For 1990-2009 cars

# THM TRANS OIL LEAKS USE TRACING POWDER/FIND LEAK

If a transmission oil leak is detected, it is very important that the location and type of leak are diagnosed properly.

The following procedure will help in diagnosing the type and location of the leak on the transmissions listed above.

#### DIAGNOSIS PROCEDURE:

The following procedure can be performed on car.

1. Clean all residual oil from the transmission, concentrating on the transmission oil pan to case mating areas (all models), T.V. cable connector (all models), transmission oil pan to sprocket cover interface area (325-4L model), final drive to case connection (325-4L model), valve body cover to transmission oil pan interface area (125C model) (C. R.C.'s electramotive cleanser, or equivalent is recommended).

2. Dust the entire transmission with a white powder. (e.g., leak tracing powder or foot powder spray).

3. After normal operating temperature (170 DEG F) has been obtained, let the transmission stand for at least (30) thirty minutes.

4. Inspect the transmission for leakage by following red oil traces left in the powder. (If residual oil is left on the transmission oil pan or sprocket cover, it will necessitate the cleaning and dusting procedure to be repeated.)

5. Once the leak has been diagnosed as to location and type (wetness, moist, damp etc.) refer to the following repair procedure:

#### REPAIR PROCEDURE:

125C, 200C, 325-4L, 200-4R (Figures 1,2,3 & 4)

ITEM* PART NAME LEAK CAUSE CORRECTION ---- --------- ----------- ---------- 2 Transmission Oil Pan Low Bolt Torque Retorque & Recheck Bolts

Gasket Leak Remove & Replace Gasket

Broken R.T.V Bead Remove Cover & Reseal with R.T.V.

3 T.V. Cable Connector Cocked & Remove Connector & Connector "C" Interfering with Mount Reistall

Seal Damaged Remove & Replace Seal

Connector Cracked Remove & Replace Cable

Fill Tube "D" Seal Missing or Remove Fill Tube & Damaged Replace Seal

Electrical Connector "O" Ring Missing or Remove Connector & "E" Damaged Repplac Seal

Connector Missing or Remove & Replace Damaged Connector

4 Manual Shaft Seal Assembly Damaged Remove & Replace Seal

5 Governor Cover "O" Ring Damaged Remove & Replace "O" Ring

Low Bolt Torque Retorque Bolts & Recheck

6 Speedo Fitting Low Bolt Torque Retorque Bolt & Recheck

*"Item" refer to number on Figures 1 thru 4

125C, 200C, 325-4L, 200-4R (Figures 1,2,3,& 4 ) Cont.

ITEM* PART NAME LEAK CAUSE CORRECTION ---- --------- ----------- ---------- Seal Damaged Remove & Replace Seal

7 Servo cover "O" Ring Damaged Remove & Replace "O" Ring

8 Cooler Fittings Low Fitting Torque Retorque Fitting & Recheck

Cracked Fitting Replace & Retorque Fitting

11 converter Asm. Hub or Seam Weld Leak Remove & Replace Converter

12 Converter Seal Seal Damaged Remove & Replace Seal

13 Vent Leaking Check for the following & correct as necessary A) Oil Overfil B) Blocked Drainback Holes in Sprocet Support C) Engine Coolant in Oil

* "Item" refer to number on Figures 1 thru 4

325-4L ONLY (Figure No. 1)

1 Sprocket Cover R.T.V. Bead Broken Remove Cover & Reseal R.T.V. Cracked Cover Replace Cover Corner "A" Leak Past Design Case-Drill Thru & Add Nut, Bolt & Lock Washer Corner "B" Leak Remove Cover & Reseal R.T.V. 9 Case Face to Final Drive Low Bolt Torque Retorque Bolts & Recheck

10 Case Face to Final Plug Loose (Leaking) Remove Plug & Replace Drive Governor Cover (Loctite Plug)

Plug High Drive Plug into Case Below Face Surface

*"Item" refer to number on Figure No. 1

125C ONLY (Figure No. 4)

16 Valve Body Cover to Low Bolt Torque Retorque Bolts & Cass Assembly Recheck R.T.V. Bead Broken Remove Cover & Reseal with R.T.V. Gasket Leak Remove Gasket & Replace 17 Axle Shaft Seals Seals Damaged Remove Seal & Replace

*"Item" refer to number on Figure No. 4

200C & 200-4R ONLY (Figure 2 & 3)

14 Pump Assembly Pump Bolts Loose Retorque Bolts & Recheck Pump "O" Ring Cut Remove "O" Ring & or Damaged Replace Pump Porosity Replace Pump 15 Rear Extension Seal Torn or Damaged Remove Seal & Replace

*"Item" refer to number on Figures 2 & 3

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.