Exterior: Hide Rear Wiper (Stealth Wiper Mod)

Written by: Chad "92StealthTT" Weiland

This is a mod for the rear wiper motor. It will reverse the direction of rotation of the wiper. So, you can put the wiper arm at the bottom of the window instead of straight up & down. Although this can be done with a 3000GT or a Stealth, it's probably more beneficial to Stealth owners. With this mod done, the Stealth owners can hide the wiper arm behind the spoiler. No more wiper arm sticking it's ugly head out at you. The car now has a cleaner, nicer look to it. It's also handy in that now, the wiper will push snow up & off the rear window instead of down and compacting it into the spoiler.

Getting to the wiper motor[edit]

Remove the interior hatch trim (upper liftgate). There are 2 phillips head screws to remove the hatch tanneau cover clips in the middle of the trim piece. And there are 2 more screws towards the front of the piece in the corners. Once those 4 screws are out you should be able to carefully pry the trim piece off. It's secured by clips along the perimeter of the piece. Just keep moving along, prying the trim off until it's free, and set it aside.
For a Stealth, you will also have to remove the rear wing (possibly on a 3kgt also, but I'm not sure on this). First, unplug the third brake light electrical connector located in the center of the hatch on the inside. The Stealth spoiler has a total of 4 10mm bolts to remove. 2 of them are directly beneath the center pier of the spoiler, and 1 each on the outer piers. Remove all of the bolts. Now, close the hatch, and carefully lift up the spoiler. There are 2 pegs on the outer piers that fit into holes in the hatch. You may have to wiggle the spoiler a bit to work those pegs loose. Set the spoiler aside, being careful how you handle it and where you set it so as not to scratch it.
Remove the wiper arm. Pop up the cover at the base of the arm, and remove the 10mm nut. Lift the wiper arm straight up & off of the wiper motor post. Set the arm aside.
Removal of the wiper motor. Pop the hatch back open. Unplug the electrical connector for the motor. Then remove the 3 10mm mounting screws. Then it will pull straight down & out.

Modifying of the wiper motor[edit]

Remove the case cover by taking out the 4 8mm bolts. Now you'll be able to see the guts of the motor/gearcase.
Remove the 2 snap rings circled in green above using a pair of snap ring pliers (or in a pinch you can use a couple of screwdrivers). Remove the pivot arm. Set these parts aside. Be careful not to lose any of these pieces while taking them off, you'll need them to re-assemble. The snap rings like to go flying across the room when you remove them, so a good idea is to place a rag over top of them as you're removing them, so if it does go flying, it's contained in the rag.
Now flip the motor/gearcase over, and remove the snap ring that holds the main gear in the case. It is circled in green in the pic below.
Tap on the shaft that you just took that snap ring off of to slide the main gear (white nylon) out of the bottom of the case.
Grind or file off the rivet head on the shaft of the main gear being careful not to damage the gear. Circled in blue in the below picture.

It should look like this once done filing/grinding.

Note the orientation of the two white "nubs" molded into the gear. In the stock position the arm mounting post is located between these two nubs.
Tap the shaft out of the main gear from the top(side with the arm mounting post).
Now we can reposition our start/stop point. Take the steel piece out of the gear that has the arm mounting post on it and rotate it 180° and drop it back into the gear. Make sure that the mounting post is now opposite the two "nubs". Re-insert the shaft thru the bottom of the gear, and tack weld the arm mount piece onto the steel shaft. Grind down your spotwelds so that once the arm is placed back on it, there will be no clearance issues. Clean up the gear using mild solvent or soap/water. Get all of those little metal filings out of there or they'll eat up your gearcase. If you don't have a welder, or don't have any friends with one, look up a local welding shop and have them do it for you. They'll probably charge you around $5. I would not suggest the use of JB Weld or Epoxy instead of welding as I don't think it would hold up.
Note the orientation of the "nubs" prior to welding it. The nubs need to be 180° from the arm post.

This picture shows the weld completed and the gear cleaned up ready to go back in.
Re-assemble the motor/gearcase in reverse order. Smear some of the grease from inside the case onto the gear's operating parts. Orientation of the main gear when you put it back in is not critical. Once you re-install it in the car, turn the motor on and let it cycle once or twice and it will find the correct start/stop points. Do this before putting the wiper arm or spoiler back on.
When you put the wiper arm back on (after you've already cycled the motor) place it in the down position.