1967 CHEVROLET CAMARO service indicator

ENGINE-ELECTRICAL 6Y-J2

Fig.
8c—Ammeter Method Test Connections

10.
Turn off ignition, disconnect battery ground cable,

and remove all test equipment.

11.
li the Delcotron meets the test specifications, the

problem is not in the generator.

12.
Ti the Delcotron fails to meet the test specifications,

remove it and perform bench tests and make repair

needed.

DELCOTRON DIODE AND FIELD TEST (Fig. 9c)

NOTE:
These tests will indicate good,, shorted

or open field or shorted diode but will not indi-

cate a failed open diode. If output was low and

following tests show good, refer to service op-

erations to determine cause and repair.

1.
Disconnect battery ground cable at battery.

2.
Positive diodes (Test A) connect an ohmmeter be-

tween "R" terminal and "BAT" terminal and note

Fig.
9c-Deicotron Diode and Field Test
reading, then reverse the leads at same terminals

and note this reading. Meter should read high re-

sistance in one direction and low in the other.

3.
Negative diodes (Test B) connect ohmmeter between

"R" terminal and "GRD" and note reading, then

reverse the leads and note this reading. Meter

should read high in one direction and low in the

other.

NOTE:
A high or low reading in both directions

indicates a defective diode.

4.
Open Field Check:

a. Connect an ohmmeter from "F" terminal to

"GRD"
terminal stud and note reading on the

lowest range scale. Meter should read 7 to

20 ohms.

b.
If meter reads zero or excessively high resist-

ance, the Delcotron is faulty.

5. If above tests indicate a defective Delcotron, remove

and completely check Delcotron as outlined under

''Service Operations".

INDICATOR LAMP/INITIAL FIELD

EXCITATION CIRCUIT TESTS (Fig. 10c)

On standard models the indicator lamp circuit provides

initial field excitation (causing lamp to glow). The light

is cancelled by closing the field relay which applies bat-

tery voltage to both sides of bulb (bulb goes out).

The indicator light should glow when ignition switch is

"ON"
and go out almost immediately when engine starts.

Ammeter equipped vehicles use the same initial field

excitation and control circuits as the indicator lamp ex-

cept the lamp is omitted. The continuity tests on both

type vehicles can be made as follows:

If Lamp Fails to Glow or Ammeter Fails to

Function the Possible Causes are:

1.
Faulty bulb or bulb socket.

2.
Faulty ammeter.

3.
An open circuit in wiring, regulator, or field.

4.
A shorted positive diode—(may also cause glow with

ignition switch "OFF").

TEST AS FOLLOWS:

1.
Disconnect connector from regulator and turn

ignition switch to "ON". Connect a test lamp from

connector terminal "4" to ground (fig. 10c, Step 1)

and note test lamp.

a. Lamp fails to glow—check for faulty bulb, socket

or open circuit between switch and regulator con-

nector. Repair as needed.

b.
Light goes on—failure is in regulator, Delcotron,

or wire between "F" terminals on regulator and

Delcotron. Go to Step 2.

2.
Disconnect lamp lead at ground end and connect be-

tween connector "F" and "4" terminals (fig. 10c,

Step 2), and note lamp:

a. Test Lamp glows—problem is in regulator. An

open circuit in regulator or relay is stuck dosed.

See "Service Operations" for repair.

b.
Fails to glow—problem is in wire between "F"

terminals on generator and regulator or infield

windings. Go to Step 3.

3.
Disconnect test lamp at connector "F" terminal and

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-15

L
RELAY

TERMINAL "F" TERMINAL

"BAT" \ ' /

TERMINAL
/ / /
GRD7
TERMINAL

5.5" SERIES ID DELCOTRON
"BAH"

TERMINAL

^Vs^^^^lijBii^^8C^3^SH|j^^^^^^sH^^Bf- y/

RELAY ^^^"^^^jWwIi^^^^ RELAY

6.2" SERIES 2D, TYPE 150 DELCOTRON

Fig.
14c—Delcotrons - Full View

end or use Adapter J-21501 and a box wrench) on re-

taining nut, insert a 5/16" alien wrench through

socket and adapter into hex on shaft to hold the shaft

while removing the nut.

