Hiding the heart of our '49 Buick Roadmaster Sedanet is the hood. It has evolved over the years from the "butterfly" on early cars, to the side-opening, the "alligator" (hinged at the cowl), and reverse-opening front-hinged hoods; each type compatible with the car's overall design theme and unique unto itself.
The side-openers used in the '40's by Buick and Packard had inside knob-controlled releases. You could release one side and leave the other side locked, then lift the open side and set the hood support in place to work on that side of the engine. If you wanted the whole hood off of the car, just release both sides and lift off, giving full access to the engine compartment.
In this article, I will describe the construction and function of 1948 and 1949 Buick (all series) hoods. The hood is one-piece construction, strengthened and held to shape by two transverse reinforcements on its underside. On Series 40 (Specials), the reinforcements are tubular and are bolted to the hood panel. The bolts provide a limited amount of adjustment in changing the hood panel width. On Series 50-70 (Super and Roadmaster), the reinforcements are channel shaped and welded to the hood panel, and do not provide any means to alter hood width.
The hood is supported by rubber bumpers and lacing at the cowl, as well as being locked in place by two gooseneck hinges on each side, mounted on the front fender rails. On the '48's, a pilot pin on the hinge engages a pilot hole in a pilot plate on the hood, which insures that the hood sits in the correct position on the hinge. On 1949 Series 50-70's, the pilot pins are on the hood and the pilot plates are on the hinge assembly. The hood fastener on either side locks the hood to front and rear hinges at the same time. Once one side is locked, the other side can be raised and kept in place by a support hinged in the center of the cowl. With both sides unlocked, the entire hood can be lifted from the car.
HOW IT WORKS: On 1948 models, each side of the hood is locked to the hinges by a hood-mounted fastener which includes a rod with two loops. These engage hooks on the hinges as well as an outside recessed handle that activates the fastener rod. When the front end of the handle is pressed inward, the hood becomes unlocked from the hinges and can be raised using the rear, projecting end of the handle.
HOOD HINGES AND FASTENERS: On 1949 Series 50-70's, a self-locking hood fastener mechanism is built into the hood assembly. Unlocking is controlled by release knobs below the instrument panel, which activate the unlocking cables. Separate release knobs unlock each side of the hood. Pulling the knob rearward makes the hood unlock and raise high enough to allow further lifting of the hood by hand. Releasing the knob lets it move forward into its seat by a spring, without affecting the hoods position. To close and lock the hood, simply lower it onto its unlocked fasteners with its pilot pins on their holes in the pilot plates, then push down on the side of the hood, causing the hood fastener latches to engage and lock the hood. A hood fastener is mounted on each hinge, and front and rear fasteners unlock simultaneously with a releasing rod attached to both fasteners. This rod has a cable connected at one end to the release knob, and is anchored to the rear hinge at the other end. The cable goes over a pulley that is mounted on a housing, which slides on the fastener rod. When the release knob is pulled to the rear, the pulley housing hits a shoulder on the rod, making it move rearward, unlocking the front and rear fasteners. Once released, a spring pulls the pulley housing and cable back into position.
HOOD NOISES: If the hood squeaks, take a 1/16" feeler and move it all along the hood edge, checking for clearance. If you find an edge making contact where there should be clearance, there will usually be a bright spot in the metal. Press any such spots out with a spring hammer. On 1948 models, check to see if the rubber coating is worn off the bumpers on the cowl and underside of the hood hinge plates. This can cause a metal-on-metal squeak, and can be remedied by replacing the worn bumpers and adjusting to correct height.
A grunting noise is usually caused by rubber bumpers and cowl ledge lacing that has become dry. These should be lubricated to stop the noise. If the noise persists after lubricating, a 1/16" strip of felt can be glued to the panel where the lacing is making contact.
