Following is a DIY to possibly prevent the dreaded door check-strap clicking and eventually mounting bracket failure.
For those who haven’t experienced this common problem on the 993, let me give some background. Many 993 owners have commented on hearing clicking sounds as they open or shut their doors. This clicking progressively got worse and eventually they noticed the mount for the door strap had broken loose inside the ‘A’ pillar. This is the mount that you see in the door jam that is pinned to a curved arm that attaches to the door. This arm is part of the check-strap assy. It limits the door from opening too far and also keeps the door open a certain amount as desired. As you open the door, you can feel two spots of resistance or detents. As this check-strap assy. wears, in many cases, get harder and harder to overcome the detents. This in turn pulls and pushes at the spot-welded bracket inside the ‘A’ pillar, causing it to eventually break free. Somewhere in the design of the 993, Porsche thought two small spot welds would be sufficient in holding this bracket in place.
My car, a 1995 model, was getting harder and harder to open and close the drivers side door past the two detents. I had not heard any of the clicking sounds (I was lucky) as of yet, but wanted to prevent this from happening. I tried many lubricants with no improvement. So I decided to take the check-strap apart and see what can be done to give the bracket a chance to stay alive.
First you must remove the door panel from the door. There is a DIY on this wonderful website for this. You now will be able to see the back-side of the check-strap assy. through the opening where the stereo speaker was.
Remove the small spring clip that retains the pivot pin attached to the spot welded bracket in the door jam, at the ‘A’ pillar. This clip is on the bottom side of the bracket. Then remove the pivot pin. This pin is splined and takes some effort to remove. I used a small ball-peen hammer, and tapped it from the bottom up. Tape off any painted areas near by in case you slip with the hammer. Once the pivot pin is out, be very careful not to open the door much farther than it is now. Exterior sheet metal damage can occur. Remove the two bolts that fasten the check-strap assy. to the door. Use a short,10mm socket on a ratchet to do this. These are accessed inside the door jam area, between the door hinges. A small mirror will let you have a look at the fasteners. Once the bolts are out, you can remove the check-strap assy. from the inside of the door, through the speaker opening.
This is what the check strap assy. looks like:
There are four metal tabs that are bent over to retain the cover plate. Pry two of these tabs up 90 degrees, and pry up the other two just slightly. I used a small, thin, flat blade screwdriver and a hammer under the metal tab. This will enable the disassembly of the detenting mechanism. See picture below:
Once the tabs are bent up, remove the retaining
plate and degrease the entire assembly.
See pictures below:
The rubber tensioners act as a spring and provide pressure (preload) onto the steel rollers, which applies pressure to the sliding arm and its detents.
Once everything is clean, it will be easier to see the rubber tensioner orientation. The rubber tensioner needs to be trimmed to reduce the spring pressure on the steel roller. This is easily done with a new razor blade. Note that I trimmed the tallest surface with the rounded corners. See below picture:
Notice I trimmed as little as possible
as this is a sensitive adjustment (about .040”).
The following picture is a mock-up assembly
that illustrates the proper orientation.
I left the two bolts barely loose that attach the check strap to the door until I pressed
in the pivot pin. I did this because there is a vertical adjustment and was allowing
the check strap assembly to self-align itself before tightening up the two fasteners.
Another avenue to take was to grind down
the detents on the curved, sliding arm, but
Replace the door panel in the reverse order it was removed.
This is also a good opportunity to lube the door hinges and latch assembly.