B&M 50442 TORK MASTER 3000 C4 26 SPLINE 10.5 - Manual (Page 6)

high idle speed requirements indicate
poor bottom-end torque characteris-
tics which will need to be corrected
to obtain maximum converter perfor-
mance.
Modified torque converters are installed
to improve performance and durability
not available from a stock torque con-
verter. Heavy Duty and racing applica-
tions impose higher loads and greater
heat dissipation than stock operating
conditions.
Oil Cooling: The factory heat ex-
changer is usually inadequate for Heavy
Duty and/or Racing applications. The
following B&M Oil Coolers are recom-
mended for performance applications.
Heat is the major enemy of automatic
transmissions and a cooler will also
prolong the life of your transmission.
B&M will not warranty torque convert-
ers which show heat damage from mis-
use or inadequate cooling.
B&M
Part No. Rating/Application
70255 16,000 GVW Street perfomance
70268 19,000 GVW Campers, small
motor homes, high stall converters
70264 24,000 GVW Large motor homes,
towing, high stall converters
70266 28,000 GVW Road & off-road race
cars (high flow race cooler)
Driving Techniques:
Traveler:
Traveler torque converters should
be driven like a stock torque converter.
Stall speeds and converter slip will
coincide with torque demand and ad-
just automatically. Additional decel-
eration will be noticed during manual
downshifts.
Holeshot and TorkMaster:
Holeshot and TorkMaster torque con-
verters are designed for street perfor-
mance and should not be considered
as a low cost race converter. Under
normal driving conditions Holeshot and
TorkMaster torque converters will func-
tion like stock converters with some
additional slip. High stall speeds are
available at torque demand. The best
standing start acceleration performance
is usually obtained by “stalling” the
converter at 1500-2000 rpm with the
brakes locked just prior to launching
the car. Bang the throttle and release
the brake pedal at the instant of launch.
Marginal traction situations may re-
quire you to “drive the car out” or feel for
traction with the gas pedal as you leave
the starting line. Remember, Holeshot
and TorkMaster torque converters are
designed for street performance and
occasional drag strip use. Race cars
need Race converters.
Maintenance:
Street Use: Change fluid and filter
every 10,000 - 12,000 miles. This will
also help the life of the transmission.
Check torque converter bolts or nuts
every 20,000 - 24,000 miles.
Ballooning: Ballooning is expansion
of the torque converter along the axis of
rotation (front to back). This is caused
by high rpm use and/or continuous
wide open throttle stall speeds. A
ballooned converter can lose thrust
washer piloting and must be cut open
for repair. You can check for ballooning
by measuring the end play clearance of
the stator and turbine. (See Fig. 8) You
will have to make a hooked tool to grab
the stator or turbine. (See Fig. 9) Maxi-
mum stator or turbine end play is .050
inch. If stator or turbine end play
exceeds .050 inch the converter will
have to be cut open to repair the cover.
Cracks and Leaks:
Leaks can be caused by several
reasons. The most common are front
seal failure and vibration cracks.
Front seal failure is due to improp-
erly installed seal (damaged during in-
stallation), misalignment, worn pump
bushing, or worn converter impeller hub.
A ballooned converter can have a slightly
bent impeller hub. Inspect the pump
bushing when you replace the seal.
Check dowel pins in the engine block
for sufficient engagement and polish
the converter impeller hub with 400 grit
wet and dry sandpaper and oil.
Cracks can develop in the impeller
hub or perimeter weld from stress and
vibration. If a crack occurs around the
impeller or pilot hub we recommend
you return it for repair.
Measure end play
by hooking the
tool to the stator and
lifting up and down
Figure 8 Figure 9
12"
Typical homemade tool
used to check torque
converter end play