RCR40 MANUAL: Wiper Fitment

Temporarily mount your spider assembly with a few sheet metal screws, so you can easily remove and reinstall it during the process. Identify the post location on the spider assembly and drill the mounting hole to size. Invert the wiper actuator and insert into hole.

Mark the location where the actuator contacts the dash structure, as a reference for the next step.

Since the actuator mounts on the windshield frame on a GT40, not on the cowl, the angled bushings will not be used. Fabricate a couple of simple straight bushings as shown below. You may choose for the outboard one to be aluminum or plated steel for aesthetic reasons... your call. We chose aluminum.

Pic on left shows assembly order.

Now mark this profile on the dash structure using the previous mark as the reference for the post location. Cut out the actuator relief. Note, this hole will not be visible once assembly is complete, so it is not imperative that it be exact. It can be any shape you deem appropriate. It would be a good idea to outline the profile of the windshield frame, both inside and out, so you don't take any chance of cutting into material that is critical the windshield frame mounting. If you find that an under dash cross brace interferes with where you have decided to cut, that brace can be relocated by drilling out the rivets and remounting. Essentially, the hole must provide clearance for the actuator and a leg for tube entry.

Now, with the actuator clearance hole complete, determine your motor mounting location. A couple key things to keep in mind here:

1. You want to mount the motor such that the tube is as straight as possible in its approach to the actuator.
2. The motor must not have hard contact with anything, or motor noise will resonate through the chassis.

The actual placement of the motor will vary slightly depending on what hand drive your chassis is and what other items/accessories you have mounted under your dash. Place the motor under dash and string the cable drive up to the actuator.

Shift motor around to achieve desired approach angle to actuator. It may be necessary at this point to modify the tube leg of the cut hole to achieve optimal tube angle. Once you have determined desired location, mark and drill for mounting.

Mount the motor using the block insulator behind the motor. If there are any areas that are at risk of contacting the chassis be certain to insulate those areas too. Bend the drive tube to desired fit and mock fit.

Cut a small piece of tube for the back side of the actuator with some excess room for cable movement and install a vacuum cap.

System Wiring

 It is a good idea to run some wiring leads and label the wires now, as once the dash and other accessories are assembled, access to the plug may be a challenge.

Wiper system installed.

Manufacturer's notes on the wiper motor:

These notes are based on an article written by Tony Stafford, the founder of Stafford Vehicle Components who retired in Spring 2001, having spent his working life in the Motor Industry. 

1. Motor
The most popular type still available is the Lucas 14W. This is a two speed wiper motor, with self parking. Make sure you use the correct base pad and strap with the rubber covering, and the motor is not touching any part of the vehicle body to eliminate noise. 

2. Drive Gear
When the new motor arrives there is no threaded ferrule to take the drive tubes or internal gear. There are several gears to fit this motor starting with the number 95 which is stamped on the top round plate. This is giving the least amount of travel to the rack and wiper arms. The most travel gear is 130. The gear ratios go up in 5's so starting with 95, 100, 105 and so on, and most of these are still available. On the top of the gear plate where the number is stamped there is a drive peg welded in position. This is the only item which changes position throughout all the gears (e.g. welded in different positions on the top plate.). Obviously if this peg were welded to the centre of the plate there would be no travel at all, so the further the peg is positioned to the outer edge of the plate the more travel you get. With each gear come 2 washers and a circlip which retain the gear in to the motor. Always pack with grease in the gear area before refitting the top cover.

3. Wheel Boxes
The most popular wheel box size is 32 teeth on the inner drive wheel, and the ideal length of shaft from the inner face to the end of the splines is 2.5 inches. This allows for the thickness of material on fiberglass cars as the first spacer can be cut down in size allowing for varying thicknesses through the bulkhead where the wheel boxes fit. There is also a 40-tooth wheel box which will reduce the amount of wiper arm travel. If the car has a split screen then it is quite easy to fit what was called the clapped hands system. This is by turning one of the wheel boxes through 180 degrees (not applicable for the RCR40).

4. Drive Rack
When fitting a new system it is advisable to fit a new drive rack as this is one of the items that wears, resulting in the wiper arms having too much play.

5. Drive or "Bundy" Tubing Sets
It is far better to use the recommended wiper tubing from Lucas than to use copper tube as this can be noisy and wears very quickly on any bends. Wear of the drive tube causes friction that can lead to the motor burning out.

Bundy tube sets can be made up providing you give the supplier 2 dimensions. The first is the distance from the motor to the centre of the first wheel box hole, and the second the distance between the wheel box hole centres through the bulkhead. Obviously if there is a 3 wiper system then there is another dimension needed. Try to avoid sharp bends in the tubing, If you have to bend the bundy tube, an easy way to form the shape is to insert the drive rack into the tube before bending. This will keep the tube the correct diameter on any of the bends (very much like a plumber bends copper piping by inserting the spring). Always grease the rack liberally before inserting into the bundy tube.