Bituman

Last Saturday I tried to put the top down. The locks that attach the top to the windshield frame disengaged properly and the top went back a foot or so and stopped. There was no loud noise, it just stopped. When I pressed the switch to raise the top back to the windshield frame, the motors ran but the top didn't move. Eventually, I loosened the 19 mm hex bolts and the top is now operational in manual mode. The locks still engage and disengage properly.

I have not had a chance to try to diagnose the problem, but I need your opinions regarding operation of the top. On one hand I would like for the top to lower and raise automatically, as designed. If this is a simple bound mechanism that I can fix myself, I will just do that. But on the other hand, I have heard that fixing a broken cab top mechanism is pretty expensive and worse, can be a reoccuring problem. Based on comments on this forum, the cab top mechanism does not seem to be one of Porsche's better engineered features. Thus, some on this forum seem to favor leaving the top manual. What is your opinion? Anybody with any experience with this? Thanks.

Bob

Danz C4

On the contrary, I think the top mechanism is an outstanding example of Porsche engineering. My top has worked fine for over two years. Of course that is after a day spent adjusting ALL of the limit switches and variable length tension rods and cables to factory workbook specs. To me, no different than enough oil in the engine, or correct air pressure in the tires. Get it right and it works.

Far from a simple mechanism, but you can fix it yourself.

Danz C4

Bituman

Well I really need to get in there and figure out what happened. So I appreciate your advice that I may be able to fix it myself. Actually, the comment on the mechanism not being one of Porsche's better engineered features came from none other than Adrian Streather in a post back in 2003. Actually he was applying that comment specifically to the top transmission. His words:

"Transmission jam on one side. Not an uncommon failure especially if no preventitive maintenance has been carried out. The transmission is a very non Porsche type system. Poorly engineered. Needs lubrication and checking. However there is normally indications of an impending failure."

Anyway, I'll check things out this weekend and hopefully figure it out. Thanks again for your thoughts.

Bob

Gus

Bob - I am in the process of repairing and replacing the cab top on my car - What I have found so far may be of some help - I think that you probably lost the drive to the main gear on each side - I suspect that you lost one earlier but the top stilled worked - There is a small box that holds the worm gear drive to the main transmission (gear case) for each side of the top ( These are easy to get to and see once you remove the side panel (interior cover) on the left and right side of the rear seats) Look and see if the smaller gear box is firmly attached to the larger black gear box. Both of mine had the screws holding them in place backed out and were very loose - This allowed the worm gear drives from the motors to just spin and not drive the main gear inside the black housing. After I repaired these and fit back in place I noticed that one side was not being driven by the worm gear - ( driven via a cable from the motors ) The motors are located in the middle of the rear large carpeted area just above the back of the seats when folded down - here there a few screws that hold the carpet in place, undo and lift up the carpet. Yo will then see a large sheet of padding. Mine was glued down. I felt the motor locations in the middle ( there are 2) extend about 8 inch each side from the middle. I then cut a line on the left and on the right that would allow me to lift the padding with out tearing it up . There are motors for the left and the right side drive. Each hasa cable going to the drive transmission. For some reason over time the cables seem to get shorter and don't make contact inside the drive cog of the motor. To repair, pull the clip that is on each end of the motor and check the length of the cable sticking out. The both should be about the same - If one is shorter - you can replace the cable or ( do as I did ) and cut back the tip of the outer housing on the end of the cable that goes into the motor. I cut min back about 3 / 16 inch and the drive works fine. ( I used a small Dremel tool with a fiber cutting wheel) Oh! pull the cable out via the worm gear side so it is no in the way when you cut and don't want to damage. You will see all this once you get into the area. These repairs are very easy, but adjusting the roof is not - it takes a little time to get everything lined back up as each of the drive arms ( held in place with the 19 mm hex bolt) have to be readjusted to be in the same position. I did this by hand - What I did was dis- connect the top from the arm off the black gear box (19mm bolt arm) on bolt at the to of the 19mm arm . Then I could turn the cable by hand and get the 19 mm bolt arm in the same position. Once I did this I bolted back together and checked operation -I did this several times - but it is smooth now. I hope that this helps a little -

Bituman

I am going to tackle the top over the weekend and your post will help me a lot. I especially appreciate your comments on adjusting the roof. I have heard that can be tricky. Many, many thanks.

Bob

Gus

Bob - Hope all went well over the weekend - I decided to take a break from my top and played golf all wekend - What did you find out? - hope it was not any major problems _