CORRECT DOMESTIC SPRING APPLICATIONS FOR ALL 1957 MODELS ARE AS FOLLOWS:
THE CORRECT SHOCK ABSORBERS APPLICATION FOR ALL 1957 MODELS ARE AS FOLLOWS:
NOTE: Export shocks may be used on cars where the owner feels that stiffer shocks would be more desirable for his particular use.
WHEEL ATTACHING BOLTS
For Fabricast Aluminum Brake Drum
Supplementing the new aluminum fabricast brake drum article covered in Red Band Service Letter, Dealer No. 203, we are stressing the importance of using the correct wheel to hub bolt with the aluminum drum.
The design of the drum is such that if regular production wheel to hub bolts are used only a 1/4″ of the bolt would thread into the drum and the possibility of stripping the threads is present. Therefore, under no circumstances should any bolts other than Gr. 5.812 Part #1179472 be used on models equipped with the fabricast aluminum brake drum. This bolt is approximately 1/4″ longer than those used with the Motor Wheel and Buick Drums and should not be used with the Motor Wheel and Buick Drums because it may bottom against the Parking Brake Strut if installed on the rear wheel assembly.
BALANCING FRONT WHEELS
Recent tests conducted at Engineering revealed the proper distribution of wheel balancing weight is a very important factor in reducing or eliminating front wheel shimmy tendencies. It has been proven especially on power steering equipped cars that front wheels requiring more than three (3) ounces of static balance weight the weight should be split by placing half of the required weight on each side (inboard and outboard) of the wheel rim; otherwise, steering wheel shimmy may be introduced by a dynamic unbalance condition.
SPRING TRIM HEIGHTS
The spring trim height dimension for 1957 models are as follows:
On a car having service miles, the front and rear spring trim dimensions should be within the following limits, with car at curb weight. See Figure 61.
Front Spring Within + or – 1/4″
All Convertibles – 4 1/4
All other Models – 4 1/2
NOTE: When checking new cars add 1/4″ to above front trim dimensions.
Rear Spring Within + or- 3/8″
49-69 – 6 1/4
48 – 5 3/4
41-43-63 – 5 5/8
46C-66C-56C-76C – 5 1/4
46R-66R – 5 1/8
53-73 – 5 1/2
56R-76R – 5.0
NOTE: When checking new cars add 3/8” to above rear trim dimensions.
INSTALLING UPPER CONTROL ARM ASSEMBLY
It is important when installing a complete upper control arm assembly from Parts stock on 1957 cars that the following procedure be observed:
The correct location of the inner shaft is determined during assembly at the factory, then the shaft is wired to lock it in this position; however, in order to do this it is necessary to rotate the shaft 90° so that the shaft mounting holes will be in a position to suitably wire them. It is important, therefore, when installing the assembly on a car that the wire be removed and the inner shaft rotated 90° in the proper direction so that it is positioned correctly for installation.
To aid the mechanic to properly position the shaft for installation, a white daub of paint is applied on the shaft between the mounting bolt the upper control arms, difficulty may be encountered in obtaining correct caster adjustment.
1957 BUICK WHEELS
To provide an even greater safety factor in preventing the tire from rolling off the wheel, Engineering has made a design change in the 1957 wheel outer bead seat. Fig. 63 shows a view comparing the new wheel which has a hump-type bead seat on the outboard side of the rim and the early 1956 wheel. This new design provides a tighter tire fit; therefore, it will be slightly more difficult to demount and mount a tire on this wheel. For this reason it is most essential to use only conventional bead-breaker type equipment when servicing this type of wheel and tire assembly. Do not hammer or attempt to use tire irons or damage to the tire beads will result.
Also, it has been brought to our attention that some late 1956 B.O.P. Assembly built Buicks have been equipped with this new type wheel. These new wheels can be identified by removing the hub cap and noting the groove or depression in the wheel rim as indicated in Figure 63.
