996 Convertible Not Completing open or close

2003 996 Cabriolet � Violent Shaking Mid-Cycle / Not Reaching End Positions / Microswitch Question Hi all, I'm hoping for some guidance on a 2003 911 Cabriolet (996), ~104K miles. Issue: Convertible top doesn't complete open or close cycle. Convertible top operates, but at about 2/3 through the opening cycle it shakes violently Closing is normal No clicking/ratcheting just strong shaking/bouncing Additional Symptoms: Right side of clamshell sits slightly high when closed (left side is flush). I adjusted the rubber clamshell stops but had no effect. If I press it down on clamshell it springs back up Dash shows top NOT fully closed → windows don�t roll up. Same when opening → not recognized as fully open System never reaches a true �complete� state Latch / Mechanism Observations: Front latch latches and clicks normally Rear latch does not have a noticeable strong click, there is a faint click. I was able to access the rear latch mechanism: With the top almost fully open, I can manually move the mechanism and close the latch In partially/fully closed positions, it will not move manually (seems position-dependent) Microswitch: Located a 2-wire microswitch with a red plunger near the gearbox It does not appear to be fully actuated during normal operation What I�ve Done: Inspected linkage � nothing obviously loose Lubricated moving parts Checked and adjusted clamshell stops Observed actuator movement (appears limited) Reviewed Porsche service manual � calibration requires all microswitches to be functioning Question: Does this point more to: Rear latch not fully completing travel / not triggering microswitch? Slight misalignment (right side sitting high preventing switch activation)? Drive cable / gearbox not achieving full travel? Microswitch itself faulty? Notes: Assisting the top by hand does NOT reduce shaking System never reaches a confirmed �open� or �closed� state [size=13px] Likely Cause (my working theory): Top is not reaching final travel to actuate the rear compartment microswitch, so the control unit never sees a valid end position and the mechanism oscillates under load. -- Any insight appreciated � especially from anyone who�s dealt with rear latch/microswitch issues on a 996 cab.[/size] Thanks in advance.

Top in my �02 started acting a bit wonky exactly like your description and the first thing I did was check the hydraulic fluid level. It seemed a bit low so I emptied then refilled and that solved the problem. I did a bit of research and it looks like Pentosin CHF 11S is the stuff to get. It�s not expensive and is available at most auto parts stores, they may keep the larger cans of it in the back so ask if you don�t see it. It�s a little bit of work getting at the reservoir but nothing too terrible, it�s harder the get the liner for the top storage area back in place from what I remember. Just because I�m an idiot about things I used a brake bleeder pump to suck the old fluid out of the reservoir before topping it off. Probably not necessary and was a good bit of effort as the fill port is inconveniently located. Can�t quite remember how I refilled it but that was also a bit of a juggling act. Put some paper towels beneath to catch the inevitable spillage.

Thanks Gulfcoast911. I have worked on the hydraulics before and resolved the choppy operation by adding fluid. My current issue is the top doesn't complete the very last part of the open or close cycle. The clamshell is slightly raised (1/8") and I don't hear the rear latch engage when the top is down.

Sounds like the top needs to be calibrated� I don�t seem to have any threads saved on the subject but I recall seeing a number of them on the subject.