SHEET METAL ALIGNMENT: If the hood is misaligned, before making any adjustments to the hood or front end sheet metal, first check all the screws and bolts to make sure they are tight. Check: a. Radiator mounting strap to mounting bracket on the frame; b. Radiator mounting strap side braces at the strap and frame side rails Use 10-15 ft lbs torque on these bolts. Excessive torque will distort the right hand side mounting strap on the 1948 model); c. fender skirts to mounting strap and grill frame; d. fender skirts to frame; e. fender to fender skirts and grill frame; f. fenders to support brackets at the body; g. hood hinges to fenders.
Once all front end sheet metal is securely fastened down, take the following steps to inspect everything. Remember that an adjustment at one point will affect the alignment at another point, so a preliminary inspection will reveal the overall effect of any adjustment you might think of making.
ADJUSTING HOOD HINGES & FASTENERS ON 1948 MODELS:
Pilot plates on the hood top panel reinforcements must sit flat and tight against the hinge plates when the hood is locked. When either side of the hood is closed, the hinge pilot pins have to line up with the holes in the pilot plates so that they can go in smoothly. Any looseness in the hood hinges, or any misalignment of the pilot pins will cause the hood to sit incorrectly when closed, and opening to be awkward. The hood and hinges should be adjusted to allow a uniform clearance of approximately 3/32" between the hood and the fenders on each side, and the contours should match. Check this clearance with a feeler gauge.
Check the contact between the hood plates and hinge plates by raising one side of the hood with the opposite side locked, and inspect the hinges on the locked side. Both hinge plates should be in firm contact with the hood reinforcement plates, as in Figure 2-A. In view 2-B, adjusting is needed as described below. Check the opposite side hinges the same way.
With one hood side locked, raise and lower the opposite side several times to check the alignment of the pilot pins with the pilot plate holes. If the alignment is not correct, the hinge will bind and appear to raise and lower with the hood. To determine the direction of misalignment, clean the grease from the pilot pins and holes, then coat the pins with chalk. The chalked pin will be heavily marked on one side if it is not properly aligned with the pilot hole. If the marking is on the inner side, that's usually acceptable, providing that the hinge doesn't bind and raise with the hood. Check the opposite side the same way.
If you find that the hinge and pilot plates are not making proper contact, first check the hood fastener rod clips, making sure they are tight. The clip bolts are large enough to allow the fastener rod locking tension to be increased by loosening the bolts and moving the clips up as far as possible, then tightening the bolts securely. You might have to bend a hook on the hinge up or down to ensure equal contact of the hooks on the fastener rod loop.
For best locking condition, make sure the pilot plate contacts the hinge plate along its inner edge first, checking to ensure that the hinge plates are flat. Also, check the pilot plates on the hood panel reinforcements and if they are distorted, straighten them with a hammer or a pry bar. It may be necessary to bend the pilot plate down along the inner edge of the opening to make contact along the inner edge. Be sure that the bent-down edge is straight front-to-back, insuring full contact with the hinge plate.
WHEN THE HOOD IS DOWN AND LOCKED.
The hood fastener handle must seat firmly and fully into the recess of the fastener handle body on the hood when the hood is down and locked. The correct adjustment of the fastener plate allows the fastener arm to snap past center against the stop lug on the fastener plate in locked position, with the maximum free travel available for the initial release of the handle, made possible by the operating rod slot in the hood fastener handle. In its initial release position, the handle has to extend out far enough to allow a firm pull for unlocking the hood.
If the hood fastener handle does not fully seat into the recess in the fastener body, it could be because of some kind of interference between the sides of the handle and the body, such as a burr on the handle side, or distortion of the base when it was assembled to the hood panel. With the hood open and the handle in its locked position, check the clearance between both sides of the handle and the body with a 1/32" feeler gauge. If the clearance is less than 1/32" on the sides, make these adjustments:
1. Loosen the two center stud nuts that fasten the handle body to the hood panel
2. Put 1/32" metal shims on each side of the handle at the center and close the handle, which will force the sides of the handle body outward.
3. Tighten the two center stud nuts securely, then take out the shims. Re-check the clearance to see if it is sufficient on each side of the handle to let it operate freely.