Caution: When mounting a tire on this new type wheel, it is imperative to apply mounting soap around the beads for ease of mounting and prevent damage to the beads.
BALL JOINT SERVICE INFORMATION
1957 – All Series
To give you a better picture on the function of Buicks ball joint type front suspension the following information is submitted. See Figure 64.
The upper ball stud is pr0loaded at all times in the socket to a load of approximately 250 pounds which eliminates looseness at this point, adjusts the assembly for wear and provides friction in the joint to dampen wheel shocks. The lower ball stud carries the vehicle weight which keeps the assembly constantly loaded and the ball firmly seated in the socket. This is true even when the wheel enters a “chuck” hole in the road because the moment the wheel is suspended in air the coil spring exerts a downward force tending to keep the ball seated in its normal load carrying position.
The amount of front wheel rock observed during an inspection of the front suspension when the front of the car is raised depends on the location in which the jack or lift is placed. If the front end is raised by placing a lift or jack to bear on the lower control arms of the front suspension, the following conditions exist:
- The downward load of the vehicle weight (all of which is carried by the lower ball joint through the lower control arm and coil spring) is removed, thereby relieving the joint of the designed load which prevents lateral movement.
- Within the lower ball joint, the stud is free to move within a design clearance between the top of the ball and the spherical socket. This clearance is held as closely as production tolerances will permit and still not bind the ball. If all the looseness in the lower ball joint were removed, the lower metal retainer would contact the underside of the ball and cause a binding condition which would result in scoring and would tend to prevent the wheels from returning to the straight ahead position after making a turn. This designed looseness within the ball joint, together with a varying degree of normal wear, could result in a maximum of 1/4″ lateral movement, measured at the circumference of the tire, when weight is relieved, which is considered normal. Within this limit of movement no corrective measures are required, nor should be taken; however, if it exceeds 1/4″, the lower ball joint should be replaced.
NOISE IN FRONT SUSPENSION
Several dealer product reports have been received stating that a creaking or grinding noise can be heard in the front suspension while making turns, braking, or while traveling over a wavy road. In some cases these noises have been traced to front springs not being properly positioned in the spring seat on the lower control arm assembly.
FRONT END ALIGNMENT
Caster, camber and toe-in adjustments cannot satisfactorily be checked or changed on the 1957 Buick unless the front and rear of the car are held to a specified trim height. We have always pointed out the importance of maintaining trim height during front end alignment. However, many times a “passable” job was performed without proper attention being paid to this procedure. With the introduction of the 1957 front suspension, proper trim heights become more important to the point where even a “passable” front end alignment cannot be performed unless strict attention is given to – this problem. It has been found that for any given change in front trim height on our present car, caster changes three times as much as on past production. Under no circumstances should the front end alignment on a 1957 Buick be judged unsatisfactory unless the car either handles improperly or shows excessive tire wear. A front end alignment is not necessary and should not be made merely to bring a car into the recommended ideal alignment specifications as shown in Figure 65. Unsatisfactory handling and/or excessive tire wear are the real indications of incorrect front end alignment.
NOTE: All measurements except toe-in to be taken with pins installed. Toe -in should be checked and brought to specification with the car at running height.
Taking a very practical approach to this problem brings out the following facts:
Caster does not effect tire wear but does effect handling.
Camber, if excessive to the point of having twice that recommended, will have some effect upon tire wear; however, it effects proper handling.
Toe-in is important for satisfactory tire wear and proper handling, and may be easily checked and corrected without the use of special equipment.
In view of this, the greatest service to the owner will be performed if proper toe -in is maintained on his car and the caster and camber left as is.
Caster and camber settings are made during assembly by installing appropriate thicknesses of shims between upper control arm shaft and frame brackets at both front and rear attaching bolt locations. Both round and slotted shims are used; however, at least one slotted shim will be found at each upper location. Both types come in thicknesses of .060″, .080″ and .100″ with the .080″ shim copper plated for identification. Due to limited accessibility and torque requirements (90 to 100 ft. lbs.), it is strongly recommended that the upper shims not be disturbed unless absolutely necessary.
