GROUP 12 – 1956 BUICK FRAME AND SHEET METAL
12-1 CHECKING ALIGNMENT OF 1956 BUICK FRAME
Checking Alignment of 1956 Buick Frame and Suspension Members
When a 1956 Buick frame has been damaged by accident the following procedure may be used to check alignment of the frame, and the alignment of the chassis suspension members with the 1956 Buick frame. This procedure should be used to check alignment after repairs to frame have been completed.
Checks are to be made with 1956 Buick frame assembled with power plant, body, etc. and car resting on wheels. The car should be placed on a clean floor that is reasonably level. Both sides of the front ends of the frame must be the same distance from the floor; the same condition must exist at rear end of 1956 Buick frame. Where points are to be extended to floor by use of a plumb bob, it is desirable to attach clean pieces of paper to floor with tacks or tape so that the points can be clearly marked. Apply brakes or block wheels so that car cannot move.
- Using a plumb bob, extend the following points to the floor and mark where point of plum bob touches floor, as shown in figure 12-1.
- A and A1 at point of grease fitting in front ends of control arm shafts.
- B and B1 at center of front ends of lower pivot pins.
- X at center of hole in front flange of frame front cross member, on centerline of 1956 Buick frame.
- D and D1 at center of rear axle shafts.
- E and E1 at center of forward bolts attaching rear bumper.
- F and F1 on side rails just forward of rear axle housing, holding plumb line fiat against side mils.
- G and G1 at each side of torque tube flange.
- Move car out of the way. Using a chalked line, draw lines on the floor through the following points: A and A1, B and B1, D and D1, F and F1.
- Divide the distance between F and F1 and mark the center point Y on line F-F1. Draw frame centerline through points X and Y.
- Measure diagonal distances A to E1 and A1 to E. If these diagonals are not equal within 5/16″ the frame is bent.
- Measure the distances J and J1. If these are not equal within 1/8″ a lower control arm is bent.
- Measure the distances K and K1, which will be equal within 3/16″ if rear axle is properly aligned with frame. Points G and G1 should be equally distant from vehicle centerline X-Y. If distances K and K1 are not equal within 3/16″ and points G and G1 are equally distant from centerline, a bent rear axle housing or torque tube is indicated. If points G and G1 are not equally distant from centerline, look for misalignment of engine in the 1956 Buick frame.
Checking Alignment of 1956 Buick Frame Only
When a 1956 Buick frame has been damaged by accident and the power plant, body, etc., are removed, the measurements shown in figure 12-2 or 12-3 may be used to check for alignment of frame members. The procedure should also be used to check alignment after repairs to frame have been completed.
The 1956 Buick frame must be solidly supported on suitable stands so that the pilot holes in both side rails are exactly at distance indicated from a straight and level work surface. Note that alternate pilot holes of different size and location may be found.
12-2 1956 BUICK FRAME REPAIRS
Straightening and Welding
In case of frame distortion resulting from an accident it is permissible to straighten or weld the 1956 Buick frame if the distortion is not excessive.
Heat can be applied without materially weakening the steel, provided this is kept below 1200°F. This is a deep cherry red when viewed in subdued daylight, as in an average shop. Heat in excess of 1200°F. will weaken the metal structure and lead to eventual failure in service.
Replacement of 1956 Buick Frame Members
If a frame front cross member is very badly distorted as a result of a front end collision, replacement is advisable because its rigid box construction makes proper straightening very difficult. Since the front suspension members are mounted on the frame front cross member, front end alignment will be affected if the cross member is not in perfect alignment.
The front end and rear cross members, rear spring support cross member, and a number of braces and brackets are available for service replacement. The old members may be removed from the 1956 Buick frame by cutting the attaching rivets and welds, after removing other parts or assemblies to allow working space.
When installing new frame members use hot rivets since they can be properly driven with hand tools. Cold driven rivets are not recommended because they cannot be securely driven with hand riveting tools. In places where hot rivets cannot be installed it is permissible to use finished bolts snugly fitted in reamed holes. Use lockwasher with bolts and draw nuts up tight. Weld a new member to adjacent members in the same manner that the replaced member was welded.
After installation of any new frame member check the 1956 Buick frame for proper alignment as described in paragraph 12-1. After any repairs or replacements in front end of frame be sure to check front wheel alignment (par. 7-17).