If the hood fastener handle has good clearance but does not seat in the handle body as described above, loosen the three bolts that attach the fastener plate to the hood, allowing the plate to be moved forward or backward. The plate must be shifted forward slightly if the fastener locks correctly but the handle does not lock securely (past center) allowing the handle to snap out of its recess and unlock the hood. Tighten the plate, attaching the bolts securely. This adjustment is needed if the the hood becomes unlatched when driving the car on a rough road.
If the guide pin on a hinge is not aligned with the hole in the pilot plate, or if there is unequal spacing between the hood and the fenders along the side, the hinge will have to be shifted to correct the alignment and spacing. Before you shift the hinge, be sure to determine the effect this will have on the spacing at the cowl and doors, so that the hood will have equal spacing in these locations.
The bolt holes in the hinges are slotted to allow front and back adjustments. To shift the hinge, loosen the attaching bolts that extend through the fender rail, make the required change in its position, then re-tighten the bolts.
If the hinge needs to be adjusted inward toward the centerline of the car, place a flat bar between the fender rail and the hinge plate and bend the hinge inward slightly as shown in figure B. To adjust the hinge outward from the centerline, insert a bar through the opening in the hinge under the plate and bend it outward slightly, as shown in figure C. When bending the hinge outward, keep in mind that a light contact on the inner side of the pilot pin is okay, but the pin should not bind in the pilot hole. If this adjustment of the hinge inward or outward doesn't result in correct pilot pin alignment, or if it causes the spacing between the hood and fenders along the sides to be incorrect, the width of the hood will have to be adjusted as follows:
On Series 40 only: Hood width adjustment is provided by an elongated hole in each of the hood pilot plates and an oversized hole in the reinforcement brace for the bolts that attach the tubular hood reinforcement and brace to pilot plate. To adjust the hood width at either end of the front or rear reinforcement, loosen the attaching bolts, push in or pull out the edge of the hood to change the width as required, then tighten the bolts securely.
On Series 50-70: The hood reinforcements are welded to the hood pilot plates, so adjustment for width is usually not necessary. Rarely, it might be necessary to move a hinge out further than advisable to bend it, so it might be necessary to install spacer washers as needed between the fender rail and the hinge under the fender.
After securing proper contact of pilot and hinge plates, or while shifting the hinges to align the pilot pins as above, check the hood and fender contours along the sides of the hood. Hood and fenders should be in close alignment as shown in figure E-A. If the hood is obviously higher than the fender as shown in figure E-B, it can be corrected by lowering the hood hinges on the fender rail. Some vertical adjustment is possible with the oversize bolt holes in the fender rail, but in some cases it might be necessary to remove the hinge and elongate the bolt holes in the fender rail with a round file, so that the hinge can be lowered. When lowering a hinge, it might be necessary to bend up the ends of the bumper on the underside of the hinge plate, but don't bend it so far that it will not support the hinge plate. This can allow the hinge plate to contact the small flange on the inner edge of the fender rail. Lowering the hinge decreases the space between the hood and the fender. Don't reduce this space to less than 3/32" as measured with a feeler gauge. If the horizontal flange of the fender rail will not permit the hinge to be lowered far enough, bend it downward with a hammer and punch on either side of the hinge.
In some cases, it might be necessary to cut a notch in the turned-up edge of the fender rail to ensure proper clearance under the hinge plate. When adjustment is completed, the hinge plate must rest on the bumper, and not on the fender rail. The bumper should be bent downward enough to support the hinge plate. When the hood rubs the corner of the fender on the hinge side when the hood is raised, even after all of the above adjustments have been made, the clearance between the pivot ends of the front hinges and the underside of the fender metal should be checked. If this clearance is much more than 1/8", adjustment of the hinges to raise the pivot ends will give additional clearance between the hood and fender when the hood is raised.
