B&M 70248 CONVERTER LOCKUP CNTRL User Manual

Converter lock-up control, Nstallation instructions

NOTE: This kit is designed for trans-
missions equipped with an original
equipment electronic speed sensor.
This kit does not work with electroni-
cally controlled transmissions or
transaxles (4L60E, 4L80E, 4T60E,
4T80E, etc.). Use kit P/N 70244 for
transmissions equipped with a me-
chanically driven speedometer cable.

INTRODUCTION

Please read the instruction sheet thor-
oughly before attempting to install your
B&M Converter Lock-Up Control.
B&M’s Converter Lock-Up Control
provides driver control of the speed
where converter clutch lock-up takes
place. This dash mounted electronic
control module has a dial to adjust
lock-up speed, a two color LED (Light
Emitting Diode) that indicates the lock-
up clutch status and a power on/off
button. The Converter Lock-Up Con-
trol module receives a signal from the
transmission mounted speed sensor.
This signal along with the dial setting
determines the precise speed at which
to activate the lock-up clutch solenoid.
Whenever the ignition is on and power
button is engaged but the vehicle is
stopped or moving slowly the LED is
RED (lock-up clutch off). When the
vehicle reaches the speed preset by
the dial on the Converter Lock-Up
Control module, the LED turns
GREEN and power is available to the

lock-up clutch solenoid. This will acti-
vate the solenoid and cause the con-
verter clutch to lock-up. Once the trans-
mission has shifted beyond first gear
and the solenoid is activated, lock-up
will occur at any speed within the range
of the Lock-Up Control. B&M’s Con-
verter Lock-Up Control will not cure
a defective converter clutch, however
if the clutch is not defective the B&M
Converter Lock-Up Control will lock
it at the preset speed.
WARNING: When using B&M’s Con-
verter Lock-Up Control with any four
speed overdrive transmission, we rec-
ommend that lock-up speed not be set
higher than 45 M.P.H.. Operation in
fourth gear (Overdrive) without the
converter clutch locked-up can result
in transmission and engine overheat-
ing.

PREINSTALLATION

Before installing your B&M Converter
Lock-Up Control we recommend that
you perform a few simple transmis-
sion performance checks and make
sure you have certain tools and equip-
ment on hand to assist in the installa-
tion.

LOCK-UP CLUTCH OPERATION

Operate vehicle with range selector in
third gear (Drive) position. Choose an
area where you will not exceed the

local speed limit. Verify proper opera-
tion of lock-up clutch and transmis-
sion. Accelerate the vehicle at low
speed until it shifts into third gear.
Lock-up clutch operation (in stock ve-
hicles) can usually be checked by
operating the vehicle at a steady speed
and lightly depressing the brake pedal
just enough to activate the brake light
switch. Alternatively, depress the
throttle a small amount but rapidly,
this should cause the lock-up clutch to
disengage, then rapidly return throttle
to steady speed position and lock-up
clutch should reengage. When the
lock-up clutch engages and disen-
gages you should notice a 200-500
RPM change in engine speed. If the
lock-up clutch is defective replace the
torque converter.

TRANSMISSION PERFORMANCE

Check overall transmission perfor-
mance for shift quality and timing. If
performance seems sluggish or shift
timing is occurring too early or late
check vacuum lines and transmission
throttle valve or detent cable adjust-
ment. Check transmission oil pres-
sures and compare them to the appro-
priate service manual for your vehicle.
If the problems persist B&M has a
complete line of products for rebuild-
ing and enhancing the performance of
General Motors Transmissions.

9500540-04

Printed in the U.S.A.

Not legal for sale or use on pollution controlled motor vehicles.

nstallation Instructions

Converter Lock-Up Control

TH700-R4/4L60, 200-4R

Part Number 70248