Vehicle - Moaning/Droaning at 55 to 65 MPH
85ford04
Article No. 85-4-39
MOAN/DRONE (5.0L/5.8L) - 2100
- 2800 RPM
LIGHT TRUCK 1983-85 ECONOLINE, F150-350, BRONCO
A moan/drone condition encountered at 55-65 mph may be a 2100-2800 engine rpm-related condition. Diagnosis and servicing will require a good road test followed by servicing of: 1) engine mounting, 2) exhaust hanger, 3) alternator pulley, and 4) alternator/thermactor braces depending on vehicle model and engine combination.
1. Road Test & Service Engine Mountings
a. Road test vehicle. The vehicle should be equipped with a portable tachometer and driven at a road speed of 55-65 MPH (engine speed of 2100-2800 RPM). The A/C system should be in the "off" position and the vehicle should be
evaluated on a smooth surfaced road or highway. If the road test verifies a "drone/ moan" condition, then the following procedures should be followed:
Figure 25:
b. On Bronco and F150-350 vehicles, loosen the No. 3 crossmember/rear engine support gussets at the attachment to the crossmember. If the gussets pull away from the crossmember, add shims to the gap. Retighten mounting bolts (install larger bolts if required). Refer to attached Figure 25).
c. On model F150-350 (4x2)/E150-350 vehicles, inspect rear engine insulator (mount) for correct usage of Engineering Part E3TA-6D091-A/Service Part E0TZ-6068-B (white color code). Install correct part if required. Inspect mount for correct orientation of "capture strap" which could bind up the mount.
With the vehicle on a two-post hoist, neutralize the front and rear engine support insulators
(front and rear engine mounts) by loosening the front and rear engine mounts attaching bolts (attaching front mounts to support bracket and the rear mount to the No. 3 crossmember.
Lower the vehicle and place safety stands under the front and rear axles. Start the engine and shift the automatic transmission into "drive" and back into "neutral" several times while engine is idling. With manual transmission, load engine by shifting transmission into forward and reverse gears and, with the parking brake partially applied, slip the clutch to load the engine. Raise the vehicle and remove the axle stands. Retorque front and rear engine mount attaching bolts (refer to Section 21-21 of 1983-1984 Light Truck Shop Manual for torque specifications). Lower vehicle and remove from hoist.
d. Re-road test to establish concern resolution. If concern is not resolved, continue procedure.
2. Double Link Exhaust Hanger Installation - F - 4 x 2 Models Only
a. 1980-83 Vehicles
Remove the intermediate exhaust hanger bracket assembly located at rear of the catalytic con- verter. Discard the hanger bracket assembly and install a new double link exhaust hanger bracket assembly.
b. 1984-85 Vehicles
1. Remove the intermediate exhaust hanger bracket assembly located at the rear of the catalytic converter.
Figure 23:
Figure 24 - Hanger Clearance:
2. Rework a new double link hanger to fit: See Figure 23 and 24.
a. remove lower portion of bracket
b. drill new 8.7 - 9.2 mm bolt holes in bracket
c. drill two new 8.7 - 9.2 mm mounting bolt holes in frame web.
d. install bracket on frame using N605906-S2 bolt and (2) nuts N620481-S50.
c. Re-road test to establish concern resolution. If concern is not resolved, continue procedure.
3. Alternator Drive Ratio Resolution: 5.8L - All Model Vehicles
a. Remove 2.62" alternator pulley and replace with 2.75" pulley.
b. Road test. If condition is still present, replace alternator pulley with 3.0" pulley.
c. Road test. If concern is still present, continue with procedure.
Figure 26 - Reinforced Braces:
Figure 27 - Reinforced Braces:
4. Addition of Alternator and Thermactor Pump Braces
Inspect the engine to verify that an air pump brace and an alternator brace is installed on the front end accessory drive area (refer to Figure 26 for 5.0L engine and Figure 27 for 5.8L engine). If no braces are currently installed, install the braces per Figures 26 and 27.
PART NUMBER PART NAME CLASS
E0TZ-6068-B Mount - rear engine BM
E0TZ-5A246-B Hanger - exhaust C
double link
C5AZ-10344-L Pulley - 2.75" duel shiv AG
C5AZ-10344-K Pulley - 2.75" single shiv AG
D2AZ-10344-A Pulley - 3.0" dual shiv CG
D20Z-10344-A Pulley - 3.0" single shiv C
E4TZ-9F492-A Brace - thermactor pump CG
5.0L
E4TZ-10145-A Brace - alternator CG
5.0L large frame CG
E4TZ-10145-B Brace - alternator CG
5.0L small frame
E4TZ-9B450-B Brake - thermactor pump C
5.8L
E4TZ-10N345-D Brace - alternator - C
5.8L small frame
E4TZ-10N345-E Brace - alternator - C
5.8L large frame
390158-S36 Stud - 5.0L/5.8L S
57103-S36 Stud and washer - S
5.0L
388469-S Stud and washer - S
5.0L/5.8L
382802-S2 Flange nut - 5.0L BR
34977-S2 Nut - 5.0L S
34987-S100 Nut - 5.8L SG
N620481-S50 Nut - exhaust hanger S
N605906-S2 exhaust hanger BS
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION:
OPERATION SERVICE TIME
SP6068A85 Road test and service
engine mounts
E 1.3 Hrs.
F (4x2) 1.6 Hrs.
F (4x4) 1.7 Hrs.
SP6068B85 Replace exhaust hanger;
rework exhaust hanger to fit 84/85
80-83 0.6 Hr.
84-85 1.0 Hr.
SP6068C85 Replace alternator pulley
- 5.8L (may be performed twice) .8 Hr.
SP6068D85 Install braces on
alternator and thermactor
- 5.0L, 5.8L-2V E 0.7 Hr.
F 0.6 Hr.
DLR. CODING: Basic Part No. - Code to part involved in final step taken. Condition code as applicable.