07-12-2005, 06:08 PM
From the Clark's Garage online repair manual for 944's (with which 968's share sunroof parts amongst others) "This is a very common problem area. Over time, the motor slip clutch torque tends to increase." It is this increase in torque that causes the sunroof gears to strip. The Clark's Garage repair pages for the sunroof can be found here : Clark's Garage Sunroof Troubleshooting and are comprehensive for problem solving. This procedure is cobbled together from information found there.
What you'll need do to this :
- A torque wrench capable of very low settings (5 NM or 3.7 Ft-Lbs.)
- A 21mm deep socket for the torque wrench
- A 13mm 'slimline' style wrench
- Another 13mm wrench or socket
This is the procedure :
1. Lower your sunroof to the closed position. This is the position where the sunroof is held in place against the roof of the car.
2. Remove the carpet cover from the drivers side wall under the rear hatch glass. This piece is held on with one snap at the rear, four somewhat fragile plastic plugs along the top, and is glued to the wheel well. It's not necessary to remove the glued part to expose the sunroof motor. It is not necessary to remove the plastic cover that's revealled underneath, as the nuts you'll need are visible through a round hole. What you should see should match what's in the owner's manual directions for manual sunroof operation.
3. Check the current torque setting : the factory spec is 6 NM +/- 0.5, Clark's page recommends 5 NM, choose a setting you're comfortable with and use the 21mm deep socket and your torque wrench on the large nut you found under the carpet. Pulling the handle of the torque wrench towards the rear of the car will slowly raise the sunroof. It should take less than 6.5 NM to move the large nut. If it does take less, stop here as you don't need to adjust anything.
4. Adjust the torque : To adjust the torque you'll need to loosen the two 13mm nuts on top of the 21mm bolt. The outer nut is (obviously) holding the inner nut in place. Use a slimline-style wrench to hold the inner 13mm nut in place and your other 13mm wrench (or socket) to turn the outer one. Make the adjustment to the inner 13mm nut, tighten the outer 13mm nut and check the new torque against the 21mm nut.
It takes a lot of wrenching to fully raise the sunroof, so you shouldn't hit the upper limit while testing. If you do simply change direction, pushing the wrench towards the front of the car, to lower the roof. The sunroof will operate normally wherever the arms are posiitoned once you are done : from released to closed with the key in the ACC position, and from closed to open in the RUN position. To make adjustments to the travel of the sunroof arms requires adjustments to the gears or the micro-switches, which is covered in the Clark's Garage link above.
That's it. I wish I'd done that three years ago, before I busted my sunroof gears and had to do it anyway. I'm not certain about the naming of the 'slimline-style' wrench. That's what Snap-On Web Page called theirs, I actually used a flat-piece-of-metal disposable wrenches in the correct size that I had lying around. If you have a better equipped workshop than mine you may have another means turning one nut while holding another.
What you'll need do to this :
- A torque wrench capable of very low settings (5 NM or 3.7 Ft-Lbs.)
- A 21mm deep socket for the torque wrench
- A 13mm 'slimline' style wrench
- Another 13mm wrench or socket
This is the procedure :
1. Lower your sunroof to the closed position. This is the position where the sunroof is held in place against the roof of the car.
2. Remove the carpet cover from the drivers side wall under the rear hatch glass. This piece is held on with one snap at the rear, four somewhat fragile plastic plugs along the top, and is glued to the wheel well. It's not necessary to remove the glued part to expose the sunroof motor. It is not necessary to remove the plastic cover that's revealled underneath, as the nuts you'll need are visible through a round hole. What you should see should match what's in the owner's manual directions for manual sunroof operation.
3. Check the current torque setting : the factory spec is 6 NM +/- 0.5, Clark's page recommends 5 NM, choose a setting you're comfortable with and use the 21mm deep socket and your torque wrench on the large nut you found under the carpet. Pulling the handle of the torque wrench towards the rear of the car will slowly raise the sunroof. It should take less than 6.5 NM to move the large nut. If it does take less, stop here as you don't need to adjust anything.
4. Adjust the torque : To adjust the torque you'll need to loosen the two 13mm nuts on top of the 21mm bolt. The outer nut is (obviously) holding the inner nut in place. Use a slimline-style wrench to hold the inner 13mm nut in place and your other 13mm wrench (or socket) to turn the outer one. Make the adjustment to the inner 13mm nut, tighten the outer 13mm nut and check the new torque against the 21mm nut.
It takes a lot of wrenching to fully raise the sunroof, so you shouldn't hit the upper limit while testing. If you do simply change direction, pushing the wrench towards the front of the car, to lower the roof. The sunroof will operate normally wherever the arms are posiitoned once you are done : from released to closed with the key in the ACC position, and from closed to open in the RUN position. To make adjustments to the travel of the sunroof arms requires adjustments to the gears or the micro-switches, which is covered in the Clark's Garage link above.
That's it. I wish I'd done that three years ago, before I busted my sunroof gears and had to do it anyway. I'm not certain about the naming of the 'slimline-style' wrench. That's what Snap-On Web Page called theirs, I actually used a flat-piece-of-metal disposable wrenches in the correct size that I had lying around. If you have a better equipped workshop than mine you may have another means turning one nut while holding another.
