M/T - Low Frequency Droning Noise

91mitsubishi01

NO. TSB-91-22-001

DATE January, 1991

MODEL 1990 Precis


SUBJECT:

MANUAL TRANSAXLE DRONING NOISE


TSB Revision TSB-91-22-001


PURPOSE

This bulletin describes a low frequency droning noise which may be heard from a 1990 Precis equipped with five-speed or four-speed manual transaxle.

DESCRIPTION


The drone is most noticeable in fifth gear, cruising at approximately 50-60 mph. Moving the shift lever slightly to the right will cause the noise to stop. To a lesser extent, the drone is sometimes heard while in first and second gear of both four-speed and five-speed manual transaxles.

This noise is caused by excessive run-out of the 3rd/4th synchronizer sleeve, which creates a vibration in the 3rd/4th shift fork.

AFFECTED VEHICLES

1990 Precis with KM-200 or KM-201 manual transaxle.

CORRECTIVE ACTION





To reduce the noise, replace the following component parts:

- 3rd/4th shift fork

- shift fork spring pin

- 3rd/4th synchronizer hub and sleeve

Details of the replacement procedure are shown in the 1990 Precis Service Manual, Section 43.

WARRANTY INFORMATION

Please utilize the standard warranty procedures that apply to this type of corrective action.


PARTS INFORMATION

Part Number Part Name

43861-34020 Shift fork (3rd & 4th)

43842-21000 Spring pin (for shift fork)

43360-34000 Hub & Sleeve-Syncro (3rd & 4th)


Replacement parts have been closely reinspected to ensure correct tolerances. Part numbers and appearances of replacement parts are unchanged from original parts.