Cabrio top transmission gearing and Top latches
09-25-2010, 02:58 PM
#1
Cabrio top transmission gearing and Top latches
I stupidly managed to break my 1997 cab’s top gear assembly on the driver side behind the seat, necessitating purchase of a used transmission mechanism. This is the circular gear device with a transmission on the side that takes a cable from the top motor, which in turn is located in the rear center of the interior. The transmission part number in the Porsche schematic is 993.561.045.00 70B *3, but the part in my car that broke ends in 045.03.
The part German Auto Dismantlers sent me (now installed in the car) had a slightly different part number on the case and had a cable with an end piece that was slightly different and had to be replaced with the cable from my broken transmission, which was fine. The top mechanism then worked fine physically, with both sides going up at the same pace and time.
However, the front top latches (that rotate to clamp down on the windshield frame) then failed to do so and have to be rotated by a screwdriver. A clicking sound from the dash area implied a control unit or relay issue had arisen. This seems highly coincidental that the control unit or the sensors for those latches (which are on the Passenger side transmission unit, not the one that was replaced) would have gone at JUST this time. But the dealer (where I finally brought the car) does not think the cause is other than electrical- the control unit, the micro sensors or wiring in the top itself. However, the dealer says Porsche upgraded the transmission during the 993 series and my 1997 car had/has the newer ones. He cautioned that over time the differences in gearing might cause a strain and result ion top problems.
My questions: 1. Should I worry about the “different gearing” in the two sides of the car over time and should I insist German Auto send me the later transmission type for my 1997 car? 2. Could the gear difference somehow be affecting the top latches? The latches are actuated by two micro-sensors on the passenger side only and the driver side unit has no effect on these micro-sensors or the control unit the dealer says he needs now to check.
The part German Auto Dismantlers sent me (now installed in the car) had a slightly different part number on the case and had a cable with an end piece that was slightly different and had to be replaced with the cable from my broken transmission, which was fine. The top mechanism then worked fine physically, with both sides going up at the same pace and time.
However, the front top latches (that rotate to clamp down on the windshield frame) then failed to do so and have to be rotated by a screwdriver. A clicking sound from the dash area implied a control unit or relay issue had arisen. This seems highly coincidental that the control unit or the sensors for those latches (which are on the Passenger side transmission unit, not the one that was replaced) would have gone at JUST this time. But the dealer (where I finally brought the car) does not think the cause is other than electrical- the control unit, the micro sensors or wiring in the top itself. However, the dealer says Porsche upgraded the transmission during the 993 series and my 1997 car had/has the newer ones. He cautioned that over time the differences in gearing might cause a strain and result ion top problems.
My questions: 1. Should I worry about the “different gearing” in the two sides of the car over time and should I insist German Auto send me the later transmission type for my 1997 car? 2. Could the gear difference somehow be affecting the top latches? The latches are actuated by two micro-sensors on the passenger side only and the driver side unit has no effect on these micro-sensors or the control unit the dealer says he needs now to check.
09-26-2010, 05:37 AM
#2
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my experience is very short so take this words with prudence
I see you don't speak about the front switches, these affect the latches working during opening (infact when the top goes up reaches the switch on the passinger side and makes the latches to work)
I think, but I'm not 100% sure, that the difference between earlier and last gearing is only into the coupling (the cable ends with the gear, instead of being in two pieces)- so you can't worry about this
If the main gear is identical it doesn't affect the top latches
p.s. I have the passinger side gear frayed/eated, it still works but is not perfect; if you don't use this part, please let me know - should be fine for me
I see you don't speak about the front switches, these affect the latches working during opening (infact when the top goes up reaches the switch on the passinger side and makes the latches to work)
I think, but I'm not 100% sure, that the difference between earlier and last gearing is only into the coupling (the cable ends with the gear, instead of being in two pieces)- so you can't worry about this
If the main gear is identical it doesn't affect the top latches
p.s. I have the passinger side gear frayed/eated, it still works but is not perfect; if you don't use this part, please let me know - should be fine for me
09-26-2010, 11:02 AM
#3
My thought also was to check the micro switches on the passenger side, since thay close to zend the signal to the top latches. The Porsche tech checked them, he said. (On reflection this weekend I did not see him check them electronically, but rather he said he pressed them with his hand to close the circuits. I will be sure to ask him this week if he checked tham electronically!) I had hoped it was these switches. By the way, my passenger side transmission unit is excellent and I would not be disposing of it. Sorry, and good luck getting one. I would try DCAutomotive (after they get them back in stock) since they are more reliable then German auto dismantlers based on this experience. Also cheaper.
