A/T - Oil Pan Leak
Number: 83-117Section: 7A (VIIc)
Date: Dec., 1983
Subject: OIL PAN LEAKS ON THM 200/200C TRANSMISSION
Model and Year: 1981 CHEVETTE, MALIBU WAGON, MONTE CARLO, EL CAMINO, IMPALA, CAPRICE, CAMARO AND LUV
1983 CAMARO, S-TRUCK, CHEVETTE, MALIBU, MONTE CARLO, IMPALA AND CAPRICE
FIGURE 1 - TRANSMISSION OIL PAN:
FIGURE 2 - HEX HEAD SCREW AND CONICAL WASHER ASSEMBLY:
TO: ALL CHEVROLET DEALERS
Beginning September 6, 1983, a new transmission oil pan (Figure 1) and hex head screw and conical washer assembly (Figure 2) went into production for all THM 200C transmissions.
Refer to the chart below and verify serial and model numbers. If the serial number is prior to the number on the chart then follow this procedure.
MODEL SERIAL
BH 48567
OI 17716
CZ 1041
JY 1074
OR 1071
OU 1724
SERVICE PROCEDURE
1. Diagnose source of leak to be certain leak is from the transmission oil pan area (refer to Chevrolet Bulletin 83-I-50 for diagnosing transmission oil leaks).
2. If a leak is determined to be from the transmission oil pan area:
- Remove the oil pan and gasket.
- Clean the case oil pan face (with solvent) and visually inspect the case oil pan face for nicks, and RTV sealant (room temperature Vulcanizing sealant). Make sure all RTV sealant is removed from the case oil pan face.
FIGURE 3 - TRANSMISSION OIL SCREEN:
3. If the THM 200 transmission being serviced is a 1979 or earlier model verify which transmission oil screen is being used (Figure 3). If the old oil screen is being used (Figure 3) it must be replaced with the new oil screen (Figure 3) provided in the service package.
4. Replace the former oil pan (Figure 1) hex head screws (Figure 2) with new oil pan (Figure 2) and hex head screw and conical washer assemblies. (Figure 2) order Service Package, P/N 8638929. This service package contains the following:
1 - P/N 8648160 - New Oil Pan
1 - P/N 8648161 - Transmission oil Pan Gasket
11 - P/N 8643683 - Hex Head Screws and Conical Washer Assembly
1 - P/N 8630789 - Screen Assembly Transmission Oil
1 - P/N 8628300 - Gasket, Screen to Valve Body
1 - P/N 8632952 - Instruction Sheet
These parts are also available separately.
Torque all hex head screws to 11.0 N-m (9.0 ft.lbs.) then retorque all the hex head screws a second time to the same specifications as above. The second retorque is important because the gasket material relaxes after the first tightening.