PROPER SERVICE FLUID FOR MANUAL TRANSAXLE/TRANSMISSION

TRANSMISSION APPLICATIONS: SUBJECT: ------------------------- ------- 1986 1/2 - 1988 HM-282 PROPER SERVICE FLUID FOR MANUAL (MG1 AND MG2) TRANSAXLE/TRANSMISSION 1988 HM-290 (MCO AND MG5)

TRANSMISSION MODELS: VEHICLE APPLICATIONS: ------------------- -------------------- HM-282 - ALL; HM-290 - ALL A, J, L, N, P AND W CARS; C AND K TRUCKS

(Revised to correct P/N's on page 2.)

BULLETIN COVERS:

Proper service fluid for the HM-282 and HM-290 is important to prevent gear clash and/or increased shift effort.

DATE OF PRODUCTION CHANGE: (Figures 1 and 2) -------------------------- 1988 model year for the HM-282 (except early introduction L-Cars with model codes RRB or 7XBX) are factory filled with synchromesh transmission fluid (STF). This new fluid aids in reducing cold shift effort in this application.

SERVICE ACTION:

Reference chart below for the proper service fluid.

GM SERVICE MODEL MODEL YEAR FLUID NAME PART NUMBER ----- ---------- ---------- ----------- HM-282 1986 1/2 (PREFERRED SEE NOTE 1) 12345349 (1 QT.).946 L 1987 SYNCHROMESH TRANSMISSION 1988 FLUID

(OPTIONAL SEE NOTE 2) 1052931 (1 QT.).946 L MANUAL TRANSMISSION FLUID

HM-290 1988 MANUAL TRANSMISSION 1052931 (1 QT.).946 L FLUID

NOTE: 1) It is permissible and preferred to use synchromesh transmission fluid (STF) in past model HM-282 transaxles. STF will aid in reducing cold shift effort.

2) Synchromesh transmission fluid (STF) can be mixed with manual transmission fluid, but as the portion of manual transmission fluid increases, so does the shift effort.

IMPORTANT: DO NOT REFILL THE HM-282 OR HM-290 WITH ENGINE OIL OR AUTOMATIC TRANSMISSION FLUID. THESE HAVE DIFFERENT FRICTION COEFFICIENTS AND DO NOT WORK WELL WITH THE SYNCHRONIZERS, CAUSING GEAR CLASH AND/OR INCREASED SHIFT EFFORT.

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.