B&M 20261 SHIFT IMPROVER KIT - Manual (Page 3)

Detent spring
Manual
linkage
Governor
tubes
Manual
valve
Vacuum modulator
Detent solenoid
Figure 4
Governor tubes
When removing valve body be sure not to allow
manual valve to fall out and be damaged
Figure 5
3
We suggest a clean work bench from
which oil can be easily cleaned or a
large clean piece of cardboard could
also work.
This kit contains all the parts nec-
essary to obtain two different levels of
performance, depending on the vehicles
intended use:
1. Heavy Duty; Towing, campers, motor
homes and 4-wheel drive vehicles.
Heavy Duty level is a good starting
place for light weight, high powered
vehicles such as street rods. Heavy
duty level produces firm noticeable
shifts.
2. Street; Dual purpose performance
vehicles, street and strip performance
cars and, off road vehicles. Street level
produces very firm, positive shifts.
DISASSEMBLY
Automatic transmissions operate
at temperatures between 180 0 F and
240 0 F. We recommend that the vehicle
be allowed to cool for several hours
before attempting disassembly to avoid
serious burns from hot oil and parts.
The vehicle should be raised so there is
at least 2 feet ground clearance for
ease of installation and safety.
MAKE SURE THE VEHICLE IS RIG-
IDLY AND SECURELY SUPPORTED,
JACK STANDS, WHEEL RAMPS OR
A HOIST WORK BEST, DO NOT USE
JACKS ALONE.
STEP 1. Have an oil drain pan ready
to catch oil and a clean tray on which
to put small parts so they won’t get lost
or dirty. Drain the oil by removing the
rear pan bolts and work towards the
front leaving the two front bolts in place.
If the pan is stuck to the case pry the
pan loose with a screw driver. Slowly
remove the remaining two front bolts
allowing the rest of the fluid to drain.
STEP 2. Oil filter removal (See Fig.
3): Remove the shoulder bolt holding
the filter then pull the filter straight
down. Some models also use a spacer
between the filter and valve body. Watch
out for oil splatter. If the oil pick-up tube
did not come out with the filter, pull it
out. Remove the O-ring from the bore
in the case if it did not come out with
the oil pick-up tube. Be careful not to
scratch the case bore when removing
the O-ring.
STEP 3. Observe the location of the
following (See Fig. 4) Manual linkage,
detent spring with roller and the way
the internal shift lever pin engages the
manual valve in the valve body, gover-
nor tubes and their routing, detent so-
lenoid (oval or square can) and its wire
connector, white spark control switch
wire and routing of the wire.
STEP 4. There are (3) 1/4-20 and (8)
5/16-18 bolts holding the valve body.
Remove all but one valve body bolt and disconnect the spark control switch
wire if present. Hold the valve body in
place and remove the last bolt. Lower
the valve body while at the same time
pulling straight down on the governor
tubes (See Fig. 5). Place the valve
body in the oil pan to avoid contamina-
tion. NOTE: The front servo may fall out
of the case, if it does see Figure 6 for
reassembly order. Use grease or pe-
troleum jelly to hold the servo compo-
White smog
switch wire
Manual
linkage
pin