DetroitMatt

Hi everyone,

This is my first post as I just purchased a new to me 1999 Carrera Cabriolet. It’s my first 911, so lots to learn here as I get it sorted. I have a clutch kit, LN IMSB and RMS on it’s way, but in the mean time, the convertible top is giving me grief and I could use some help here. I’m a pretty good mechanic, but convertible tops feel like sorcery to me. So many moving parts!

So when I picked the car up, the top was not working. It would almost want to open but just couldn’t quite make it. The back deck lid would come within inches of completing the cycle, but would get stuck there. It did close the opposite way thankfully, so I left the roof up until I was able to take it to my local independent Porsche shop to look at it. They fixed a stuck flap on one side and recalibrated the tip and $298 later it works now... sort of.

I normally have to open and close it a few times and after an attempt or two it does finally open or close as intended. It just takes a few tries, so it still isn’t working perfectly yet, although better.

I’m noticing three main issues:

1. When it’s closing, sometimes it gets into this repetitive cycle where the “hook” in the center tries to finish the motion over and over again without actually closing. I know it’s not done because the windows fail to roll up. And it’s also out of alignment I think as it sometimes scratches the aluminum anchor at the top of windshield (photo attached). This is leaving deep score marks and has me concerned.

2. when I close it, the fabric often falls outside of the channels on the frame of the top. I can see some cables running along the edge there. I’m assuming those have lost their tension and need to be adjusted or replaced? The top is in excellent shape so I’d like to keep it if i can. Anyone have a part number for those side cables? Are they easily replaced or can I just adjust their tension?

3. Today, as I was putting the top up for the night, mid close a rectangle-shaped piece of rubber fell down from the top onto the seat next to me. No idea where it came from, but if you can identify it and tell me where it belongs, I’d appreciate it. Hopefully it’s re-attachable or easily replaced. Possible part of my problem?

Not sure if it matters, But the previous owner gave me receipts showing the hydronic rams and the hydro mic pump we’re all replaced along with some cables a couple years ago. So the big components are newish.

Thanks in advance for your help and insights. This is probably one of many pleas for advice as I get this car sorted and running smoothly!



Hook and anchor point at top of windscreen. Notice the scrape marks in the center.

Mystery rubber piece

Another angle of rubber piece that fell as top was closing.

Top falls over the plastic channel on top

Different angle of mystery rubber piece.

pesuazo

I’m noticing three main issues:

1. When it’s closing, sometimes it gets into this repetitive cycle where the “hook” in the center tries to finish the motion over and over again without actually closing. I know it’s not done because the windows fail to roll up. And it’s also out of alignment I think as it sometimes scratches the aluminum anchor at the top of windshield (photo attached). This is leaving deep score marks and has me concerned.
This is related to the micro switch in the latch....i replaced the switch and added a bit of rubber, such that the hook pushes it all the way in...I usually "push" the hook with my finger as it closes to make sure the switch closes
2. when I close it, the fabric often falls outside of the channels on the frame of the top. I can see some cables running along the edge there. I’m assuming those have lost their tension and need to be adjusted or replaced? The top is in excellent shape so I’d like to keep it if i can. Anyone have a part number for those side cables? Are they easily replaced or can I just adjust their tension?
This issue is related to the strap that runs from one end to the other...it pulls the top "in" to make it fall in the channel...if strap is loose or "streched" it does not pull it in enough to fall in the channel
3. Today, as I was putting the top up for the night, mid close a rectangle-shaped piece of rubber fell down from the top onto the seat next to me. No idea where it came from, but if you can identify it and tell me where it belongs, I’d appreciate it. Hopefully it’s re-attachable or easily replaced. Possible part of my problem?
NO IDEA....It does not look like it belongs...
Not sure if it matters, But the previous owner gave me receipts showing the hydronic rams and the hydro mic pump we’re all replaced along with some cables a couple years ago. So the big components are newish.

Thanks in advance for your help and insights. This is probably one of many pleas for advice as I get this car sorted and running smoothly!

Different angle of mystery rubber piece

frisbee91

Two thoughts when reading your post.

1. Check that the plastic "hook cover" piece is in place
https://rennlist.com/forums/996-foru...p-concern.html
https://www.autohausaz.com/pn/158175...BoCW6YQAvD_BwE

2. Check the hydraulic fluid level
https://www.pelicanparts.com/techart..._Mechanism.htm

DetroitMatt

Well, the hook cover is indeed missing! I’ll replace that right away and see if that helps. At the very least it’ll help with the scratching of the finish by the metal hook. Hydrologic fluid is full and relatively clean looking. I checked that this morning and topped it off just to be safe, but it didn’t need any. It’s right up to the fill level hole.

Woodman71

Make sure you clip out about a quarter of the eyehole area on the hook cover, so you can slip it on easily. Also doesn't hurt to add a little glue in there.

I had my top replaced and it hasn't closed properly with full automation since. The hook starts trying to grab the latch area early. Now, I stop the top when it is about 8 inches above the window frame and pull it down by hand, then let the hook do it's thing when I am sure it is in the recess far.

Kind of a pain, but I am not prepared to drop big bucks just so the top closes perfectly on its own.

Good luck!

Mike Murphy

The only way to solve these Cab top issues [permanently] is to trade your Cab for a Coupe, lol.

I had the issue of the top side wires going over the outsides of the rails. I have since replaced the hydraulic rams, replaced a snapped guide arm hinge, and had a new top installed...and yet, every once in a while, the same thing happens.

DetroitMatt

Update: I have a plastic cover on the hook now. Once I glued it in and cycled the top a few times it works much better. It needed that extra mm of material to trigger the micro switch, so now no more endless loop of opening and closing. I’m going to call that one solved.

Upon further investigation though, I noticed that the plastic, square lever on the mechanism has broken off. Based on my research that is another micro switch that tells the mechanism when to lower the hook. Mine is snapped off and explains why the hook is still digging into the anchor point on the windshield. I’m also seeing a lot of glue and tape above that area where I believe the previous owner had attached this mystery rubber piece that fell off the other day. So couple more questions:

1. can someone check out the front lip of their cab top for me to see if this rubber piece is supposed to be there?

2. could this mystery rubber piece have been added by the previous owner to help compensate for the plastic lever being broken? If so maybe I should reattach?

3. what are my options for replacing the black plastic lever and making this work correctly? Is that a replaceable part or am I spending big bucks on an entirely new mechanism?

Thanks for your help everyone. I feel like I’m making some progress here.



Latch mechanism in its current state.

frisbee91

Not sure what modifications might have been done here.
Check this thread to see if it gives you some insight.
https://rennlist.com/forums/996-foru...h-plastic.html

sjg1138

"2. when I close it, the fabric often falls outside of the channels on the frame of the top. I can see some cables running along the edge there. I’m assuming those have lost their tension and need to be adjusted or replaced? The top is in excellent shape so I’d like to keep it if i can. Anyone have a part number for those side cables? Are they easily replaced or can I just adjust their tension?"

The issue of the side cables is most likely due to the rivets holding the cables (at the front) to the frame breaking off. You can replace these rivets. Check this out.
http://911uk.com/viewtopic.php?t=103442
In the link he uses a nut and bolt to fix it but rivet guns are cheap on Amazon.

JTT

If you put your roof into the service position (halfway up), and feel around under the roof covering, right in the area that is falling outside of the rail, you will find a little elastic strap that goes side to side (from door across to other door). I’m betting you will find the strap on one side, but not the other. Mine pulled it’s tab off one side prior to me having the car. Stitched it back on and roof falls into the rail perfectly now (and for last 5 years).