Ferrari Mailing List: 355 Spider Advice

[Charles Perry (charles]

The spider top has two problems, aside from just being an unnecessarily
complex design. There would've been nothing wrong with a simple manual
top like the Miatas have, and there have been threads on FChat about
converting the 355 to a simple manual top, although I haven't yet seen a
successful redesign.

The biggest problem is the seat position potentiometer, which is what
Clyde was referring to as the seat track. Attached to the seat track is
a little potentiometer which tells the top ECU where the seats are on
the track (all the way forward, all the way back, somewhere in the
middle). This potentiometer is attached to a cheap plastic gear and
clutch (to let it slip at full extension either direction). This little
plastic gear wears out or the clutch ball breaks off and then the top
won't go up or down anymore because the interlocks require that the seat
be in a particular position for the top to work (so that it clears the
tops of the seats when folding).

This happens often enough that I have rigged up a simple toggle switch
which I can plug in under the seat to force it forward or back when that
pot mechanism has failed. I have rebuilt a few of these seat sensors
from Jaguar parts (they have a very similar design and problem, but
their part used to be cheaper). Last I checked, Ricambi America was
selling the Ferrari sensor at about the same cost as the Jag, so it's
faster to just replace. It's a 30 minute job once the seat is out of the
car. If I had access to a good CAD/CAM system and a machine shop I could
build a similar part out of bronze or something that would last forever.

Second problem is fluid. The top hydraulic fluid seems to evaporate or
disappear in a place I never see it. I just know that at the beginning
of each season, I have to fill the hydraulic fluid and then run the top
up and down a few times to work the bubbles or whatever out. Never found
a leak. Getting to the top pump (between the seats) and filling is again
about a 30 minute job once you've got the trick tools worked out (in
this case a tiny funnel feeding a drinking straw or small rubber hose to
direct fluid into the tiny filling port on the pump).

There's also the problem with shrinkage of the boot for cars that see a
lot of sun or not a lot of leather conditioner, and the plastic window
eventually gets hazy, but that's most convertibles. I also find that the
top interlock to the e-brake is a PITA because at my height, the
steering wheel blocks the e-brake light and I often end up leaving the
e-brake engaged after raising or lowering the top because I can't see
the light.

-- charles



-----Original Message-----
From: cdatte [at] spawar.navy.mil [mailto:cdatte [at] spawar.navy.mil] 
Sent: Tuesday, July 29, 2008 2:29 PM
To: Charles Perry
Cc: The FerrariList
Subject: Re: [Ferrari] 355 Advice

I'm looking for one myself and would welcome your comments on the
spider.