2.
Remove washer and slide pulley from shaft.

3.
To install, slide pulley and washer on shaft and start

the nut.

4.
Use the socket and adapter with a torque wrench and

tighten-nut to 50 ft. lbs. torque.

BRUSH
REPLACEMENT

6.2"
Delcotron

1.
Remove two nuts retaining the blade connectors and
remove the connectors (fig. 17c). Slide the indicator

light relay wire from the terminal post.

2.
Remove two screws retaining the capacitor and brush

holder to rear end frame, Remove brush holder.

3.
To install brushes, push brushes into holder and

install pin to keep the brushes in holder.

4.
Attach brush assembly and condenser to the end

frame with hex-head stud on the .left side only.

Fig.
15c—Pulley Removal

Fig.
16c—Torqulng Pulley Nut

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-24

is at the full mark on the dip stick, it is just slightly be-

low the planetary gear unit. If additional oil is added,

bringing the oil level above the full mark, the planetary

unit will run in the oil, foaming and aerating the oil. This

aerated oil carried through the various oil pressure pas-

sages (low servo, reverse servo, clutch apply, converter,

etc.) may cause malfunction of the transmission assem-

bly, resulting in cavitation noise in the converter and

improper band or clutch application. Overheating may

also occur.

If the transmission is found consistently low on oil, a

thorough inspection should be made to find and correct

all external oil leaks.

PERIODIC OIL CHANGE

The transmission oil should be changed periodically as

recommended in Section 0, and whenever transmission is

to be removed from the vehicle for repairs.

1.
Run engine for one minute in neutral prior to chang-

ing.

2.
Be sure vehicle is level or raise from the rear only.

3.
Remove the oil pan drain plug and allow oil to drain

thoroughly into a pan or can.

Replace drain plug and refill with approximately two

quarts of oil specified in Section 0.

NOTE: To refill the transmission, remove dip

stick from oil filler tube and refill transmission

with oil specified in Section 0 using filler tube

and funnel J-4264. Then, after shifting into all

ranges at idle speed to fill all oil passages, the

engine should be run at 800-1000 rpm with the

transmission in Neutral until the oil warms up,

then add oil as required to raise the fluid level

to the full mark on the dip stick. Refill capacity

is approximately 2 qts.
4.

Fig.
1PG - Adjusting Low Band Using J-21848
PERIODIC LOW BAND ADJUSTMENT (Fig. 1PG)

Low band adjustment should be periodically performed

at 12,000 mile intervals, or sooner, as necessary if op-

erating performance indicates low band slippage.

1.
Raise vehicle and place selector lever in neutral.

2.
Remove protective cap from transmission adjusting

screw.

3.
a. On Corvette Models: Drop left exhaust pipe for

clearance.

b.
On Chevelle Models: To gain clearance between

underbody and transmission, it may be necessary

to remove rear mount bolts from crossmember,

and move transmission slightly toward passenger

side of vehicle. .

4.
Loosen adjusting screw lock nut 1/4 turn and hold in

this position with wrench.

5.
Using Special Tool J-21848 adjust band to 70 in. lbs.

and back off four (4) complete turns for a band which

has been in operation for 6,000 miles or more,.or

three (3) turns for one in use less than 6,000 miles.

CAUTION: Be sure to hold the adjusting screw

lock nut at 1/4 turn loose with a wrench during"

the.adjusting procedure.

6. Tighten the adjusting screw lock nut to specified

torque.

CAUTION: The amount of back-off is not an

approximate figure, it must be exact.

MANUAL SHIFT LINKAGE CHECK & ADJUST

(Column Type)

1.
The shift tube and lever assembly must be free in the

mast jacket. See Section 9 for alignment of steering

column assembly if necessary.

2.
To check for proper shift linkage adjustment, lift

the transmission selector lever towards the steering

wheel. Allow the selector lever to be positioned in

drive (D) by the transmission detent.

NOTE: Do not use the indicator pointer as a

reference to position the selected lever. When

performing linkage adjustment, pointer is ad-

justed last.

