B&M 70244 CONVERTER LOCKUP CNTRL - Manual (Page 3)

verter Lock-Up Control through the
brake switch as a safety precaution.
The brake switch disengages the lock-
up clutch upon brake application in the
unlikely event of an electrical malfunc-
tion. Route wires next to members
where they can be secured. Once again
remember to avoid mechanisms and
hot pipes which can fray or melt the
insulation and cause a short circuit.
OPERATION
Operation of your B&M Converter Lock-
Up Control is automatic once it has
been preset to the desired lock-up speed.
When properly connected the Red LED
on the front of the Converter Lock-Up
Control should light when the ignition
key is turned on (if it does not, please
recheck the Red & Black wires). Lock-
up engagement speed is adjusted while
operating the vehicle. Operate the ve-
hicle at the speed where you want the
lock-up to be engaged continuously.
Turn the knob until the Green LED lights
and the converter clutch lock-up occurs.
The lock-up engagement speed can be
changed at any time to suit driving con-
ditions by turning the knob left or right as
desired.
CUSTOM TRANSMISSION
INSTALLATION
B&M’s Converter Lock-Up Control is
especially suited for controlling the lock-
up clutch in vehicles with custom trans-
mission installations which were not
originally manufactured with a torque
converter clutch equipped transmission.
Custom transmission installations uti-
lizing early model transmissions with
valve body controlled lock-up (TH-200-
4R, TH-700-R4) speed may require
some modification to operate correctly.
In these cases consult the appropriate
factory service manual to locate the
converter clutch shift valve train in the
valve body. Deactivate the converter
clutch shift valve by removing the spring
holding the valve train in the OFF posi-
tion. This will allow the converter clutch
shift valve to move to the ON position
and ensure that control pressure is
always available at the converter clutch
apply valve after the first gear shift. A
TH-700 converter clutch shift valve train
is shown in Figure 2 as an example.
It may also be necessary to remove the
oil pan and identify which kind of solenoid
and wiring scheme is used on your
3
particular unit. A prewired four pin trans-
mission connector (attached to the Con-
verter Lock-Up Control module) is pro-
vided for these applications.
LOCK-UP CLUTCH AND SOLENOID
BASICS
The lock-up clutch is located inside the
torque converter and is designed to
eliminate torque converter slip for im-
proved efficiency. In GM vehicle’s the
speed at which lock-up clutch engage-
ment occurs is controlled either by
hydraulic circuits inside the transmis-
sion or by the vehicles Electronic Con-
trol Unit (ECU). Lock-up clutch en-
gagement occurs when the Converter
Clutch Apply Valve changes position
and vents the area behind the lock-up
clutch piston. The converter clutch ap-
ply valve’s position (on/off) is deter-
mined by the converter clutch solenoid
and the availability of control pressure.
In most early applications the solenoid
is always energized and control pres-
sure is supplied by a shift valve in the
valve body which determined at what
speed lock-up occurred. Later applica-
tions eliminated the shift valve alto-
gether and supply control pressure
Figure 2
ECU controlled TCC
have these
Remove spring if
present
TH-700-R4 valve body TCC valve train
NOTE: TCC valve train and bore are not
present beginning 1989 model year