ghiaben

Hi all,
Just coming up on 1 year of owning my 90 C4 cab and it was time to attack my first major fix, my cabrio top. I have been reading and reading and researching Rennlist, sucking up all the information, and finally I decided to take action.

I had 2 problems. I was under the impression that only one side operated the top and it seemed that the motor was working a bit harder than it should. Also, I had an intermittent problem with the top latch which sometimes would only go halfway then stopped. It would take a lot of back and forth, flickering the switch to get it to close...whenever it decided to...

First I unclipped the cables from the motors to see if they were shortened like I was in one of the DIY. They looked good so I checked the transmissions and what do I find? Aha! It's kind of loose. On the driver's side's transmission, one of the mounts is broken!



But that's not all, the mount just above has no nut to thread into...so the whole thing was hanging by only 1 out of 3 bolts...of course it was only operating on 1 side!

Here's what I decided to do: Weld a nut to a washer and weld the assembly to the car. Here on display my VERY POOR welding skills




I basically made the whole bigger (yikes I'm drilling a big hole in a Porsche!!) and inserted the nut-washer assembly nut first. I then tack welded it to the car. It was a pain in the neck to protect the car from sparks flying from the MIG welding. I know it's not pretty but it works! I put a little paint to cover the naked metal and voilà! A new nut for my bolt to thread into!

Then I was trying to find a solution to the broken piece. The transmission is made of aluminium so I was not equipped to weld to it. After some research, I decided to try a product called Cold Weld from Permatex. It's basically good old epoxy but says it's formulated for metal. I sandwiched 2 washers and a custom made spacer and here is the result:





I'm very happy with the result. Everything is very strong and tight.

I also took both transmissions apart to inspect and grease everything. I followed a procedure to align the transmission arms that I found on the Pelican boards. http://forums.pelicanparts.com/porsc...sm-repair.html



Now onto the top latches. I found a few threads in the 993 forums that talked about cold solders in the top control module.

https://rennlist.com/forums/993-foru...er+top+control

After reading it I was so convinced that I ran to the store to buy a soldering iron...(couldn't find my old one...) and a magnifier. Yes, it was a royal pain to get to the box, but I was excited! Did all the solders put the whole thing back together and bingo! It works!!!

Before putting it all back, I decided to do the 3rd fix, which isn't really a fix but I really wanted to be able to operate my top while the car was running so I did the mod. Link I found for this mod: http://lightning.prohosting.com/~dat...op_control.htm

Yes the top light stays on but I really need this functionality since I drive this thing with the top down as much as I can, even with gray clouds!

So there you go! Porsche newbie very happy and proud! Thanks so much to all for the wealth of information provided here. I spend so much time studying it, it was about time I executed!

Later!

DDotson

Congratulations on the great results, good to see a success story!

Amroth

I have always been able to operate my top with the engine running (90 c4 cab). Does that mean the PO had done the mod already?

jimq

I can operate mine while moving slowly. Great post

hawk911

huh.. not even an option for me. The car has to be off to operate the top. nice post.

ghiaben

Amroth, he probably had the mod done. Unless european models are different?

I also posted the wrong link for the top control module fix. Here's the right one:

https://rennlist.com/forums/993-foru...er+top+control

franc.rosendal

Great post, thanks. My top wasn't operating, although both motors were working. Turned out that the inner cables were not connected anymore, so I had to shorten the outer cables by cutting out a small piece and reconnecting them with a hose over it, which I glued to keep it in position. The inner cable is now 10mm outside the outer cable and the drive wheel is now properly working. I'm currently assembling everything and wondered what grease did you use for the cables and the drive unit?
Thanks for your reply.