3.
Release the selector lever. The lever should be in-

hibited from engaging low range unless the lever is

lifted.

4.
Lift the selector lever towards the steering wheel,

and allow the lever to be positioned in neutral (N) by

the transmission detent.

5.
Release the selector lever. The lever should now

be inhibited from engaging reverse range unless the

lever is lifted.

6. A properly adjusted linkage will prevent the selector

lever from moving beyond both the neutral detent, and

the drive detent unless the lever is lifted to pass

over the mechanical stop in the steering column.

7.
In the event that an adjustment is required, place

the selector lever in drive (D) position as determined

by the transmission detent. See Steps 2 and 3.

8. Loosen the adjustment swivel at the cross-shaft,

and rotate the transmission lever so that it contacts

the drive stop in the steering column.

9. Tighten the swivel and recheck the adjustment. See

2 and 6.

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-25

Fig.
2PG - Chevrolet Shift Linkage Adjustments

10.

11.
Readjust indicator needle if necessary to agree with

the transmission detent positions. See Section 9.

Readjust neutral safety switch if necessary to pro-

vide the correct relationship to the transmission

detent positions. See Section 12.

CAUTION: Any inaccuracies in the above ad-

justment may result in premature failure of the

transmission due to operation without controls

in full detent. Such operation results in reduced

oil pressure and in turn partial engagement of

the affected clutches. Partial
of the

clutches with sufficient pressure to cause ap-

parent normal operation of the vehicle will

result in failure of the clutches or other in-

ternal parts after only a few miles of operation.

Floor Shift Linkage

Chevrolet Linkage Adjustment (Fig. 6PG)

1.
Loosely assemble Nuts (A) and (B) on Lower Rod (C).

2.
Set Transmission Lever (D) in drive position.
NOTE:
Obtain drive position by moving Trans-

mission Lever counter-clockwise to low detent,

then clockwise one detent position to drive.

3.
Set Control Pawl Lever Rod (E) in Neutral or drive

notch of Detent (F). See View A.

4.
Apply load in direction of Arrow (Y) on Actuating

Lever (G) until pawl Rod comes in contact with

Detent at Contact Point (Z). See View A.

5. Place a 7/64" Spacer (H) between Nut (A) and Swivel

(J),
run Nut (A) until it touches spacer. Remove

Spacer and apply load in the direction on Arrow (X)

until it touches Nut (A). Tighten Nut (B) against

Swivel and lock Swivel between Nuts (A) and (B).

See View B.

Chevelle Linkage Adjustment (Fig. 7PG)

1.
Assemble Nuts (A) and (B) on Lower Rod (C) loosely.

2.
Set Transmission Lever (D) in drive position.

NOTE:
Obrain drive position by moving Trans-

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-33

from rolling. The pointer on the indicator quadrant

should line up properly with the range indicators in all

ranges.

OIL LEAKS

Before attempting to correct an oil leak, the actual

source of the leak must be determined. In many cases

the source of the leak can be deceiving due to "wind flow1 f

around the engine and transmission.

The suspected area should be wiped clean of all oil

before inspecting for the source of the leak. Red dye is

used in the transmission oil at the assembly plant and

will indicate if the oil leak is from the transmission.

The use of a "black light"* to identify the oil at the

source of leak is also helpful. Comparing the oil from

the leak to that on the engine or transmission dip stick

(when viewed by black light) will determine the source

of the leak.

Oil leaks around the engine and transmission are gen-

erally carried toward the rear of the car by the air

stream. For example, a transmission "oil filter tube

to case leak" will sometimes appear as a leak at the

rear of the transmission. In determining the source of

an oil leak it is most helpful to keep the engine running.

The mating surfaces of servo cover, converter housing,

transmission case and transmission case extension

should be carefully examined for signs of leakage. The

vacuum modulator must also be checked to insure that

the diaphragm has not ruptured as this would allow trans-

mission oil to be drawn into the intake manifold. Us-

ually, the exhaust will be excessively smoky if the

diaphragm ruptures due to the transmission oil added to

the combustion. The transmission case extension rear

oil seal should also be checked. All test plugs should be

checked to make sure that they are tight and that there

is no sign of leakage at these points. The converter

underpan should also be removed. Any appreciable quan-

tity of oil in this area would indicate leakage at the pump

square seal ring, pump seal assembly, or pump bolt

sealing washers.

