 minute, then tighten screws firmly, but do not force.
This operation serves to flush oiler control valves and rear chain
oiler pipe.
62. REPLACEMENT OF FRONT CHAIN.
=a.= A new or original duplex front chain is endless, not provided with
connecting link, and engine sprocket must be removed in order to remove
or replace chain.
=b. Remove.=
(1) Remove outer front chain guard (par. 102).
(2) Remove engine sprocket (par. 65). Chain can now be lifted off
clutch sprocket.
=c. Install.= When installing a new front chain and/or sprocket, it
may be necessary to shift transmission ahead in order to get chain on
(par. 59 e).
(1) Clean engine shaft taper and sprocket hole.
(2) Place chain on clutch sprocket teeth and install sprocket (par. 65).
(3) Check chain adjustment (par. 59).
(4) Install outer front chain guard (par. 102).
63. REPLACEMENT OF REAR CHAIN (fig. 41).
=a. Remove.= Support vehicle on rear stand. With transmission in “N”
(neutral) position, turn rear wheel until chain connecting link is
located on rear sprocket teeth, about straight back from axle.
(1) Using pliers, lift split end of connecting link spring clip out of
link pin notch, taking care not to damage spring clip. Remove spring
clip from other link pin notch.
(2) Pull off link side plate and push link out of chain ends. Replace
connecting link and spring clip in one end of chain to prevent its loss.
[Illustration: RA PD 310238
_Figure 41—Rear Drive Chain and Connecting Link_]
(3) Pull on lower half of chain, guiding upper part while it rotates
around countershaft sprocket, until removed. If a new rear chain is to
be installed, one end can be linked to the upper half end of old chain
and can be pulled onto countershaft sprocket as old chain is removed.
=b. Install.= When installing a new rear chain and/or countershaft
sprocket, it may be necessary to set rear wheel ahead in order to get
chain on (par. 60).
(1) Start end of chain over countershaft sprocket teeth, using starter
crank to turn sprocket. After chain end has reached front half of
sprocket, it will be necessary to guide end under sprocket and out of
sprocket cover. Center chain so that ends engage rear sprocket teeth,
back of the axle.
(2) Install connecting link, side plate and spring clip. See that open
end of spring clip is to the rear with regard to chain travel (like the
end of an arrow). If original spring clip is bent or damaged, use a new
one.
(3) Adjust rear chain (par. 60).
(4) Check rear brake adjustment (par. 96).
=64. CHAIN REPAIR TOOL= (fig 42).
=a.= Damaged or broken chain links can be replaced with connecting
(repair) links after bad links have been removed. To remove damaged
or broken link, push out chain side plate pins with the chain repair
tool (41-T-3320). Front chain is a double row of duplex chain; rear
chain is a single row chain. The chain tool furnished in the tool kit
is designed to accommodate both. To put a connecting link in the front
chain, it will be necessary to remove front chain guard (par. 102).
[Illustration: RA PD 310239
_Figure 42—Chain Repair Tool in Use_]
=b.= When connecting (repair) links have been fitted to chain, make
sure that spring clips are correctly and securely locked on link pin
ends.
65. REPLACEMENT OF ENGINE SPROCKET.
=a. Remove.=
(1) Remove front outer chain guard (par. 102).
(2) Remove engine sprocket nut (right‐hand thread). It will be
necessary to strike wrench with a hammer to loosen nut.
(3) Give flat surface of engine sprocket, near outer edge, a light
but sharp rap with a hammer, being careful not to strike and damage
sprocket teeth. Take care not to lose sprocket shaft key.
=b. Install.= If new sprocket is being installed, it may be necessary
to shift transmission forward to get chain to fit on sprockets (par.
59).
(1) Thoroughly clean engine shaft taper and see that key is in place.
Clean sprocket taper hole, fit front chain on sprocket teeth, and
rotate chain until keyway in sprocket lines up with key in engine
shaft. Slip sprocket onto engine shaft, install nut, and tighten
securely. Strike wrench with a hammer to make sure sprocket nut is very
tight.
(2) Install front outer chain guard (par. 102).
66. REPLACEMENT OF COUNTERSHAFT SPROCKET.
=a. Remove.=
(1) Remove foot starter crank (par. 55).
(2) Remove starter crank spring (par. 56).
(3) Remove countershaft sprocket cover (par. 52).
(4) Bend back extension of sprocket nut lock.
(5) Remove sprocket retaining nut. It will be necessary to strike
wrench with a hammer to loosen nut.
(6) Give sprocket a light but sharp rap with a hammer near outer edge,
being careful not to strike the sprocket teeth, and remove sprocket
from shaft taper. Do not lose the two sprocket shaft keys.
=b. Install.=
(1) Clean shaft taper and taper hole in countershaft sprocket. Install
the two keys.
(2) Install sprocket on shaft. Place rear chain on sprocket before
installing sprocket cover.
(3) Examine nut lock and, if badly damaged, use a new one.
(4) Install sprocket retaining nut. Tighten by striking wrench with a
hammer. NOTE: _This nut must be tight._ Bend up extension of nut lock
against side of nut.
(5) It will be easier to install starter crank spring at this step to
avoid interference with sprocket cover.
(6) Install sprocket cover.
(7) Install starter crank.