Service shimming is to be performed at the lower control arm shaft-to-frame attaching bolts. Under no circumstances, however, should any one stack of lower shims exceed .160″ – serious damage to the ball joints and malfunctioning of the anti-dive feature will result. If a satisfactory correction cannot be made by shimming at the lower control arm shaft, it will then be necessary to shim at the upper control arm shaft-to-frame-bracket attaching bolts. However, here again, under no circumstances should the total thickness of shims at any one location exceed .380″. If proper alignment cannot be attained without exceeding the .160″ at the lower location and .380″ at the upper location, the suspension parts should be replaced or the frame straightened. Parts should be replaced or the frame straightened if the ball joint assembly shows evidence of damage.
SHIM REPLACEMENT PROCEDURES
Shim removal and replacement procedures will vary according to the equipment and facilities available. However, the following procedure will produce satisfactory results:
- Inflate all tires to their specified pressures.
- Locate car properly on the front end equipment.
- Place a 3/8″ square pin 3-21/32″ long between the frame and front lower control arm at each front wheel as shown in Figure 66, making sure that the pin is standing vertical and not leaning. Use sandbags or other suitable weight when necessary to hold car down on pins.
Use sandbags or suitable weights when necessary to hold the car down on the pins.
Due to play between the lower control arm shaft attaching bolts and holes in the frame cross member, it is possible to change caster approximately 3/8° without effecting an appreciable change in camber, merely by shifting the lower control arm assembly . It is therefore recommended that when shimming at the lower shaft, only one end be loosened at a time to maintain the original position of the shaft. Service shims to be used at the lower control arm shaft attaching bolts are available under Gr. 6.172 Part #1179204 .040″ and #1179205 .120″ thick. It is extremely important to use only Buick-supplied shims as others may not be hard enough and therefore will not be dimensionally stable. Because of the possible movement of the lower control arm assembly, it is extremely important that the lower control arm shaft attaching bolts be tightened to the specified torque whenever they are disturbed.
To shim at the upper control arm bolt location, use the following procedure:
- Disconnect negative cable from battery.
- Force the lower edge of the inner fender skirt toward the wheel so that the front shims and bolt head can be reached from the engine compartment. (See Fig. 68)
loosen the nut. A 13/16″ open end wrench ground to fit between the head of the bolt and the frame bracket can be used in place of a wedge.
- Disconnect negative cable from battery.
- Disconnect generator from engine and move generator and bracket assembly back as shown in Figure 71.
LOWER CONTROL ARM SHIM SELECTION
To assist in determining the proper shim to use at the lower control arm bolt location, the following information may be used as a rough guide. Further experience obtained through aligning more cars will give each mechanic additional skill in the selection of shims and locations.
Adding .040″ (one shim) at the front of the lower control arm changes:
Caster- approximately 1/4 o toward negative
Camber and toe – virtually no change
Adding .040″ (one shim) at the rear of the lower control arm changes:
Caster – approximately 5/16° toward Positive
Camber – approximately l/8° toward Negative
Toe – toward toe-out
Adding .040″ at both front and rear of the lower control arm changes:
Caster – virtually no change
Camber -approximately 3/16° toward Negative
Toe – approximately 3/16″ toward toe -out
NOTE: The addition or removal of shims (front or rear) will produce a change in the same direction (plus or minus) whether done at the upper or lower arms.
Adding shims to front of arm moves caster toward Negative.
Adding shims to front of lower arm moves caster toward Negative.
The special wrench, 1-6771, acts as a lever when using the torque wrench, 1-1313, as shown in Figure 8. With this particular wrench, it is only necessary to pull 45 ft. lbs. on the wrench to apply 100 ft. lbs. on the upper control nut.