BASIC PRESSURE CHECKS

Four basic pressure checks are used for diagnosis and

operational checks for the Aluminum Powerglide trans-

mission. All checks should be made only after thoroughly

warming up the transmission.

• Wide Open Throttle Upshift Pressure.

• Idle Pressure in "Drive" Range.

• Manual "Low" Range Pressure.

• "Drive" Range Overrun (Coast) Pressure.

It is not recommended that stall tests be conducted

which would result in engine vacuum falling below 10" Hg.

Pressure gauge hose connections should be made at

the low servo apply (main line) test point (fig. 14PG).

Run the gauge line into the driving compartment by

pushing aside the mast jacket seal. The line out of the

way of the drivers feet and connect to pressure gauge

J-21867.

• Wide Open Throttle Upshift Pressure Check

Refer to the pressure check chart for upshift pressure
SERVO APPLY

PRESSURE

Fig.
14PG - Pressure Test Plug

points as indicated on the lower servo apply (main line)

gauge.

• Idle Pressure in "Drive" Range

In addition tp the oil pressure gauges, a vacuum gauge

is needed for this check.

With the parking brake applied and the shift selector

lever in "Drive", low servo apply (main line) pressure

should be as shown on the pressure check chart.

If pressures are not within these ranges, the following

items should be checked for oil circuit leakage:

1.
Pressure regulator valve stuck.

2.
Vacuum modulator valve stuck.

3.
Hydraulic modulator valve stuck.

4.
Leak at low servo piston ring (between ring and

bore).

5.
Leak at low servo piston rod (between rod and bore).

6. Leak at valve body to case gasket.

7.
Leak at valve body gaskets.

8. Front pump clearances.

9. Check passages in transmission case for porosity.

• Manual "Low" Range Pressure Check

Connect a tachometer, apply the parking brake, place

the selector lever in "Low" range, and adjust the engine

speed to 1000 rpm with the car stationary.

Low servo apply (main line) pressure should be as

shown on the pressure check chart.

Pressures not within this range can indicate the fol-

lowing possibilities:

1.
Partially plugged oil suction screen.

2.
Broken or damaged ring low servo.

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-36

TURBO HYDRA-MATIC TRANSMISSION

INDEX

Page

General Description . . , . 7-36

Maintenance and Adjustments . 7-37

Transmission Fluid 7-37

Fluid Level Indicator 7-37

Shift Control Linkage Adjustment ........... 7-37

Neutral Safety Switch Adjustment 7-37

Draining and Refilling Transmission . . . 7-37

Pressure Regulator Valve 7-38

Control Valve Body . 7-39

Governor ..'.... 7-40

Modulator and Modulator Valve 7-40

Parking Linkage . . 7-40
Page

Rear Seal -. 7-40

Other Service Operations . . 7-40

Transmission Replacement 7-40

Turbo Hydra-Matic Diagnosis Procedure. ......... 7-41

Sequence . ; ; 7-41

Oil Level and Condition Check 7-41

Manual Linkage 7-41

Oil Leaks .' 7-41

Case Porosity - Repair ................ 7-42

Oil Pressure Check 7-42

Transmission Shift Points 7-42

Special Tools 7-43

GENERAL DESCRIPTION

The Turbo Hydra-Matic transmission is a fully auto-

matic unit consisting primarily of a 3-element hydraulic

torque converter and a compound planetary gear set.

Three multiple-disc clutches, one sprag unit, one roller

clutch and two bands provide the friction elements re-

quired to obtain the desired function of the compound

planetary gear set.

The torque converter couples the engine to the plane-

tary gears through oil and provides hydraulic torque

multiplication when required. The compound planetary

gear set produces three forward speeds and reverse.

The
3-
element torque converter consists of a pump or

driving member, a turbine or driven member, and a

stator assembly. The stator is mounted on a one-way

roller clutch which will allow the stator to turn clock-

wise but not counter-clockwise.