12-3 DESCRIPTION OF 1956 BUICK SHEET METAL
1956 Buick Front End Sheet Metal Assembly
The 1956 Buick front end sheet metal assembly consists of both fender skirts and tie bar, hood latch mounting panel, radiator grill, radiator pan, radiator core and mounting strap, fan shroud, horns and brackets, and lower gravel deflector.
All parts are joined together in an assembly that may be removed and installed as one unit, or the separate parts may be replaced without difficulty. The front end of the sheet metal assembly is supported and stabilized by attachment of the fender skirts to the frame side rails by means of bolts provided with rubber shims similar to body mountings. See figure 12-5. The rear ends of front fenders are attached directly to the body cowl.
1956 Buick Hood, Hinges, and Latch Mechanism
The 1956 Buick hood panel is of one-piece construction which is strengthened and held to shape by front and rear transverse reinforcements of stamped sheet steel. The front end is also strengthened by a brace attached to the panel under the hood ornament to the center of the front reinforcement.
The 1956 Buick rear end of the hood is attached to the body cowl on each side by hinge assemblies which permit the front end of hood to be raised, alligator type. A heavy coil spring connected between each hinge assembly assists in raising the hood, and holds it in the open position. The springs exert a downward pull when hood is in closed position.
The 1956 Buick front end of hood is locked down by a dovetail bolt on hood which engages a lock lever in the latch mounted on a panel of the front end sheet metal assembly. Proper tension on the latching parts is maintained by a spring and retainer which surrounds the dovetail bolt (fig. 12-4).
The hood is unlocked by lifting a release lever located beneath radiator grille frame. A safety hook mounted on the hood must then be pulled forward before the hood can be raised.
12-4 1956 BUICK FENDER, BUMPER AND HOOD ALIGNMENT INSPECTION
The 1956 Buick hood, front fenders and bumper must be aligned with each other on every car to take care of slight variations in form and dimensions of the individual parts. Sheet meta1 parts stamped in a given set of dies will vary somewhat in form and dimensions due to variations in the hardness of different batches of sheet metal, which cause the stampings to spring in varying amounts when released from the dies.
The 1956 Buick hood and front fenders are properly aligned during the installation at the factory; however, some readjustment may be required after a car has been shipped or has been in service for some time. This is because sheet metal parts may take a different “set” as a result of vibration and shock incident to shipping or operation during the break-in period. In judging the need for readjustment it must be understood that exactly uniform fit and spacing cannot be obtained on all cars of a given model.
IMPORTANT: After any work on front end sheet metal assembly which changes fender position, be sure to check aiming of headlamps as described in paragraph 10-49.
Hood Noises or Panel Flutter
Squeaks or grunting noises in the hood when driving over rough roads do not necessarily indicate misalignment of hood and fenders. These noises may be caused by metal contact at some point where clearance should exist or by worn or dry hood bumpers.
If the hood squeaks, check with 1/16” thick feeler all around the hood for clearance at radiator grille frame, fenders and cowl. If an edge of metal is making contact at any point where clearance should exist a bright metal spot will usually be found. Such spots may be depressed by spring hammering to provide clearance.
A grunting noise in the hood is usually caused by dry rubber bumpers or cowl ledge lacing. Lubricate all rubber bumpers on fender rails and cowl with Lubriplate (Finch Refining Co., No. 110). To correct a persistent case of squeaking or grunting where hood top panel contacts ledge lacing, even when lubricated, cement a 1/16″ thick strip of felt to panel where the lacing makes contact.
To prevent hood panel flutter, the rear end of hood panel must have firm contact with the rubber lacing attached to cowl ledge. The hood may be raised or lowered by adjustment at hinges. If cowl ledge lacing is loose, recement it in place and make sure that all fasteners are properly installed.
Before deciding upon any adjustment to correct hood or fender misalignment it is advisable to check tightness of all attaching screws and bolts, since a true picture of correction requirements cannot be obtained when the sheet metal is loose and free to shift.
After all parts are properly tightened inspect fender and hood alignment (subpar. c) and hood alignment (subpar. d). Make all inspections before performing any adjustments because an adjustment at one point will usually alter alignment at other points. The preliminary inspection should determine the adjustments that will produce the best overall alignment of hood and fenders at all points.
