L-Series Sedan (4 Door) 2WD F4-1781cc 1.8L SOHC (MPFI) (1985)
Muffler: All Technical Service Bulletins
Muffler - Vibration Noise While Driving
NUMBER 09-22-86
APPLICABILITY
ALL 1985 AND 1986 VEHICLES
DATE 05-21-86
SUBJECT:
MUFFLER NOISE
Should you encounter a muffler that gives off a vibration noise while driving, a simple procedure of drilling a hole in the outer skin can be performed to
alleviate the condition.
By drilling a hole in the outer skin of the muffler allows ambient air to travel freely between the muffler skin and the inner plate. The air cools the inner
plate to prevent it from warping from heat expansion and resonating on the outer skin.
FIGURE 1
First verify the noise. Then raise the vehicle and locate the lot number on the support plate at the front of the muffler. If the lot number is not within the
range shown in Figure 1, replace the muffler following the repair steps found in the 1986 Service Manual, section 2- 9, page 7. If the lot number is within
the range shown in Figure 1, perform the operational steps that follow:
MATERIALS REQUIRED
High Temperature Paint (Spray or Brush-on) All Purpose Grease
TOOLS REQUIRED
Drill 5/64" Drill Bit Drill Stop Hammer Center Punch Tape Measure
FIGURE 2
STEP 1) Locate a point as shown in Figure 2.