Hi-Step'n370Z,
From years of working on all kinds of cars, many of them convertibles, I personally think that little use of the top mechanism, and a lot of use, are the cause of many top opening/closing problems.
In the little use department, hydraulic rams tend to stick in their parked location over time and resist moving when next activated. Ram hydraulic seals tend to harden over time, then eventually leak, particularly when the top is stored over lengthy periods. Electrical wiring for the various sail switches on the rams tend to take a set (like the wrinkles in the top cloth) when stored for lengthy periods, and then break/crack as the wiring ages with the years and hot /cold climate changes. The ram rods , with lack of use, tend to develop surface rust in humid climates and score the seals leading to hydraulic leaks.
In the frequently used department, the wiring frays and breaks from the constant flexing at the fold joints of the top. The rams eventually wear their seals resulting in leaks, and the bungee cords lose their elasticity and don't pull the various top bows out of the way while folding. Hinge joints wear, develop slop and tend to jam, stressing materials, wiring and the top motor and pump.
The tops of 370z's are very intricate, unlike the top mechanisms of convertibles from the 1930's up to the 1980's. Those older cars were either opened and closed by hand, or one hydraulic pump and ram opened and closed the entire top. A failure of those systems were easy to track down and repair. Not so, the top systems of our chosen ride.
I believe that those who use the top mechanism a lot (and I mean a LOT) and those who use it very little (two or three times a year) will have the most top issues.
The best scenario for not having a top issue is to lease this roadster new, and trade for another one before the warranty times out.
For those of us who are into the Roadster for the long haul (my last Z I traded for this present one after 27 years of ownership), I suggest that cycling the top, say once every two weeks at least, is the way to go to prevent the issues of lack of use, for those who seldom put the top up.
For those who have the top up and down frequently I suggest setting aside some money every month towards future repairs, and for those who are mechanically inclined, getting the factory service manual, and educating yourself in the top mechanicals, as many minor issues can be traced down and corrected in your home garage if you understand the system (Bungee cords, frayed/broken wires/leaking hydraulics/etc).
Personally, the only top issue I've had is the 5th bow bungee cord not doing its job, but with some readjusting the bungee, and some helping of the movement of the 5th bow by hand(while outside the car, using the door unlock switch button to lower the top) the problem seldom appears with any regularity.
Gene
|