Owners manual

Installation Instructions
1966-1979 F-150 4WD
1978-1979 Bronco 4WD
Part # RAB27 / RAB47
Part # Description Qty
LRB27-5 LEFT RAD BRK 2.75"-SINGLE 1
RRB27-6 RIGHT RAD BRKT 2.75"-SINGLE 1
716X112FTB 7/16 X 1 1/2 FINE THRD BOLT 12
716FTN 7/16-20 FINE N/I LOCK NUT 12
716SAEW 7/16 SAE WASHER 24
Part # Description Qty
LRB47-5 LEFT RAD BRKT 4.75"-SINGLE 1
RRB47-6 RIGHT RAD BRK 4.75"-SINGLE 1
716X112FTB 7/16 X 1 1/2 FINE THRD BOLT 12
716FTN 7/16-20 FINE N/I LOCK NUT 12
716SAEW 7/16 SAE WASHER 24
1978-1979 Models
Installation Instruction:
1. Park the vehicle on level ground. Set the emergency brake and block the front tires.
2. Place jack under the left radius arm between axle housing and factory radius arm bracket.
Remove the bolts on the factory radius arm bracket from the frame and the cross member. (Save
the stock bolts, it may be necessary on some models to reuse them). Lower the jack down and
remove the bracket from the arm. Repeat the same procedure on the opposite side. Pull radius
arms down far enough to install the new brackets. Bolt new bracket to frame and cross member
where the stock brackets were removed. Install the 7/16” bolts with one washer against the head
of the bolt and one washer against the nut. Reinstall stock brackets on the bottom of new brack-
ets. (See Diagram on reverse side)
3. After all bolts are installed, torque all 7/16” bolts to 55-60 Ft. Lbs.
4. Once installed, check all components for proper clearance. Retorque all hardware after the first
100 miles and periodically there after.
1966-1977 Models
1. Procedure of installation is the same as above except that the stock radius arm brackets are rivet-
ed to the frame. Checking behind frame and removing any hoses or wires that may be in the way,
remove the rivets. Be sure not to damage the stock bracket.
2. Some vehicles will require drilling out the rivet hole to accept the 7/16” x 1 1/2” bolts.
3. On 1977 models, the stock radius arm brackets do not bolt to the outside face of the frame rails.
Once the new brackets are bolted in place, we recommend drilling the two upper holes per side
through the frame (at existing holes in the new bracket) and bolting them tight. Check for obstruc-
tions before drilling.
NOTE: If radius arm bushings are worn, they should be replaced at this time. Contact your dealer for pricing.
Seat Belts Save Lives, Please Wear Your Seat Belt
I-RAB27/47 2-03
RAB27
RAB47