The torque converter housing is filled with oil and

is attached to the engine crankshaft by a flex plate and

always rotates at engine speed. The converter pump is

an integral part of the converter housing, therefore the

pump blades, rotating at engine speed, set the oil within

the converter into motion and direct it to the turbine,

causing the turbine to rotate.

As the oil passes through the turbine it is traveling in

such a direction that if it were not re-directed by the

stator it would hit the rear of the converter pump blades

and impede its pumping action. So at low turbine speeds,

the oil is re-directed by the stator to the converter pump

in such a manner that it actually assists the converter

pump to deliver power or multiply engine torque.

As turbine speed increases, the direction of the oil

leaving the turbine changes and flows against the rear

side of the stator vanes in a clockwise direction. Since

the stator is now impeding the smooth flow of oil, its

roller clutch releases and it revolves freely on its shaft.

Once the stator becomes inactive, there is no further

multiplication of engine torque within the converter. At

this point, the converter is merely acting as a fluid

coupling as both the converter pump and turbine are

being driven at approximately the same speed - or at a

one-to-one ratio.

A hydraulic system pressurized by a gear type pump

provides the working pressure required to operate the

friction elements and automatic controls.

External control connections to transmission are:
Manual Linkage

Engine Vacuum

12 Volt Electrical

Signal
To select the desired op-

erating range.

To operate a vacuum mod-

ulator unit.

To operate an electrical

detent solenoid.

A vacuum modulator is used to automatically sense

any change in the torque input to the transmission. The

vacuum, modulator transmits this signal to the pressure

regulator for line pressure control, to the 1-2 accumula-

tor valve, and to the shift valves so that all torque re-

quirements of the transmission are met and smooth

shifts are obtained at all throttle openings.

The detent solenoid is activated by an alectric switch

on the carburetor. When the throttle is fully opened, the

switch on the carburetor is closed, activating the detent

solenoid and. causing the transmission to downshift at

speeds below approximately 70 MPH.

The selector quadrant has six selector positions: P,R,

N,D,
L2,L1.

P.
*
- Park position positively locks the output shaft to

the transmission case by means of a locking pawl

to prevent the vehicle from rolling in either di-

rection. The engine may be started in Park

position.

R. - Reverse enables the vehicle to be operated in a

reverse direction.

N.
- Neutral position enables the engine to be started

and run without driving the vehicle.

D,
- Drive Range is used for all normal driving condi-

tions and maximum economy. Drive Range has

three gear ratios, from the starting ratio to

direct drive. Detent downshifts are available by

depressing the accelerator to the floor.

L2.
- L2 Range has the same starting ratio as Drive

Range, but prevents the transmission from shift-

ing above second speed to retain second speed

acceleration when extra performance is desired.

L2 Range can also be used for engine braking.

L2 Range can be selected at any vehicle speed,

and the transmission will shift to second gear and

remain in second until the vehicle speed or the

throttle are changed to obtain first gear operation

in the same manner as in D Range.

CHIVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-37

LI.
- LI Range can be selected at any vehicle speed,

and the transmission will shift to second gear

and remain in second until vehicle speed is re-

duced to approximately 40 MPH, .depending on

axle ratio. LI Range position prevents the trans-

mission from shifting out of first gear.
It is very important that any communication concerning

the Turbo Hydra-Matic always contain the transmission

serial number and that all transmission parts returned

to Chevrolet Motor Division always be tagged with the

transmission serial number.

MAINTENANCE AND ADJUSTMENTS

TRANSMISSION FLUID

Transmission fluid level should be checked with trans-

mission warm and selector lever in "P" Park position,

every time engine oil level is checked or as specified in

Section 0 when engine oil is changed.

CAUTION: Since the Turbo Hydra-Matic trans-

mission is very sensitive to oil level, special

precautions should be taken when checking the

oil level, to insure against an overfifE

Transmission fluid should be changed as specified in

Section 0.

FLUID LEVEL INDICATOR

The fluid level indicator is located in the filler pipe at

the right rear corner of the engine. To bring the fluid

level from the add mark to the full mark add 1 pint.

