The 944 is equipped with a glass hatch that is surrounded by an aluminum frame. This frame is supported by 2 gas pressurized struts (attached at each rear corners) and two hinges at the front. When the hatch is in the closed position the strut place "reward" tension on the glass. Over time this tension cause the glass to be pulled loose from the forward portion of the frame. This will ultimately break the seal and cause water to enter the vehicle. Ive heard of cars having this problem in less then a year. Shame Porsche, shame.
I contacted several local glass shops but none were willing to work on it. Every shop said to buy a new hatch from the dealer! With very little to loose (its my brother-in-laws car) I decided to attempt the repair myself. For the investment of a couple hours and less then $10.00 in materials its well worth the effort. The hatch now fits correctly and should last for a long time given proper treatment.
The affected car is a 1985 1/2 944 with unknown mileage (the speedometer was previously replaced). This car has the "rode hard put away wet " look and feel. The glass had separated from the forward frame and caused a 2-3mm gap. My B-I-L had sealed the gap with silicone to minimize the leak.
ProcessWarning (disclaimer)! This repair is performed at your own risk. Dont blame me if you break or crack the glass. I felt it was worth the risk (not my car) to attempt the reseal. If you are not willing to accept the idea of buy a hatch DO NOT attempt this.
Because the frame will most likely be bent the hatch will need to be removed. Begin by removing the rear portion of the headliner. Mine was held in with 7 screws. Remove the forward portion of the hatch seal by pulling it towards the rear of the car. Carefully peal back the headliner (it is held in place by the seal) to gain access to the allenhead bolts retaining the hinges. This car had the head-liner cut to get to the screws, dont try this at home. Loosen all 4 bolts but do not remove. Remove the retaining clips on the hatch struts and disconnect the wires for the defroster and wiper motor if equipped. With the help of an assistant, (have them support the hatch while the bolts are removed) remove hinge bolts and washer plate under the bolts. Disconnect the hatch struts and CAREFULLY lift the hatch off the vehicle. Pretty strait forward.
Stand the hatch on its tail on a soft surface (an old sleeping bag works very well) and support it so it can not fall over. With a flat blade screwdriver carefully pry the trim loose from the inside. Start from one side and work slowly. Its comes off fairly easily but dont get in too big of a hurry. The frame is soft and will bend easily. Continue working your way across the frame till the trim is removed.
Now determine if the frame is bent along the end where the glass has pulled loose. This example was bent very noticeably at each hinge point.
To straighten the frame I used 2 1/2inch extensions, a big pair of channel lock pliers and a 3/4inch piece of wood. See drawing .
While holding the fixture in place squeeze the frame back into position. Ensure that the extensions do NOT contact the glass and check you progress repeatedly. Its helpful to have another set of hands to support this fixture.
When you are sure you have the frame straight and the glass fits to your liking. Gently pull the frame away from the glass and thoroughly clean the seal. Apply of generous bead of Silicone based sealant. I used DAP® brand 100% Silicone rubber sealant (black) from my local Ace hardware store. Dont worry about making a mess as it can be easily scraped off with a razor blade when cured.
After the silicone has cured remove the clamps and trim away any excess silicone.
Reinstall the trim to the front of the hatch. You may need to do some tweaking to the trim piece if it was damaged (twisted etc) during removal. After getting the trim started I seated it using light blows from a dead-blow hammer. A rubber mallet would work equally well.
Get your buddy to help reinstall the hatch. It is helpful to have a small screwdriver to center the hinges with the bolt holes. (Why are these back seats so small, or maybe Im just too fat?) Loosely tighten the mounting bolts so the hatch can be adjusted to fit. When you are happy with the alignment tighten the bolts and temporarily reconnect the struts, your buddy will start to complain about it getting heavy (blah blah blah). Reinstall the head-liner and connect the wiring. When reinstalling the hatch seal pay attention to the forward corners. On this car the seal didnt contact the hatch and had to be "persuade" to fit correctly. It had not been seated correctly for quite sometime as the carpet was soaked! Im guessing Ill be putting in a new seal before too long.
You may want to leave the struts disconnected for several days to give the silicone time to completely cure.
If youve got a pulled out hatch give this repair a try. Its not difficult and is a lot cheaper then replacing the hatch.
Pelican Technical Article:
944 Rear Hatch Glass Repair
Porsche 944 (1983-89)