A/T - Oil Leak Diagnosis
Number 83-T-79 Section 7 Date 8/84DIAGNOSING TRANSMISSION OIL LEAKS
Subject: THM 700-R4
To diagnose a transmission oil leak properly the following procedure. should be used.
DIAGNOSIS PROCEDURE
The following procedure is performed on car:
1. Clean all residual oil from the transmission (C.R.C.'s electramotive cleanser, or equivalent is recommended). Repeat cleaning process until all residual oil is removed.
2. Dust the entire transmission with a white powder (eg., leak tracing powder or spray foot powder). If residual oil is left on the transmission, it will necessitate the cleaning and dusting procedure be repeated.
3. After normal operating temperature (170~F) has been obtained, let the transmission stand for at least thirty (30) minutes (engine off).
4. Inspect the transmission for leakage by following red oil traces left in the powder.
5. Once the leak has been diagnosed as to location and type (wetness, moist, damp, etc.), refer to the following repair procedure:
IMPORTANT: Steps 1-4 should be used when diagnosing any transmission for an oil leak.
6. Repeat Steps 1-4 following repair of suspect leak source.
Figure 1 - POSSIBLE LEAK POINTS - THM 700R4:
Figure 2 - Servo Cover Assembly:
Figure 3 - Drainback Passage:
REPAIR PROCEDURE:
POSSIBLE LEAK POINT
FIG-
URE ITEM
NO. NO. PART NAME LEAK CAUSE CORRECTION
1 1 Transmission Oil Pan Low Bolt Torque Retorque & Recheck Bolts
Gasket Leak Replace Gasket
Porosity Repair Per Service Manual
1 2 Case Cracked Replace Case
1 3 Cooler Fittings Low Torque Reseal & Retorque
or Pressure Plugs
1 4 T.V. Cable Connector Cocked & Remove Connector & Reinstall
Connector Interfering With
Mount
Seal Damaged Replace Seal
Connector Cracked Replace Connector
Cable
1 5 Servo Cover Porosity Replace (See Figure 2)
2 1 & 2 "O" Ring Damage Replace (See Figure 2)
1 6 Fill Tube Seal Missing or Remove Fill Tube & Replace Seal
Damaged
Tube Bent Above Replace Tube
Transmission
1 7 Converter Seal Seal Damaged Replace Seal
3 - Seal Blown Out (see Figure 3) Check For
Oversized Seal Bore or Restricted Drainback Passage.
1 8 Pump Assembly Pump Bolts Loose Retorque & Recheck
Pump To Case Ring Replace Ring & Recheck.
Cut or Damaged If Leak Persists, Replace
Oil Pump Body With Part Number 8642986 or Repair (See Figure 3).
3 - Pump Porosity Replace Oil Pump Body Part
Number 8642986
1 9 Converter Assembly Hub or Seam Weld Replace Converter.
1 10 Vent Leaking Check for Oil Overfill &
Correct As Necessary
REPAIR PROCEDURE:
POSSIBLE LEAK POINT
FIG-
URE ITEM
NO. NO. PART NAME LEAK CAUSE CORRECTION
1 11 Electrical Connector "O" Ring Missing Remove Connector & Replace
Or Damaged "O" Ring
Connector Damaged Replace Connector
1 12 Manual Shaft Seal Assembly Replace Seal
Damaged
1 13 Governor Cover Gaps in Sealant Reseal with Loctite
1 14 Speedo Fitting Low Bolt Torque Retorque & Recheck
Seal Damaged Replace Seal
1 15 Rear Extension Porosity Repair Per Service Manual
Cracked Replace
Low Bolt Torque Retorque & Recheck
Extension to Case Replace Seal
Seal Damaged
Extension Seal Replace Seal
Assembly Torn Or Damaged