The following formula may be used to figure the required torque to pull when using a torque wrench other than 1-1313 or those listed in the table.
Torque wrench dial reading= 100 ft. lb. x length of torque wrench in feet +/- by length of torque wrench in feet+ 1.67 feet.
UPPER CONTROL ARM SHIM SELECTION
To assist in determining the proper shims to use at the upper control arm shaft bolt locations the table shown in Figure 73 may be used. Again, experience gained through repeatedly performing the operation will further assist in selecting the proper shim and location.
ALIGNMENT CORRECTION PROCEDURES
The following alignment correction procedure is given in order of preference: i.e., if the preferred step (a) does not give sufficient adjustment, step (b) may be necessary. If steps (a) and (b) do not suffice, then step (c) may be necessary.
It is imperative to check and correct toe-in following any caster or camber adjustment.
NOTE: This procedure changes camber or caster using two separate operations. Experience, however, will show that both camber and caster may be changed at the same time in one operation. Always remember – adding or removing the same amount of shims from both the front and back bolts changes camber only ; adding or subtracting shims from the front location changes caster only ; adding or subtracting shims from the rear location changes both caster and camber.
UPPER CONTROL ARM SHIM TABLE
Approximate camber changes shown are based on the same shim thickness being added or removed from both the front and rear bolt locations.
Approximate caster changes shown are based on the shim being added or removed from the front bolt location. The shim change can be made at the rear location however camber will also be changed.
- To correct excessive negative camber:
- If shims have been installed at lower control arm shaft front and rear locations, remove equal thicknesses at both front and rear to obtain adjustment. Tighten bolts to specified torque.
- Loosen upper shaft bolts and remove equal thickness of slotted shims front and rear to obtain adjustment. Torque bolts 90-100 ft. lbs.
- To correct excessive positive camber:
- Loosen lower shaft bolts and add equal thicknesses of shims front and rear (limit total thickness to .160″) to obtain adjustment. Tighten bolts to specified torque. Recheck caster and adjust if necessary.
- Loosen upper shaft bolts and add equal thicknesses of slotted shims both front and rear (limit total to 4 shims and thickness to .380″) to obtain adjustment. Torque bolts to 90-100 ft. lbs. Recheck caster and adjust if necessary.
- To correct excessive negative caster:
- If there are shims installed under the lower arm front attaching bolts – remove enough of these to obtain proper setting. Tighten bolts to specified torque.
- Loosen lower arm rear attaching bolts and add sufficient shims (Limit total shim thickness to .160″) to obtain proper setting. Tighten bolts to specified torque. Recheck camber and adjust if necessary.
- Loosen upper arm shaft bolts and remove enough slotted shims from front location to bring caster into adjustment. Torque bolts to 90-100 ft. lbs.
- Loosen upper arm shaft bolts and add enough shims (limit total to 4 shims and thickness to .380″) at rear location to bring caster into adjustment. Check camber and readjust if necessary. Torque bolts to 90-100 ft. lbs.
- To correct excessive positive caster:
- Loosen lower arm front bolts and add sufficient shims (limit total thickness to .160″) to bring caster into adjustment. Tighten bolts to specified torque.
- If there are shims installed under lower arm rear bolts, remove enough shims to make correction. Tighten all four bolts to specified torque. Check camber and correct if necessary.
- Loosen upper arm bolts and add sufficient slotted shims at front location (limit total to 4 shims and thickness to .380″) to obtain adjustment. Torque bolts to 90-100 ft. lbs.
- Loosen upper arm bolts and remove enough slotted shims at rear location to obtain adjustment. Torque bolts 90-100 ft. lbs. Check camber and adjust if necessary.
