OIL PUMP ROTOR AND SLIDE SERVICE PROCEDURE 2004R/700R4
MODELS AFFECTED: 1981-1984 DEVILLE AND BROUGHAM
Service parts are available to service the oil pump rotor and slide (items #14 and #6, Figure 1) on all models of the THM 200-4R transmission used on 1981 through 1984 Deville and Brougham vehicles. The service procedure and parts information outlined in this bulletin must be followed to assure that proper end clearance of the oil pump rotor and/or slide is maintained during the overhaul of any THM 200-4R transmission oil pump assembly.
Service Procedure:
1. Disassembly and inspection of the oil pump.
A. Remove transmission from vehicle and disassemble the oil pump body assembly following procedures outlined in the appropriate model year Service Information Manual. Refer to Figure 1 for reference of the THM 200-4R transmission oil pump body assembly.
NOTICE: DO NOT attempt to service the oil pump rotor and/or slide if either the pump body or pump cover (items #3 or #17, Figure 1) surfaces are scored. Servicing the oil pump rotor and slide should be performed if ONLY the rotor and/or slide part(s) show wear.
2. Selecting the pump rotor and slide.
A. Use a vernier micrometer to measure the thickness of the original pump rotor and slide (Figure 2). To obtain the most accurate reading, measure on flat undamaged surfaces.
B. Using the original parts measurements, order service replacement parts from the following selective charts.
Chart Number 1 - Selective Pump Rotor
Part Number Thickness in MM. Thickness in Inches ----------- ---------------- ------------------- 8634091 17.948 - 17.961 0.7066 - 0.7071 8634092 17.961 -17.974 0.7071 - 0.7076 8634093 17.974 -17.987 0.7076 - 0.7081 8634094 17.987 -18.000 0.7081 - 0.7086 8634095 18.000 -18.013 0.7086 - 0.7091
Chart Number 2 - Selective Pump Slide
Part Number Thickness in MM. Thickness in Inches ----------- ---------------- ------------------- 8634081 17.948 - 17.961 0.7066 - 0.7071 8634082 17.961 - 17.974 0.7071 - 0.7076 8634083 17.974 - 17.987 0.7076 - 0.7081 8634084 17.987 - 18.000 0.7081 - 0.7086 8634085 18.000 -18.013 0.7086 - 0.7091
NOTE: The replacement part will provide the same clearance as the original oil pump assembly. The proper end clearance specification is 0.020 to 0.050mm. (.0008" to .002"). This dimension cannot be measured with a straight edge and feeler gage.
C. Hone both sides of the replacement rotor and slide with a fine oil stone to remove any burrs, and measure the parts with a vernier micrometer to assure proper thickness.
NOTE: Incorrect rotor thickness could result in a damaged oil pump assembly, and/or low oil pressure. Incorrect slide thickness could result in incorrect transmission line pressure.
3. Other Oil Pump Overhaul Parts:
A. Pump slide seal package (PIN 8634906) includes items #4, #5, #10 and #11 of Figure 1. Pump vane kit (P/N 8634904) includes items #12 and #15 of Figure 1.
4. Assembly:
A. Reassemble the oil pump assembly following procedures outlined in the Service Information Manual.
B. After assembling the oil pump into the transmission, install the torque converter and check for proper rotor and slide clearance by rotating the converter by hand. The converter should turn freely. If the converter does not turn freely, remove the converter, disassemble the oil pump and recheck the thickness of the pump rotor and slide.
C. If the converter does turn freely in Step B above, install the transmission into the vehicle.
D. Before road testing the vehicle, install gage into the line pressure tap of the transmission (driver's side of vehicle) and check oil pressure. Refer to the appropriate model year Service Information Manual for oil pressure specifications.
For warranty purposes, use labor Operation No. K7120 at 3.2 hours.
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.
