DIY Network

1938 Packard: Steering Pitman-Arm Adjustment From "Classic Car Restoration" episode DCR-406

The steering system is one of the most important restorations on the vehicle since it represents the driver's contact and communication with the road.

In this episode of Classic Car Restoration, host Mark Lambert focuses on the steering system in the restoration of a 1938 Packard Club Coupe. So far in the restoration, the cooling system, fuel, brake and ignition systems have all been addressed. In this first segment of episode 406, Mark begins work on adjustment of the pitman arm and steering-wheel alignment.

Following below is a summary of the major steps in the procedure as shown in the episode.

Materials used in this episode:

Standard automotive tools (socket-wrenches, screwdrivers, nut-drivers, etc.)
Jack and jack-stands
Grease gun
Heavy gear-lube
Tap-hammer
Bench vise
Replacement steering center pivot-pin
Replacement bearings
Replacement cotter pins
Anti-seize compound
Eye protection
Protective gloves

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Note: This is a summary of steps included in the automotive restoration procedures shown in this episode of Classic Car Restoration. These are general guidelines for restoration procedures on this particular make and model of vehicle, and for the level of restoration selected for this project. There may be variations in procedures depending model, condition of vehicle, level of restoration undertaken and the types of replacement parts or upgrade kits selected. Always follow proper safety precautions, and read and follow manufacturer's guidelines, diagrams and safety notices that come with any replacement parts or kit that you select.

Safety Alert: Always wear eye protection when working with power tools or pneumatic tools.

Figure A

Steps:

The steering system is one of the most important restorations on the vehicle since it represents the driver's contact and communication with the road. In the initial test drive, the '38 Packard exhibited considerable play in the steering -- so much so that it made the car difficult to drive. The first step in servicing the steering system on this car is to check and adjust the steering-gearbox play.

• First, with the ignition turned off, simply turn the steering wheel (figure A) and observe the amount of movement that occurs before you see a response from the front tire. In our case, we could move the wheel about three inches in each direction. Ideally, there should be no more than about 1/4-inch of play.

• Important: This type of work on the steering system should only be undertaken with the car supported either on a lift or (as in our case) by a jack and jack-stands.
  

• To properly adjust the steering gearbox, the pitman arm must be disconnected from the rest of the steering linkage (figure B).

• Using needle-nosed pliers, carefully remove the cotter pin from the pitman arm (figure C).

  Figure B

  Figure C

  
  

• Using a flathead screwdriver, unscrew and remove the threaded cap from the pitman arm (figure D) to reveal the ball-and-socket joint.

• Pry the linkage loose using a pry bar and check the amount of play in the pitman arm. (Ours was significant which was indicative that the steering adjustment was off-center.)

• Use a 5/8" wrench to remove the cap from the steering gearbox so that you can look down into the gearbox and check the amount of lubrication (figure E). Since ours was lacking sufficient lubrication, we filled the steering box with heavy gear lube.

• Replace the cap.

  Figure D

  Figure E

  
  

  	Figure F
  	Figure G

• The objective for adjusting the steering box is to center the steering wheel while adjusting the steering lever and shaft. Mark the steering wheel on one spoke, then turn the steering wheel all the way from lock to lock, counting the complete rotations as you go. You can then divide that number by one half to arrive at the exact center position for the steering wheel. In our case, the rotations totaled 4-2/3 turns, so we then rotated back in the opposite direction 2-1/3 turns (half the total) to arrive at the center position (figure F). In our case, this setting resulted in the steering wheel being in the proper orientation with the emblem on the horn button being at the proper upright position.

• With the steering wheel at the center position, adjust the pitman arm using a 3/4-inch wrench and large slotted screwdriver (figure G). Unlock the lock-nut on top of the gearbox. While holding the main screw stationery with the screwdriver, rock the pitman arm back and forth to check for play. Then begin tightening down the main screw to tighten down the gearing and remove the unnecessary slack.

• If the adjustment is done properly and secured, the pitman arm can be moved in a smooth motion and will result in the steering wheel turning -- also with smooth action under gentle pressure.
  

RESOURCES :


Resources and Special Thanks for Classic Car Restoration 400 series


The Packard Club
Columbus, Ohio
(National & regional clubs, car shows & judging, magazine, resources, etc.)
The Cormorant magazine
The Packard Club
www.packardclub.org

Packards International Motor Car Club
(National owner's club, judging rules, magazine, newsletter and other resources)
Santa Ana, CA
Packardsinternational.com

Packards of Chicagoland
(Regional affiliate of The Packard Club)
Elmhurst, IL
Packards of Chicagoland

America's Packard Museum
Dayton, Ohio
www.americaspackardmuseum.org

The National Packard Museum
Warren, OH (the birthplace of the Packard)
www.warren.org

The Packard Motor Car Foundation
(Foundation for preserving the Packard marque) Restoring the Packard Proving Grounds and other Packard activities.
www.packardmotorfdn.org

Motorbooks International
www.motorbooks.com

Automobile Inspections LLC
(Nationwide automobile appraisal & inspection services, including classic cars)
Hartford, CT
www.automobileinspections.com

Classic Auto Appraisals (Evaluation of Classics, Street Rods, Antiques, Competition Cars, Exotics, Commercial Vehicles and Hand Crafted Vehicles).
www.autoappraisals.com