- To correct toe alignment:
- Toe-in or out corrections are done in the conventional manner as described in Par. 7-17, sub. par. 3 of the 1956 Service Manual, with this additional Caution:
When toe adjustment is complete, the lower surface of the tie rod ends must be parallel to the surface of the road; otherwise, binding may result on severe bumps or brake stops, and the tie rod adjusting clamps must be turned approximately 45 6 forward from their true down position so that they do not cause interference with the frame.
- Toe-in or out corrections are done in the conventional manner as described in Par. 7-17, sub. par. 3 of the 1956 Service Manual, with this additional Caution:
NOTE: Buick Engineering does not approve bending front suspension parts to correct the alignment. If specifications cannot be obtained, new parts must be installed.
LOWER CONTROL ARM BOLT CHANGE
Lower control arm inner pivot shaft attaching bolts used in early production were the 280M type with a maximum torque specification of 55 to 65 ft. lbs. These bolts are identified by the 3 marks on bolt head. See Figure 74.
Starting with car serial numbers listed below by assembly plants, 300M high tensile strength bolts (7/16 – 20 x 1 3/4) and nuts were used with hardened plates under bolt heads. These bolts are identified by 6 marks on bolt head and should be torqued at 70-80 ft. lbs. Do not torque the 280M bolt more than 65 ft. lbs.
On Flint built cars only, Serial Number of jobs between 01011141 and 01019422 were equipped with 300M bolts (7/16 – 20 x 1 1/2) and hardened plates. If any job with a Serial number between those listed above requires shimming at lower control arms, new bolts (7/16 – 20 x 1 3/4) group 6.172 #1180338 and nuts Gr. 6.172 # 1180335 should be installed.
Identification of bolts may be determined by using a mirror and observing bolt head markings, or identifying the car by serial number. All jobs having serial numbers higher than those listed below by assembly plants will have the late type 300M bolts (7/16 – 20 x 1 3/4) nuts and hardened plates:
Plant – Vehicle Identification Number
- Flint – D1019422
- South Gate – D2008960
- Linden – D3010505
- Kansas City – D4011733
- Wilmington – D5011213
- Atlanta – D6006418
- Framingham – D7004627
- Arlington – D8008005
If, for any reason, the 280M bolts are to be replaced, the 300M bolts Gr. 6.172 #1180338, nuts Gr. 6.172 #1180335 and the hardened plates Gr. 6.172 #1180406 should be installed and bolts torqued to 70-80 ft. lbs.
Whenever installing these new parts, it is important to position the plate with rounded corners against the frame. If sharp corners with burrs were placed against the frame, the rough edges may prevent equal distribution of bolt clamping force and result in loss of torque when these surfaces become flattened due to wear.
Placing a jack under the control arm inner pivot shaft adjacent to the attaching bolts, will facilitate removal of old bolts and plates without changing alignment an appreciable amount. Upon reassembly, a drift should be used in one of the bolt holes to aid realignment of parts to original location. NOTE: Replacement of these parts should be made at only one location at a time; doing so should eliminate the necessity for realignment or shimming.
REAR SPRING INTERFERENCE
Some of the recent dealer product reports describe an interference between the rear suspension springs and the rear cross-member extension (inner parts of the frame side rails adjacent to and out board of the springs). In order that a sufficient clearance be provided at this location, the upper and lower spring clamps must be positioned so their holes are concentric with the large coils in the spring. The correct clamp-to-spring eye relationship is shown in Fig. 75. (view is “inside” the coils, looking down upon the lower clamp).
Please note that the portion of the clamp flange with the higher radius of curvature follows closely the contour of the eye in a counterclockwise direction from a point near the end of the wire for slightly over 180°. The depressed or “cup” portion of the clamp also follows the contour of the eye
Due to the method of manufacture, one end of the spring wire will have a straight length of 0 to .9 inch. (Shown by dotted lines in Fig. 75.) The clamps, however, will fit as shown.
In the event a spring must be turned to eliminate its interference with the frame, and before the spring is tightened to the axle and rear spring cross-member, a check must be made to see that the clamps are positioned properly.
