Bronco Full Size V8-302 5.0L (1986)
Catalytic Converter: Customer Interest
Exhaust System - Noise/Vibration
Article No. 86-6-35
NOISE - EXHAUST SYSTEM CONTACT WITH RIGHT HAND FRAME RAIL (5.0L EFI)
LIGHT TRUCK 1985-86 F SERIES, BRONCO
The front catalytic converter may contact the frame bottom flange causing exhaust groundout. If the front converter is contacting the frame, or if
clearance is less than 10 mm (.40 inch) do the following:
1.
Loosen exhaust inlet pipe flange nuts (right and left sides).
2.
Insert pry bar between frame flange and converter flange and pry the converter away from the frame for 10 mm (.40 inch) clearance.
3.
Keep pry bar in position to maintain 10 mm (.40 inch) clearance, and retighten exhaust manifold nuts to 30 ft.lbs. torque.
Figure 28
If the 10 mm (.40 inch) clearance cannot be attained with Steps 1 through 3, grind the frame bottom flange to the 69 mm (2.75 inch) dimension as shown
in Figure 28 and per the following procedure:
1.
Mark the frame flange at the converter contact point, and 75 mm (3 inches) fore and aft of this point.
2.
Mark the 69 mm (2.75 inch) dimension on the frame flange at the converter contact point.
3.
Support the rear of the transmission, and remove the transmission support crossmember.
4.
Remove the Y pipe and catalytic converter assembly from the muffler inlet.
5.
Grind the frame flange to the 69 mm (2.75 inch) minimum dimension. The frame flange must not be notched. Blend the grind line 75 mm (3
inches) fore and aft from the contact point to a smooth curve. Remove burrs and sharp edges and apply chassis black paint.
6.
Reinstall the Y pipe and catalytic converter assembly. Position the converter with 10 mm (.40 inch) clearance to frame. Tighten exhaust manifold
nuts to 30 ft.lbs. torque.
