BURNED OVERRUN CLUTCH 700R4 PLATE ASSEMBLY PROD. CHANGE

VEHICLES AFFECTED: 1982-84 Vehicles Equipped With THM 700-R4 Transmission

Beginning April 16, 1984, (Julian Date 107) a new input housing and shaft assembly and oil pump assembly went into production for all models of the THM 700-R4 transmission. In addition, new torque converters went into production for all 298 mm applications (4.1L in/line L6; V-8 gas and diesel engines).

All transmissions built starting with Julian date 107 are stamped with the letter "T" on the pan rail after the transmission identification number (fig. 1). The letter "T" will only be used for the remainder of the 1984 model year.

These production changes eliminate the possibilty of burned clutch packs in the input housing which may be due to hairline cracks which could develop across the ring grooves in the turbine shaft. A crack in this area of the turbine shaft on models built prior to this change may cause one or any combination of the following clutches to slip and overheat due to loss of apply pressure:

A. Overrun clutch pack B. Forward clutch pack C. 3-4 clutch pack

Service Information:

1. If any 1982, 1983 or 1984 THM 700-R4 transmission (built prior to Julian Date 107) experiencing burned clutch packs within the input housing assembly, check for a possible cracked turbine shaft.

Important: A hairline crack in the turbine shaft is not always detected by visually inspecting the shaft. To determine if the shaft is cracked, inspect the stator shaft sleeve for possible score marks in the inner diameter(Fig. 2). If scoring is found, the probable cause is a crack in the turbine shaft which opens under torque conditions and produces the scoring and burned clutch packs. If this condition is found, replace both the input housing & shaft assembly and the oil pump assembly complete. Due to recent changes in the oil pump cover and pump body castings, these parts are serviced as an assembly for 1982 through 1984.

2. Oil pump assemblies, input housing and shaft assemblies, and converters can be purchased separately as shown in the following charts #1, #2, and #3, respectively. However, any transmission built prior to this change (1982, 1983, or 1984 not identified by a "T") must use the part numbers shown in the column marked "before Julian Date 107". Any 1984 transmission built after this change (identified by the letter "T") must use the part numbers in the column marked "after Jullan Date 107".

3. Due to the changes made on the above parts, those shown for use prior to the change must not be interchanged with those shown for use after the change. Interchanging these parts will result in conditions such as:

A. Interference fits B. Loose fits C. No drive D. Possible repeat cracks in the turbine shaft. E. Future confusion if the transmission should require additional service

CHART 1

YEAR MODELS PART NAME BEFORE STARTING ---- ------ --------- JULIAN DATE WITH JULIAN 107 DATE 107 1982 T5, YK, YL, T6, TW, YA. --- -------- TC, TE, TH, TJ, TK, M2, OIL PUMP M4, M5, M7, MB, MC, MD, ASSY. COMPLETE 8647967 ME, Y3, Y4, Y6

1982 M6, MH, TN, TP OIL PUMP 8647968 ASSY. COMPLETE

1983 TC, MB, MC, MJ, VN, TE, TH, TK, MD, ME, MW, VH, OIL PUMP T2, VA, YN, ML, MP, MS, ASSY. COMPLETE 8647967 T7, MK, YG, PQ, YP, YK Y9, YF

1983 YH, TS, TZ, T8, TP, MH, OIL PUMP 8647968 VJ, TL ASSY. COMPLETE

1984 MB, MC, MD, VH, TE, ME, OIL PUMP MK, MJ, VN, TC, TH, MW, ASSY.COMPLETE 8647967 TK, VA, YF, PQ, YG, YP, YK, Y6, YN, YA, Y9, YW

1984 TL, TZ, ML, MP, MS, T7, OIL PUMP YH, Y7, Y8, TS, MR, TG, ASSY. COMPLETE 8647968 8654309 TD,

1984 MH, VX, VJ, VE, TM, T8, OIL PUMP MG ASSY. COMPLETE 8647969 8654310

CHART 2

YEAR MODELS PART NAME BEFORE STARTING ---- ------ --------- JULIAN DATE WITH JULTAN 107 DATE 107 --- --------- 1982 T5, YK, YL, T6, TW, YA, TC, TE, TH, TJ, TK, M2, INPUT HOUSING *8647127 M4, M5, M7, MB, MC, MD, AND SHAFT ASSY. (8647963) ME, Y3, Y4, Y6, M6, MH, TN, TP

1983 TC, MB, MC, MJ, VN, TE, TH, TK, MD, ME, MW, VH, INPUT HOUSING *6647127 TZ, MK, YN, YF, YG, YP, AND SHAFT ASSY. (8647963) YK, Y9, TS, T8, TP, MH, VJ, TL

1983 T2, VA, ML, MP, MS, T7, INPUT HOUSING *8647128 YH, YF, PQ AND SHAFT ASSY. (8647965)

1984 MB, MC, MD, VH, MR, TG, ME, MK, MJ, VN, TC, TH, MW, TD, TK, MG, MH, VX, INPUT HOUSING *8647127 VJ, TL, VE, TM, TZ, T8 AND SHAFT ASSY. (8647963) 8654156 TE, YP, Y8, TS, YK, Y6, YN, YA, Y9, YW, YG

1984 VA, ML, MP, MS, T7, YH, INPUT HOUSING *8647128 YF, PQ, YR AND SHAFT ASSY. (8647965) 8654155

These part numbers will be superseded by the numbers shown in Approx. in October 1984.

Torque converter assemblies for 1982, 1983, and 1984 models built prior to Julian date 107, use current released part numbers.

Torque converter assemblies for 1984 models starting with Julian date 107, use the part numbers as shown in the chart below.

CHART 3

1984 MODEL TORQUE CONVERTER ASSEMBLY PART NUMBERS STARTING WITH JULIAN DATE 107 -----------------------------

MG, MH, VX, VJ, VE, TM, CONVERTER ASSY. 8647903 TZ, T8

YK, Y6, MD, VH, MR, TG, TE, ME, MK, TH, MK, TH, CONVERTER ASSY. 8647901 MW, TD, TK

Y8 CONVERTER ASSY. 8647900

YG, TS, YN, YA, Y9, YW, CONVERTER ASSY. 8647904

YP, MB, MC, MJ, VN, TC CONVERTER ASSY. 8647902

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.