GRILLE MOUNTING CHANGE
We have been advised by Engineering that the radiator grille mounting has been changed slightly to improve the alignment of it with the front bumper.
The change consisted of eliminating the mounting brackets at the outer ends of the radiator grille. See Figure 76.
With these brackets removed, the grille can be moved up or down to allow more adjustment so that no interference will be encountered between bumper and the grille.
CHANGING COLOR ON MOLDING
In BPS 2.418 an article was published on the method of repairing the. Tangerine accent stripe. We have now been advised that in addition to the Tangerine accent stripe, green and blue colors are also being made available. In the event repairs or changes in the color of the accent stripe are desired, the colors are available under the following Dulux Mixing numbers:
Tangerine – 56505H
Green – 56515H
Blue – 56516H
In the event factory painted moldings are to be refinished, the following procedure should be observed:
CAUTION: If the Tangerine accent stripe had been previously repainted with Dulux Air Dry 56505H, it will first be necessary to apply two medium coats of Dupont Bleederseal before the finish coat is applied because the mixing formula #56505H is a bleeder.
- Mask molding.
- Lightly rub existing painted finish with fine steel wool to dull gloss.
- Clean surface to be painted with Dupont Prep Sol or equivalent to insure removal of road film or silicone polish and wipe dry with clean rag.
- Repeat steps 2 and 3 using another clean rag after second Prep Sol treatment.
- Spray Dulux Air Dry.
- On any sizeable areas that are bare to the base metal, clean thoroughly by scrubbing with pumice or equivalent. Rinse thoroughly and wipe dry with a clean rag. Do not allow the water to evaporate on the part. On this same area, spray one coat of Dupont Preparakote Alkyd type primer surfacer. Allow Preparakote to dry four (4) hours before applying the top coat.
The flat rate time to change the color is as follows:
First Section of Molding Refinished .4
Each Additional Section .1
Complete Refinish – Both Sides 1.1
NOTE: The center pillar molding on all four-door models and the rear door rear molding on models 53 and 73 will not be considered a section by themselves. These moldings will normally be refinished at the same time an adjacent molding is refinished.
The time for the First Section of Molding includes: Masking and papering around molding, sanding, mixing color coat, refinishing and cleaning spray gun. The time for Each Additional Section includes: Masking and papering around molding, sanding and refinishing.
The Parts Department will stock only the Tangerine Moldings for all service replacements and when replacements are needed on cars which have the Blue and Green Moldings, it will be necessary to repaint the Tangerine Moldings to match those on the car. The part numbers for the Blue and Green Moldings which were added to the Parts Book on March 1, will be replaced by the Tangerine Molding and only the Tangerine Molding will be shipped for these part numbers.
REAR BUMPER EXTENSION MOLDING REWORK
1957 Estate Wagons
When replacing the Rear Bumper Extension Molding, Group 7.833 Part 1175217, on some of the first production built 1957 Model 49-49D-69 Estate Wagons, it may be necessary to reshape both ends of this molding. Due to variations in the ends of the Rear Bumper Face Plate used on the Estate Wagons, the ends of this molding were reshaped on some of the early production cars. If there is an interference between the molding, as supplied for service, and the rear bumper face plate ends, the molding should be reshaped as shown in Figure 77.
PLASTIC REMOVAL FROM MOLDING
To protect the painted stripe on 1957 sweepspear moldings stocked by the Parts Department, a plastic covering is used. As a precaution against damaging the painted stripe on the molding when removing the plastic covering, it is suggested to rub a blunt tool along the edge of the molding to break the plastic loose as shown in Figure 78.
Then the plastic can be peeled off very easily with the fingers. See Figure 79.
CAUTION: Do not slide tool or instrument under plastic or damage to the painted stripe may result.
