Mitsubishi 380. Manual - part 840

LOWER ARM

FRONT SUSPENSION

33-14

REMOVAL SERVICE POINT

.

<<A>> LOWER ARM AND KNUCKLE DISCON-
NECTION

CAUTION

• Do not remove the nut from ball joint. Loosen it and use 

special tool MB991897 to avoid possible damage to ball 
joint threads.

• Hang special tool MB991897 with a cord to prevent it 

from falling. 

1. Loosen nut and remove bolt. If bolt is difficult to remove use 

a soft drift to loosen from knuckle.

2. Use a large flat blade to spring clamp apart if required and 

remove ball joint from knuckle.

INSPECTION

M1332001700316

• Check the bushing for wear and deterioration.

• Check the lower arm assembly for bending or breakage.

• Check all bolts for condition and straightness.

.

LOWER ARM BALL JOINT BREAKAWAY TORQUE 
CHECK

Required Special Tool:

• MB990326: Preload Socket

1. Move the ball joint stud several times and install the lower 

arm nut on the stud. Using special tool MB990326, measure 
the ball joint breakaway torque.

Standard value: 3.5 

− 6.9 N⋅m (31 − 61 in-lb)

2. If the measured value is not within the standard value, or if 

the ball joint is difficult to turn or does not turn smoothly, 
replace the lower arm assembly.

.

LOWER ARM BALL JOINT DUST COVER CHECK

1. Check the dust cover for cracks or damage by pushing it 

with your finger.

2. If the dust cover is cracked or damaged, replace the lower 

arm assembly.

NOTE: Cracks or damage to the dust cover may cause 
damage to the ball joint. When it is damaged during service 
work, replace the dust cover.

12DB014A

BOLT

NUT

AC305846 AB

MB990326

LOWER ARM

FRONT SUSPENSION

33-15

LOWER ARM BALL JOINT DUST COVER 
REPLACEMENT

M1332008200282

Required Special Tool:

• MB990776: Front Axle Base

If the dust cover is damaged accidentally during service work, 
replace the dust cover as follows:
1. Remove the dust cover.

2. Apply the multipurpose grease SAE J310, NLGI No.2 or 

equivalent to the lip and the inside of a new dust cover.

Grease amount for the inside the dust cover (refer-
ence): 13 

± 0.5 g (0.45 ± 0.02 oz)

3. Using special tool MB990776, drive in the dust cover until it 

is fully seated.

4. Position the dust cover as shown in the illustration. Make 

sure that there is no abnormal bulge or pressure applied to 
the dust cover.

5. Check the dust cover for cracks or damage by pushing it 

with your finger.

AC305847

AB

MB990776

DUST COVER

AC205611

AC305736 AB

32.3 mm
1.27 in

DUST COVER

LOWER ARM

FRONT SUSPENSION

33-16

LOWER ARM BUSHING (REAR) REPLACEMENT

M1332008100371

Required Special Tools:

• MB991963: Suspension Bushing Arbor

• MB990889: Rear Suspension Bushing Ring

• MB990890: Rear Suspension Bushing Base

Replace the lower arm bushing as follows:

1. Use special tools MB991963 and MB990890 to drive out the 

lower arm bushing. 

AC306250 AB

LOWER ARM BUSHING

AC207421

AB

MB991963

MB990890

LOWER ARM
ASSEMBLY

LOWER ARM 
BUSHING

LOWER ARM

FRONT SUSPENSION

33-17

2. Position the lower arm bushing so that its projections are 

positioned as shown, and then use special tools MB991963, 
MB990889 and MB990890 to press in the lower arm 
bushing.

CAUTION

When pressing in the lower arm bushing, take care not to 
deform the lower arm. 
3. Press the lower arm bushing until its outer tube is flush with 

the lower arm assembly surface while checking that the 
press-in pressure is at the standard value. If the press-in 
pressure is lower than the standard value, replace the lower 
arm assembly.

Standard value: 10 kN (2,248 pounds) or more

AC207423

AB

PROJECTIONS

30˚± 3˚

LOWER ARM ASSEMBLY

AC207422

AB

MB991963

MB990890

LOWER ARM
ASSEMBLY

MB990889

LOWER ARM 
BUSHING
OUTER TUBE