B&M 70226 TRANSKIT FOR GM 4L80E TRANSMISSION - Manual (Page 3)

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Be careful with the internal and exter-
nal wiring harness. Wiring and/or con-
nectors are easily damaged and diffi-
cult to troubleshoot if they are dam-
aged.
VERY IMPORTANT
Use petroleum jelly to hold checkballs
and gaskets in place during installa-
tion. DO NOT use any kind of wheel
bearing grease to hold checkballs in
place, these greases do not melt or
mix readily with ATF and can block shift
and pressure control solenoid feed cir-
cuit filters and orifices, causing erratic
shifts and potentially serious transmis-
sion damage because of low line pres-
sure.
CAUTIONS ABOUT PCM.
The MIL (Malfunction Indicator Light or
Check Engine Light) may be illumi-
nated (turned ON) if the vehicle is
started and any of the transmission
electrical connectors are disconnected
or has wires that are broken, or have
been pinched and/or shorted. The MIL
is programmed to illuminate whenever
a system (engine or transmission)
component malfunctions and at the
same time a DTC (Diagnostic Trouble
Code) is set in the PCM. You may have
to refer to your owners manual, a GM
service manual or visit a GM dealer to
determine the source of the
malfunction(s) that cause(d) any DTC
codes to be set and the required rem-
edy. Make sure your engine is in good
tune and any problems related to set
trouble codes are repaired BEFORE
attempting to install your B&M
Transpak Kit.
Do Not attempt to jumper the Data Link
connector to read a DTC from the PCM
in your vehicle until you have checked
your owners manual, GM service
manual, or verified with your GM dealer
that the particular PCM in your vehicle
allows jumpering the data link.
Jumpering the data link connector to
read DTC’s is not possible on any 1996
or later OBD II vehicle and can dam-
age the PCM and result in a very ex-
pensive repair bill. Except for some
1991 to 1995 PCM’s, all others will re-
quire the use of a diagnostic scanner
to read. Some DTC codes are “hard
codes” and may require a diagnostic
scanner to turn them off after the mal-
function which set the DTC has been
repaired.
If electrical power to the transmission
is cut or the PCM fails the 4L80E will
operate in “limp home” mode. If this
happens, you will only have Reverse
and Drive 2 range available.
Before installing your Shift Improver Kit
there are several other B&M products
you may wish to consider and are
available at your B&M dealer:
- TRICK SHIFT PERFORMANCE
ATF: The industry’s only real perfor-
mance ATF. A specially blended oil
formulated with foam inhibitors, ex-
treme pressure agents and shift im-
provers, this fluid assures protection
while delivering the fastest possible
shifts. You literally “Pour in perfor-
mance”.
- TRANSMISSION OIL COOLER:
We feel that it is very important that
every vehicle used in heavy duty or high
performance application should have
an auxiliary oil cooler. Excessive heat
is the primary cause of transmission
failures, and an auxiliary oil cooler is
an inexpensive safeguard against over-
heating and failure. B&M offers a wide
range of transmission coolers to suit
every need.
- DRAIN PLUG KIT (P/N: 80250):
1991 and early 1992 model 4L80E
transmission oil pans do not come from
the factory equipped with drain plugs.
The B&M Drain plug kit is inexpensive
and easy to install. It eliminates the
mess when changing fluid or on pan
removal.
- TEMPERATURE GAUGE KIT (P/N:
80212): Most transmission and con-
verter failures can be traced directly
to excessive heat. The B&M transmis-
sion temperature gauge can save you
a costly repair bill by warning you of
an overheated transmission. The B&M
temperature gauge comes with all nec-
essary hardware and is easy to install.
PREPARATION FOR KIT
INSTALLATION
Automatic transmissions operate at
temperatures in the range of 150° and
250° Fahrenheit. We recommend the
vehicle be allowed to cool for several
hours before disassembly to avoid
burns from hot oil and parts. The ve-
hicle 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.
Have an oil drain pan ready to catch
oil and a tray on which to put small
parts so they won’t get lost.
It can never be said enough: Make sure
you have a clean, dust free place to
work. Burrs and dirt are the number
one enemies of an automatic trans-
mission. Contamination in the valve
body or pressure regulator valve train
can result in serious transmission dam-
age and un-predictable operation.
Transmission components are preci-
sion fit. Work slowly and do not force
any parts.
This kit contains all parts necessary
to obtain two different shift feel levels
of performance depending on the in-
tended use:
1. Heavy Duty level: Towing, camp-
ers and, 4-wheel drive vehicles. Shift
feel is firm and positive.
2. High Performance Street level:
Dual purpose performance vehicles.
High Performance Street level pro-
duces the firmest shift feel.
DISASSEMBLY
STEP 1. Position your drain pan un-
der the transmission to catch the
ATF.Remove oil pan by first removing
rear pan bolts, then work towards the
front. Loosen but do not remove the
three front bolts. If the pan sticks to
the gasket, insert a flat screwdriver be-
tween the pan and case and pry down
gently to break pan loose. Now slowly
back out the front three bolts to per-
mit draining the ATF. Remove pan gas-
ket and inspect for damage. The Oil
Pan Gasket is reusable (if not dam-
aged) except on 1991 and early ‘92
transmissions. An Oil Pan Gasket
IS NOT included with this kit. If your
gasket is damaged, ypu will have to
purchase one at your parts supplier.
STEP 2. Remove the oil filter from
case by gripping it firmly and pulling it
straight out away from the case. In-
spect the filter pickup tube seal that
is pressed into the pump housing (See
Fig. 1). If the seal and filter appear to
be in good condition they may be re-
used, otherwise both the seal and fil-
ter should be replaced.
STEP 3. There are several different wir-
ing harness configurations used on the
4L80E. Before proceeding further,
make a sketch and some notes de-
scribing your particular unit, recording
TM