ADJUSTMENT OF HOOD HINGES AND FASTENERS, 1949 Series 50-70
To achieve proper fit of the hood at the grill, fenders and cowl, and proper operation of the hood hinges when opening and closing the hood, there must be correct positioning of the front fenders and correct adjustment of the hinges in relation to the fenders and to the hinges themselves. For the hood fasteners to operate properly, there must be correct adjustment of the fasteners on the hinges, correct adjustment of the fastener releasing rods, and synchronization between the front and rear fasteners, as well as correct adjustment of the release cables.
Check the front fenders to ensure that all the fastenings are tight, and that the fenders are in proper alignment with the front doors. With the hood closed and locked, check the clearance between the fenders and the sides of the hood using a feeler gauge to full depth. The clearance should be about 3/32" on each side, and fairly uniform from front to rear. Lateral adjustment of the hinges will correct improper clearance.
Alignment of the hood and fender contours must be checked. If the hood is too high or too low, the hinges can be adjusted vertically.
Clearance between the nose of the hood and the radiator grill should be approximately 5/64" and fairly uniform from side to side.
The clearance between the rear edge of the hood and the shoulder of the cowl should be approximately 1/8" and fairly uniform from side to side. Any improper space may be corrected by hood adjustment, but uneven spacing might require an adjustment of the radiator mounting strap.
With the opposite side locked, open and close each side of the hood to check alignment of the pilot pins with the holes in the hinges. Straighten the pins if the lower ends are out of line. If there is any binding when the pins are fully within the holes, the hinge will have to be adjusted.
With the opposite side of the hood raised, check each side to ensure that the hood panel reinforcements are firmly against the hinge pilot plates, both front and rear. If there is any gap between the reinforcement and the hinge pilot plate, the hood fastener will need adjustment.
ADJUSTMENT OF HOOD HINGES, Series 50-70
There are slotted mounting holes on the hood hinges, allowing vertical adjustment. These holes are oversized in width to allow some forward and backward adjustment. To move in either direction, loosen the hinge mounting bolts.
If it is necessary to adjust a hood hinge side to side to change the hood-to-fender clearance, the spacer washer thickness between the hinge and the fender rail can be changed. All hood hinges should be finally positioned so that the top surfaces of all four hinge pilot plates are level with each other and on the same plane. Use a straight edge to check the level between the front and rear hinge pilot plates on each side and readjust the hinges as needed to obtain full bearing of both plates against the straight edge.
On the fender rail lower flange under each hood hinge, there is an adjustable stop screw that bears against a rubber bumper installed in the hinge. These stop screws should be adjusted to provide a slight upward pressure on the hood hinges after all the hinge adjustments have been done. Adjust each stop screw individually until, with the hood down and locked, any shaking or looseness is eliminated at each hinge.
ADJUSTMENT OF HOOD FASTENERS AND RELEASE CABLE:
The hood fastener tension is not adjustable, because the latches are spring-loaded to make them automatically seek a firmly locked position. A slight amount of vertical adjustment can be made, due to the oversized holes for the bolts that attach the fasteners to the hood hinges. Ideally, the fasteners should be mounted as low in the hinges as the mounting holes will permit, unless this causes improper locking of the fasteners.
The hood fastener releasing rod is attached to the front fastener trunnion by means of check nuts on both sides of the trunnion. This way front and rear fastener adjustments can be synchronized to ensure that both fasteners lock simultaneously. When both fasteners are in full open position, the shoulder on the rear end of the releasing rod should just touch the trunnion of the rear fasteners. The hood release cables must be free of kinks and must be anchored firmly to the rear hood hinges. The cable sheaths must be securely fastened to the fender rail. When the fasteners are open and the release cable knob is pulled into its seat by the cable return spring, there should be 3" distance between the rear end of the cable pulley housing and the shoulder on the releasing rod. This distance can be made by adjusting the cable where it anchors to the rear hood hinge.
The Buick's system is more labor-intensive than the Packard's, but once these adjustments are made, they provide years of reliable service.
See you next month, and keep em driving!