Fluid level should be to the full mark with transmission

at normal operating temperature. With cold fluid the

level should be at the add mark or slightly below.

SHIFT CONTROL LINKAGE ADJUSTMENT

Adjust linkage as shown below and in Figure 2.

1.
The shift tube and lever assembly must be free in the

mast jacket See Section 9 for alignment of steering

column assembly if necessary.

2.
To check for proper shift linkage adjustment, lift the

transmission selector lever towards the steering

wheel. Allow the selector lever to be positioned in

drive (D) by the transmission detent.

NOTE: Do not use the indicator pointer as a

reference to position the selector lever. When

performing linkage adjustment, pointer is ad-

justed last.

3.
Release the selector lever. The lever should be in-

hibited from engaging low range unless the lever is

lifted.

4.
Lift the selector lever towards the steering wheel,

and allow the lever to be positioned in neutral (N) by

the transmission detent.

5.
Release the selector lever. The lever should now be

inhibited from engaging reverse range unless the

lever is lifted.

6. A properly adjusted linkage will prevent the selector

lever from moving beyond both the neutral detent,

and the drive detent unless the lever is lifted to pass

over the mechanical stop in the steering column.

See schematic diagram.

7.
In the event that an adjustment is required, place the

selector lever in drive (D) position as determined by

the transmission detent. See Steps 2 and 3.

8. Loosen the adjustment swivel at the cross-shaft, and
rotate the transmission lever so that it contacts the

drive stop in the steering column.

9. Tighten the swivel and recheck the adjustment. See

Steps 2 and 6. -

l(h Readjust indicator needle if necessary to agree with

the transmission detent" positions. See Section 9.

11.
Readjust neutral safety switch if necessary to pro-

vide the correct relationship to the transmission de-

tent positions. See Section 12.

12.
When properly adjusted the following conditions must

be met by manual operation of the steering column

shift lever:

a. From reverse to drive position travel, the trans-

mission detent feel must be noted and related to

indicated position on dial.

b.
When in drive and reverse positions, pull lever

rearward (towards steering wheel) and then re-

lease. It must drop back into position with no

restrictions.

NEUTRAL SAFETY SWITCH ADJUSTMENT

The neutral safety switch must be adjusted so that the

car will start in the park or neutral position, but will not

start in the other positions. For replacement refer to

Section 12 of this Manual.

DRAINING AND REFILLING TRANSMISSION

Drain oil immediately after operation before it has had

an opportunity to cool.

To drain oil proceed as follows:

1.
Remove bottom pan attaching screws, pan, and gas-

ket.

2.
Remove oil strainer. Remove "O" ring seal from

pick-up pipe and discard.

3.
Discard strainer if dirty.

4.
Install new "O" ring seal on pick-up pipe and install

strainer and pipe assembly.

5.
Thoroughly clean bottom pan.

6.. Affix new gasket to bottom pan with petroleum jelly.

7.
Install bottom pan with attaching screws and torque

to specifications;

8. If only the pan has been removed, pour approximately

7-1/2 pints of fluid into the transmission. If the

valve body has also been removed use 9-1/2 pints.

After a complete overhaul approximately 19 pints

are required. Be sure container, spout, or funnel is

clean.

9. Start engine and let idle (carburetor off fast idle

step).
Place selector lever in P position and apply

hand brake.

10.
With transmission warm (approximately 150°F), add

fluid to bring level to full mark on indicator.

CAUTION: Do not overfill. Foaming will re-

sult.

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-41

CAUTION: Use converter holding ToolJ-5384

when lowering transmission or keep rear of

transmission lower than front so as not to lose
converter.

The installation of the transmission is the reverse of

the removal.

TURBO HYDRA-MATIC DIAGNOSIS PROCEDURE

Accurate diagnosis of transmission problems begins

with a thorough understanding of normal transmission

operation. In particular, knowing which units are in-

volved in the various speeds or shifts so that the specific

units or circuits involved in the problem can be isolated

and investigated further. Analytical diagnosis will pro-

tect the technician from come backs and certainly will

improve owner satisfaction.

