GRUWEZ

My 964 Cabriolet has the following problem with the convertible top. When I start opening it, I notice the right hand side comes up earlier then the left hand side. This results in a slight binding of the LH side guide pin in the hole of the windshield header. Just some slight rubbing, but still annoying. The main problems is when I raise the top again. Once the top is halfway, the front part just falls down with a big bang onto the windshield header. So I have to hold it with my hand and lower it gently onto the header.

Any idea what could be wrong?

tfitch03

I am so scared to break my top I raise and lower manual and use the switch to lock and unlock.

Maybe your left hand cable that attaches the motor to the mechanism has stretched and it isn't 100% aligned with the right anymore due to the slack.

Freya

I speak from a bad experience, many years ago. The first time I attempted to lower the top on our '91, one of the support arms broke. The problem was that one of the cables was not working. I had the arm repaired by a good aluminum welder and replaced both of the cables. The top's mechanical mechanism has been the subject of many posts, and I usually put the top down in the spring and don't put it back up until the late fall. But then, the car is located in the California Central Valley, where it never rains during these months.

Harry Apps

GRUWEZ, if the top does not move equally, don't use the motors to open/close! You will likely put too much strain on the Bow (B-Pillars) and one will break - that will cost a fortune. Don't ask me how I know, I am just finishing off changing one. Hood alignment details are available here, don't worry about the year, it make no difference:

http://www.pcarworkshop.com/index.ph...C_Parts_Guides

If the hood drops under its own weight, this implies that the quadrant gears are becoming unmeshed.

JJJMCD

I had the same issues with my top. Once it eventually broke one the main top arms (I had it welded), I converted the top to full manual by loosening the rear motor bolts and getting the DC Auto kit with the manual windshield header panel L-handles. Stress-free convertible top operation!

GRUWEZ

Thanks to all for the tips/advice. I will remove the trim panels and have a look at the quadrant gears, as Harry suggested.

Freya

Hey JJJMCD. Would you please explain just how you modified the latches to a manual mode?

Jerry G

GRUWEZ

OK, here is some follow up. Motors, cables, microswitches and gears are all fine. The problem lies with both transmissions. The actuator lever, which connects the transmission to the top mechanism, is held in place with a slot/notch onto the big transmission gear. Apparently over the years, the bolt holding the lever in place came loose and caused a lot of wear on both slots and notches. As a result, there is a lot of play between the lever and the transmission.

So... I am looking to buy a set of good used transmissions, complete with the actuating lever. Anyone out there who can help?

Thanks!

Freya

GRUWEZ

I was just working on my top for my '91. I finally just loosened the bolts to free the levers. I then popped the wires from the "trip switches" next to the two front latching motors and "hot wired" the motors with a short piece of wire to simulate the actuator switches being always engaged. I did this because the top edge was not meeting the windshield frame enough to trip the switches to actuate the motors. I now can open the top by engaging the cabriolet top switch on the dash to open the hold down cam levers. When this is accomplished I can easily manually open the top. Closing is the reverse of above. I simply got tired of all the adjusting of the motors and buying new cables and fearing breaking the top arms, once again. Plus opening and closing the top is faster. Another plus, the cost for this fix is "zero."

Harry Apps

Freya's option is one solution that is based around the "emergency" procedure given in the handbook. Many Cab owners just use that system, without altering the wiring, to operate the hood - leave the transmission bolts loose (4 turns), open/close hood by hand (speedy) and lock/unlock using the switch. This will avoid the nightmare and expense of breakages. Transmissions are the same for 964/993 and Ebay.de can be your friend. There were a pair on on last week (sorry) I think from the same person that has the locking motors listed.

GRUWEZ

I bought a set of refurbished transmissions on eBay Germany. Keeping my fingers crossed that they are good.

Robbrizzle

Like tfitch03 I was nervous about closing the hood on mine for ages as it would whack the top of the screen with some force unless guided in gently by hand.
I finally sorted the issue by adjusting the microswitch on the leading edge of the arm so that it would stop earlier in its anti-clockwise rotation, stoping above the screen the letting the locking motors engage and pull it down into its final closed position.
On mine the roof open microswitch appeared to not respond thus it would keep opening until you stopped pressing the switch. This turned out to be a fault in the cab roof ECU, which despite attempts to re-solder was only resolved when I replaced the ECU. The replacement from Porsche having the added pin meaning it had to be wired into the handbrake as it was designed to only function with the handbrake on.
As far as keeping the arms on the gearboxes in sync, I disconnected the ends of the arms from the frame end, rather than at the centre and then disconnected one of the drive cables at the motor end (behind the rear seats) then used the switch to move the arm which was still attached until they were both back in sync.
Roof has worked great for some while now, only problem now is the cab roof light sometimes stays on when the roof is closed.
Also, somewhere along the line I replaced one of my locking motors as the spindle in it had snapped. Now when I close the roof one of the locking motors is silent when it's closed and the other one keeps clicking, not sure if this was a later design of whether one of them is spannered and thus explains the cab roof light not going out when the roof is closed?

g60pops

Robbrizzle is your car a strosek? If yes, any more pics?

Robbrizzle

It is, but also in need of a bath and minor cosmetic surgery.
As I use it everyday, I've been focusing on the mechanics rather than the aesthetics.
I have however tried to upload some pics but keep getting parse errors, sorry.

JJJMCD

Freya, it is a kit sold by DC Automotive, which replaces the motors in the windshield header panel of the convertible top with the manual L-handles from a 3.2 Carrera targa. The "rollers" actuated by the motors are a little differently shaped than the rollers for the targa L-handles, so the inserts in the windshield header panel are replaced with ones from the kit.