Fender and Hood Alignment at Front Doors
With front doors closed there should be no metal-to-metal contact between doors and rear ends of front fenders. Check for clearance at frequent points, using a strip of fibre or other soft material 1/32″ thick. The spacing between rear end of front fenders and the shoulder on front edge of doors should be approximately 1/8″, and fairly uniform from top to bottom.
Before making any adjustment of sheet metal to provide necessary clearance at points mentioned, first make sure that front doors are properly aligned in the body openings. If fender and door panel surfaces are not reasonably flush, correction may be made by adding or removing shims between the fender and the cowl panel.
Where spacing between end of front fender and edge of door is objectionably uneven from top to bottom it may be necessary to adjust the shims between frame rails and the sheet metal supports on front fender skirts.
1956 Buick Hood Alignment Inspection
When closed and locked, the hood should bear firmly against the rubber bumpers on lower hood latch mounting panel and the rubber lacing attached to the cowl ledge.
A clearance of approximately 1/8″ should exist between each side of hood and the fender, and the spacing should be fairly uniform from front to rear. Along the sides, the hood and fender contours should be in reasonably close horizontal alignment.
A clearance of approximately 1/8″ should exist between the rear edge of hood and the shoulder of cowl panel, and the spacing should be fairly uniform from side to side.
Raise and lower the front end of hood slowly several times to check for proper alignment between the dovetail bolt in hood and the latch on sheet metal panel. Dovetail bolt should enter the opening in latch without any side strain or other interference. As hood is raised and lowered, observe whether the rear edge contacts the body cowl due to improper adjustment of the hood guide bracket and roller pad.
12-5 1956 BUICK FENDER, BUMPER AND HOOD ADJUSTMENTS AND REPLACEMENTS
1956 Buick Front Fender and Bumper Adjustment
If the front end of the sheet metal assembly is too high or too low, resulting in objectionably unequal vertical spacing between front fenders and doors, it will be necessary to change the shims located under the supports on front fender skirts. Adjustment of shims also may be required if the front end of the sheet metal assembly is tilted to right or left so that proper alignment of hood and fenders cannot be obtained by hood adjustment.
At the point where each front fender skirt support is attached to frame rail a rubber shim is placed on each side of the frame rail top flange, with a steel washer 1/8″ steel shim and tubular spacer placed to control compression of the rubber shims as the bolt is tightened. Two steelbestos shims are placed between the 1/8″ steel shim and the f ender skirt. When additional shimming is required one or more extra steel shims .060″ thick are placed between the steelbestos shims and the fender skirt. See figure 12-5.
The front bumper attaching bolt holes in frame front cross member are slotted vertically to permit raising or lowering either end of the bumper for proper alignment with adjacent parts. Special shims are available for insertion between the bumper back bar and frame cross member to move bumper forward as may be required for proper alignment with adjacent parts.
Removal and Installation of 1956 Buick Hood Springs
- Support 1956 Buick hood in extreme up position, preferably by chain fall if available.
- Remove hood springs with remover and installer J-6325 by performing the following steps. See figure 12-6.
Step A. Insert Remover and Installer J-6325 through loop in forward end of spring with bend of tool approximately one inch from loop. Pivot tool on hinge. Apply force as indicated by arrow, unseating spring from groove and move tool into groove. See figure 12-6 Step A.
Step B. Apply force as indicated by arrow and remove spring. See figure 12-6 Step B.
- Replace hood springs by inserting tool J-6325 through loop in forward end of spring. Pivot tool on hinge and apply force as indicated by arrow and loop spring into groove. See figure 12-7.
Removal and Installation of 1956 Buick Hood Assembly
- Support 1956 Buick hood in extreme “up” position.
- Place folded rags under the rear corners of the hood to prevent possible damage to the fenders.
- Remove 4 hood hinge to body bolts.
- Lift hood and hinge assembly from car.
- To install, reverse the above procedure.
NOTE: No adjustment is necessary when R&R hood and hinge as an assembly.
1956 Buick Hood Adjustments
- If rear of 1956 Buick hood sets high (does not pull down to cowl), add a shim between the hood and hood hinge bracket at front bolt.
- If rear of hood sets too low, add a shim between the hood and hood hinge bracket at the rear bolt.
- Close hood with hinge-to-hood bolts just snug and align hood.
- Raise hood carefully taking care not to misalign and secure hinge-to-hood bolts.