Removing and Repairing the Sill Board


Figure 1

Ash Frame

The sill boards on a Morgan form the foundation of the body frame. Along with the door rocker, they join the front and the rear halves of the frame together. It is of paramount importance to regularly examine and maintain the boards. With modern sealants and underseal, rot can be kept at bay. Preventing decay in the sill boards will also help protect the door rockers, hinge post and latch post joints. Since 1986, the manufacture of Morgans ash frames has included immersion in Cuprisol for several hours. This should prevent it from rotting for a long time.

If you are considering purchasing a Morgan manufactured before 1986, it would be wise to thoroughly examine the sill boards before parting with your cash. Pay particular attention to the condition of the underside rear ends. Prod them with a sharp instrument to check for softness, which will indicate rot. If the owner allows you, peel back the trim and horse hair covering the top of the sill boards. This will reveal the conditions of the joints connecting it to the rest of the frame.


Sill Board Underside

If you look at the underside of the sill board in Figure 2, you will observe an area overlapped by the front wing. The rear of the wing is not only secured here by several screws, but it offers protection to the latch post joint. Ironically water, attracted by cohesive forces, seeps in between the narrow gap of the steel and wood. The water is restricted from drying out and is absorbed by the end grain of the latch post. The area cut out of the sill board, where it is joined to the latch post, also has end grain exposed. Morgans manufactured before 1986, only had underseal protecting the area. As the car chassis flexes, so does the sill board, which allows water to enter the joint as described above. This not only causes the sill board and latch post to rot, it can also involve the rear end of the door rocker and the latch block. The relationship of these joints is illustrated in Figure 1.

Regular maintenance of the sill board underseal will help protect this area. Take care to always remove loose underseal and thoroughly dry the timber, before applying a good quality new product. Also regularly apply Waxoyl around the beading between the front wing and the body.

Figure 2

Sill Board underside


Sill Board Dimensions

If the car you are restoring has severely rotten sill boards, the dimensions shown in Figure 3 should hopefully be of some use. They were taken from the off side sill board of my own car. It can be seen from Figure 2, that the underside of the board had suffered from a little decay, but was intact enough to allow a template to be made. However, the nearside board was so rotten , I needed the offside template to help make the nearside one.


Figure 3

Sill Board

Disconnecting Essential Components to Free the Frame from the Body


Before releasing the frame from the chassis: .

DISCONNECT THE BATTERY. In early Morgans the fuel line lays alongside the main battery cable, as illustrated in Figure 4 . They are fixed to the nearside sill board and covered in flammable trim. If you accidentally short circuit the main cable, you are likely to burn the car and yourself.

REMOVE THE FRONT WINGS AND BONNET. The grill, cowl, and cowl box will also be removed along with the front wings

REMOVE THE REAR WINGS.

REMOVE THE THRESHOLD PLATE AND INTERIOR TRIM COVERING THE SILL BOARD.

REMOVE THE SEAT BELTS AND FIXING BOLTS ON THE WHEEL ARCH AND LEAF SPRING HANGERS.

REMOVE THE LEAF SPRING HANGER COVERS. They are secured by

REMOVE THE WIRING FROM THE REAR OF THE DASHBOARD. Also remove the wiring from the flasher units mounted on the scuttle top rail

REMOVE THE WIPER ASSEMBLY FROM THE SCUTTLE.

REMOVE THE SCREWS SECURING THE BULKHEAD TO THE FRAME. (see Figure 5).

REMOVE THE SCREWS FIXING THE REAR TRANSMISSION TUNNEL TO THE FLOOR AND INNER PLYWOOD PANEL . (see Figure 5).

REMOVE THE SCREWS FIXING THE INNER PLYWOOD PANEL TO THE BATTENS ON THE FLOOR. It will lighten the frame if the inner plywood panel is removed.

The fuel pipe and the cable connecting the positive battery terminal to the starter solenoid are fixed to the nearside sill with 'P' clips. The rear wiring loom is fixed to the offside sill and the rear bottom rail with 'P' clips also. These three items can be left attached to the frame when lifting it from the chassis. However, Check that the positive battery terminal has been disconnected from the battery cable.

DISCONNECT THE BATTERY CABLE FROM THE STARTER SOLENOID and withdraw it through the bulkhead. (see Figure 4).

DISCONNECT THE PIPE FROM THE FUEL TANK and place a bung in the tank outlet to prevent the escape of dangerous fumes.(see Figure 4).

DISCONNECT THE FUEL PIPE FROM UNDER THE BONNET and withdraw it through the bulkhead.

