B&M 20261 SHIFT IMPROVER KIT User Manual
Page 6

6
Install two furnished O-rings on
pickup tube. Lubricate throughly
with oil before installation.
Figure 12
TROUBLE SHOOTING GUIDE
Malfunction
Probable Cause
Slips
Valve body bolts loose.
Low fluid level.
Overheating
Insufficient cooler capacity
clogged lines or cooler.
Foaming oil at dipstick
Fluid level too high.
or breather
Clogged lines or cooler.
Erratic shifting
Vacuum line cracked or leaking.
Shifter not properly adjusted.
Kickdown switch not properly adjusted.
Low fluid level.
High fluid level.
Valve body bolts loose.
Kickdown solenoid loose.
Late hard shifts
Vacuum line cracked or leaking.
Kickdown solenoid loose or damaged.
Kickdown solenoid gasket damaged.
Will not shift
Kickdown solenoid loose or damaged.
Governor tubes not properly installed.
Pump buzz or whine
Low fluid level.
High fluid level.
Cut, damaged or missing pick-up tube O-rings.
shift transmission through all gears.
Place selector in neutral and check the
fluid level. It should be between the
Add and Full marks. Do not overfill !!
This can cause foaming and overheat-
ing. Turn off engine and lower vehicle.
STEP 18. Drive vehicle several miles to
warm up the transmission. Park on
level surface and check ATF level. It
should be between Add and Full.
TOOL LIST
1
3/8" drive ratchet or speed
handle
1
1/2" socket, 3/8" drive
1
7/16" socket, 3/8" drive
1
Small flat screwdriver
1
Small Internal Snap Ring
Pliers
1
Small Hammer
1
Torque Wrench 0-10 lb.ft.
(0-13.6 Nm)
1
1/4" Drill Motor
1
Vise
TH-400/TH-475 (3L80/3L80-
HD) SHIFT IMPROVER KIT
PARTS LIST
Inspect the contents of your Shift
Improver Kit carefully. If you are miss-
ing any of the parts shown below, do
not proceed. Contact your B&M
dealer. Don’t forget to purchase about
5 quarts of ATF (See Step 17).
1
20261 Instructions
1
Seperator Plate
1
Oil Pan Gasket
1
5/32" Drill
1
Seperator Plate/Case
Gasket
1
Valve Body/Case Gasket
2
Filter Pick Up Tube O-Ring