M/T - Grinding Noise While Shifting
91mitsubishi07
NO. TSB-91-21-001
DATE May, 1991
MODEL 1991 3000GT VR-4
SUBJECT:
GETRAG TRANSAXLE GRINDING NOISE
PURPOSE
This technical service bulletin (TSB) describes the installation of a clutch repair kit (part number MB896166) which can correct a grinding noise in the Getrag manual transaxle used on the 1991 3000GT VR-4.
DESCRIPTION
While shifting from 1st, 2nd, 3rd, or 4th gear, some Getrag - equipped manual transaxle 3000GT VR-4 vehicles may emit a grinding noise. This noise can be caused by a clutch which does not fully disengage. To correct this condition, vehicles manufactured after 02/04/91 (VIN JA(B)3XE74C* MY018423 and up, with the exception of MY018440) have been modified in production to move the disengagement point of the clutch closer to the top of its stroke, higher in its travel range.
Figure 1. Identification of Vehicles Modified in Production.:
A quick way to identify vehicles which have been modified in production is to observe the pedal stopper located underneath the clutch pedal (on the vehicle's bulkhead). The production modified vehicles have two rubber stoppers, side-by-side. Vehicles which have only one rubber stopper may require the clutch repair kit. Refer to Figure 1.
When this condition occurs on vehicles built prior to the modification date, it can be corrected by installing a clutch repair kit. The clutch repair kit should be installed whenever the transaxle must be replaced or when the clutch grinding noise is present.
DIAGNOSIS
Perform the following diagnosis to verify the need for transaxle replacement or installation of the clutch repair kit.
1. When the vehicle arrives at the dealership, determine from the customer the conditions under which the transaxle noise is heard.
A. When the grinding noise is heard during each shift (1-2, 2-3, 3-4, and 4-5), perform a complete clutch adjustment as shown in the 1991 300OGT Service Manual, Volume 1, Section 21.
1. If the clutch adjustment helps to reduce the grinding noise, install the clutch repair kit as described on pages 3-5 of this TSB.
2. If the clutch adjustment does not reduce the grinding noise, replace the manual transaxle assembly and install the clutch repair kit.
B. If the grinding noise is heard only during 1-2 and 2-3 shifts, do not perform a clutch adjustment and do not replace the manual transaxle. Install the clutch repair kit as shown on pages 3-5 of this TSB.
The remainder of this TSB describes component part numbers of the clutch repair kit, installation procedures, and warranty information.
PARTS INFORMATION
Part number and contents of clutch repair kit are:
Part No. Part Name
MB896166 Clutch Repair Kit
Contents of Kit: Qty
Clutch Release (Slave) Cylinder 1
Clutch Pedal Stopper 1
Plain Washer, Size 8 2
Spring Washer, Size 8 1
Clutch Cover Assembly 1
The clutch repair kit is available through your local PDC.
INSTALLATION PROCEDURES
1. Remove the transaxle assembly according to directions in the 1991 3000GT Service Manual, Volume 1, Section 22.
2. Remove the clutch cover assembly and install the new clutch cover assembly supplied with the repair kit. Refer to directions in the 1991 300OGT Service Manual, Volume 1, Section 21.
3. Remove the clutch release cylinder and install the new clutch release cylinder supplied with the repair kit. Refer to directions in the 1991 3000GT Service Manual, Volume 1, Section 21.
Figure 2. Location of Clutch Pedal Securing Bolt.:
4. Remove and discard the clutch pedal securing bolt located on the bulkhead, behind the clutch pedal. The securing bolt is directly above the clutch pedal rubber stopper. Refer to Figure 2 for location.
Figure 3. Installation of the New Pedal Stopper.:
5. Place the spring washer and one plain washer onto the threaded end of the new clutch pedal stopper. (Figure 3).
6. Install the clutch pedal stopper into the hole of the discarded clutch pedal securing bolt and tighten it 8.8 to 14.9 N-m (6.5 to 10.1 ft.lbs.). (Figure 3).
7. Adjust clearance between the pre-existing rubber stopper and clutch pedal to 10 mm (0.4 in). Adjustment is made by adding or subtracting plain washers from underneath the new pedal stopper. After adjustment, the pedal should be touching the newly installed pedal stopper. (Figure 3).
Figure 4. Clutch Pedal Stroke and Free-Play Adjustment.:
8. Adjust the clutch pedal stroke and free-play according to directions in the 1991 3000GT Service Manual, Volume 1, Pages 21-5 (Step 2) and 21-6 (Step 4). Also refer to Figure 4 on page 5 of this TSB.
Utilize the newly established clearance shown below:
Pedal Stroke: 150 to 155 mm (5.9 to 6.1 inches)
Pedal Free Play: 12 to 20 mm (0.5 to 0.8 inches)
Figure 5. Adjustment of Clutch Interlock Switch.:
9. Adjust the clutch pedal interlock switch according to directions in the 1991 3000GT Service Manual, Volume 1, Page 21-5 (Step 3). The clearance specification is 10 to 14 mm (0.4 to 0.6 inches). Also refer to Figure 5.
10. Reinstall the transaxle assembly according to directions in the 1991 3000GT Service Manual, Volume 1, Section 22.
WARRANTY INFORMATION
Utilize standard warranty procedures and practices.