DISCONNECT THE REAR LOOM NINE WAY CONNECTOR, then pull off the lucar connectors securing the wires to the handbrake microswitch and the fuel tank sender unit.(see Figure 4).




Figure 4

Electrical and fuel tank diagram






Removing Panels to gain access to the Sill Board

The frame can be lifted from the chassis with the bulkhead, fish tails and quarter panels, still attached to the frame. However to gain access to the sill boards it will be necessary to remove the quarter panels, threshold plates and fish tail panels. See Figure 5

During the lift it can be advantageous to leave the scuttle in place to help maintain the shape of the frame. It will however, have to eventually be removed if the door rocker or hinge posts require attention.

Take care not to damage the quarter and fishtail panels when removing them from the frame. The flanges of the panels are secured by pins and screws. Sometimes it is difficult to remove them without damaging the edges of the panels, particularly when they are corroded. It is useful to make templates of the panels before removing them, although their final shape and fit will ultimately depend on the shape of the frame. If the sill board is severely rotten, the quarter panel and fish plate will most probably be corroded as well.


Figure 5

Preparation to lift frame


Releasing the frame from the Chassis

Ten coach bolts and two hexagonal bolts secure the ash frame to the chassis. Two hexagonal bolts passing through the steel latch post brackets also help secure the frame to the chassis. They are indicated by a green 'B' in Figure 6, whilst the position of the coach bolts are indicated by 'CB' in red. A bitumen damp course is fitted between the chassis and the ash frame. An effective waterproof damp course must be fitted when refitting the frame. A steel leaf spring hanger cover is screwed to either end of the inner panel and the floor. Remove the screws and the seat belt anchorage bolt from each of the leaf spring hanger covers.

REMOVE THE TEN COACH BOLTS SECURING THE FRAME TO THE CHASSIS. Note that the rear two coach bolts on each side of the frame pass through a small grooved sill at the back of the chassis. See Figure 7

REMOVE THE STEEL LATCH POST BRACKET BOLT SECURING THE FRAME TO THE CHASSIS See Figure 6

LIFT THE ASH FRAME FROM THE CHASSIS.

WHEN THE FRAME IS CLEAR OF THE CHASSIS FIX TEMPORARY STABILISER STRUTS ACROSS THE FRONT OF THE SCUTTLE FRAME. See Figure 6


Figure 6

Main chassis mounting points


Removing the Sill board

Support the frame on a clean flat surface and remove any remaining panels. If any of the panels remain on the frame, it will not be possible to complete an assessment of its condition. Careful examination of the frame will reveal which components need replacing and how much new timber is required.

Removing both sill boards will leave the frame in a very unstable condition. If the door rockers have rot in them, the rear and the front of the frame are likely to part company. For the Morgan factory or an experienced agent, this will not be a problem, because they will possess jigs and standard parts. For the amateur, it is safer to work on one side of the frame at a time.

Examine both sill boards and remove the most decayed one first. On an old car it is usually the nearside one. When all of the panels have been removed, there are only ten screws fixing it to the frame. There are five screws under the rear wheel arch see Figure 7. These will most probably be the most difficult to remove. They certainly were on my car. Luckily, if you are removing the board, it is usually because it needs replacing. Therefore, cutting around the screws, or drilling out the heads, will be fine. However, be careful not to damage the plywood inner wall of the wheel arch. It is not usually prone to rot and as far as I know is made of marine ply. If it is rotten, it will be easy to replicate with new marine plywood.

Figure 7

Rear wheel arch mounts

A rabbet joint connects the rear of the sill board with the laminated wheel arch. See (Figure 8) The two screws connecting connecting this joint will most probably also prove difficult to undo. If so, carefully drill them out. When fitting new sill boards, offset the position of the new screws and replace all of them with stainless steel ones.

Figure 8

Removing the Sill board

The screw at the base of the latch post usually suffers from the same problems as those mentioned above, particularly if the latch post is rotten.

There are only three screws forming a butt joint between the sill board and the rear end of the door rocker. This is because the rocker curves upwards away from the sill board and inwards towards the scuttle post. These three screws are usually easier to remove. If the frame is on a firm flat surface, heavy downward pressure on the screw driver will help stop it from slipping out of the slots on the screw heads. A simple rabbet joint connects the sill board to the scuttle frame post, with one screw.


Replacing the Frame on the Chassis.

Remove rust and repaint the chassis before re-mounting the frame. Severe corrosion should be cut out new steel welded in its place. Trial mount the frame, checking for a perfect fit against the bulkhead, before drilling the mounting holes. Paint the frame with a good quality exterior primer and top coat. Fit new damp proof courses and remount the frame.

Figure 8

Removing the Sill board




BrakeSwitch