An important and often overlooked aspect of diagnosis

is finding out specifically what the customer is com-

plaining of. For this purpose a short ride with the cus-

tomer will often prove beneficial. It may be found that

the condition the customer wants corrected is standard

and should not be altered.

The following sequence, based on field experience, pro-

vides the desired information quickly and in most cases

actually corrects the malfunction without requiring the

removal of the transmission. Details of the items listed

in this sequence are covered further in the text.

SEQUENCE FOR TURBO HYDRA-MATIC

DIAGNOSIS PROCEDURE

1.
Check oil level and condition.

2.
Check and correct detent switch.

3.
Check and correct vacuum line and fittings.

4.
Check and correct manual linkage.

OIL LEVEL AND CONDITION CHECK

Always check the oil level before road testing. Oil

must be visible on dip stick prior to operating the ve-

hicle. Erratic shifting, pump noise, or other malfunc-

tions can in some cases be traced to improper oil level.

Oil level should be checked with the selector lever in

the Park (P) position, engine running, and the vehicle on

level pavement.

Fluid level should be to the FULL mark with the trans-

mission at normal operating temperature (170°-190°
F.).

With warm fluid (room temperature), the level should be

at or slightly below the ADD mark.

If oil level was low, refer to Oil Leaks.

The condition of the oil is often an indication of whether

the transmission should be removed from the vehicle, or

to make further tests. When checking oil level, a burned

smell and discoloration indicate burned clutches or bands

and the transmission will have to be removed.

MANUAL LINKAGE

Manual linkage adjustment and the associated neutral

safety switch are important from a safety standpoint

The neutral safety switch should be adjusted so that the

engine will start in the Park and Neutral positions only.

With the selector lever in the Park position, the park-

ing pawl should freely engage and prevent the vehicle

from rolling. The pointer on the indicator quadrant

should line up properly with the range indicators in all

ranges.
OIL LEAKS

Before attempting to correct an oil leak, the actual

source of the leak must be determined. In many cases,

the source of the leak can be deceiving due to "wind flow"

around the engine and transmission.

The suspected area should be wiped clean of all oil be-

fore inspecting for the source of the leak. Red dye is

used in the transmission oil at the assembly plant and

will indicate if the oil leak is from the transmission.

. The use of a "black light"* to identify the oil at the

source of leak is also helpful. Comparing the oil from

the leak to that on the engine or transmission dip stick

(when viewed by black light) will determine the source

of the leak.

Oil leaks around the engine and transmission are gen-

erally carried toward the rear of the car by the air

stream. For example, a transmission "oil filler tube to

case leak" will sometimes appear as a leak at the rear of

the transmission. In determining the source of an oil

leak it is most helpful to keep the engine running.

POSSIBLE POINTS OF OIL LEAKS

• 1. TRANSMISSION OIL PAN LEAK

a. Attaching bolts not correctly torqued.

b.
Improperly installed or damaged pan gasket.

c. Oil pan gasket mounting face not flat.

2.
REAR EXTENSION LEAK

a. Attaching bolts not correctly torqued.

b.
Rear seal assembly — damaged or improperly

installed.

c. Gasket seal — (extension to case) damaged or

improperly installed.

d. Porous casting.

3.
CASE LEAK

a. Filler pipe "O" ring seal damaged or missing;

misposition of filler pipe bracket to engine —

"loading" one side of
"O"
ring.

b.
Modulator assembly "O" ring seal
—
damaged or

improperly installed.

c. Governor cover, gasket and bolts — damaged,

loose; case face leak.

d. Speedo gear
—
"O" ring damaged.

e. Manual shaft seal — damaged, improperly in-

stalled.

f. line pressure tap plug — stripped, shy sealer

compound.

g. Parking pawl shaft cup plug
—
damaged, improp-

erly installed.

h. Vent pipe (refer to Item 5).

i. Porous case.

4.
FRONT END LEAK

a. Front seal - damaged (check converter neck for

nicks,
etc., also for pump bushing moved for-

ward);
garter spring missing from pump to con-

verter seaL

b.
Pump attaching bolts and seals
—
damaged, miss-

ing, bolts loose.

CHEVROLET a
SERVICE