REAR BUMPER CLEARANCE
Several dealer Product Reports have been received stating that excessive clearance exists between the rear bumper ends and the rear quarter panel extension. The clearance at this location should be 3/4″ to 1″ and the gap should be parallel within 1/16″. See Figure 80.
This gap is necessary to allow a crunch area in which the bumper may absorb shock without causing damage to the rear quarter extension.
MOUNTING TUBELESS TIRES
Supplementing the 1957 wheel article covered in BPS 2.415, dated November 9, 1956, this is to stress the importance of lubricating the tire bead and bead seat on wheel flange before mounting a tire on a 1957 wheel.
Because of the newly added hump-type bead seat on safety rim wheels, the tire bead may hang-up on this seat during tire installation until inflation pressure is sufficient to force the tire bead against the outer flange. In such instances, the tire bead will remain seated against the hump until extremely high inflation pressure (over 40 lbs.) forces the bead against the outer wheel flange bead seat. See Figure 81.
The sudden seating of tire bead happens with such great force that the pressure of the repercussion may inflict possible serious damage to the eyes or face. For this reason, the tire service man should never stand over the tire when inflating it. It is suggested to use an extension gauge such as the Schrader 1020 extension gauge with clip-on chuck, and stand back from tire for maximum safety. See Figure 82.
Normally, inflating the tire to approximately 40 lbs. will seat the beads properly. If 40 lbs. pressure will not seat beads properly, deflate, lubricate hump on wheel with mounting compound or soap solution, center and re-inflate. After beads have seated properly, reduce pressure to recommended operating pressures.
LOOSE BALL STUD IN LOWER CONTROL ARM
We have received a few dealer product reports which state that the lower control arm ball studs and upper control arm inner shaft bushings are found to be loose in 1957 cars. Looseness of these parts has been noticed when the car is raised on a hoist with support under the “A” frame instead of the tires. For your information, the lower ball joint is designed to have approximately 1/16″ movement of the stud in the socket and should be considered normal when checked in the above manner.
Also, the upper inner shaft bushings are the same as past models and have a slight amount of looseness in them when the weight of the car is resting on ”A’ ‘ frame and not on the tires. This is to be considered normal.
When the weight of the car is on the wheels, the lower ball stud will be forced into the socket, except in extreme cases when slight reversal of the loading may occur to cause the ball to unseat. However, the upper ball stud assembly must be preloaded at all times and any sign of free play between the stud and socket under any condition should be corrected by replacing the part.
UNDERCOATING BUICK CARS
It has been brought to our attention again that some service personnel are carelessly applying undercoating in certain areas where undercoating should not be applied.
Since this material is inflammable when we t, extreme caution should be exercised when applying undercoat to the parts of a car.
DO NOT PUT UNDERCOATING ON ANY OF THE FOLLOWING: Muffler – Tail Pipe – Lower Shift Controls – Body Mounts – Between Frame Members And Under Body Causing A Direct Acoustical Short – Balancer – Brake And Wheel Cylinder – Air Conditioner Parts – Rubber Hoses Or Any Moving Parts.
Undercoating should only be applied to the following parts:
Complete body floor pan, under all fender surfaces, bottom of rocker panel (Note: Do not plug drain holes), and bumper gravel shield. Make sure all sheet metal joints are sealed, light coat permissible on gas tank; however, upper end of filler neck and cap to be avoided.
NOTE: Any overspray on moving parts, pipe fitting, fan belts, exhaust system, air conditioner parts, etc. must be removed.
HOOD OPERATING ROD BINDING
We have received several dealer Product Reports which state that the hood latch operating rod is binding in an open position (not allowing the hood latch to completely lock). Therefore, bumps will jar the hood loose, causing the hood to open to the safety latch. This binding condition may be eliminated by increasing the size of the hole in the operating rod bracket to 1/4. See Fig. 83 In a few cases these brackets have been bent, causing them to bind. Therefore, it is important that the bracket be perpendicular to the operating rod.