I don't know about all of them, but several zx's I looked at also had broken speedo's, including the one I bought. It also could be the cable needs lubrication, but my experience has been the speedo.
You can replace it with a 130mph, or another 85 mph unit fairly easily. The gage cluster comes out if you drop the steering column and have small hands to unplug everything. The cluster comes apart easy by removing a few screws. If you have the check computer, it is a bit tricky to get that back in just right, but fairly easy.
Joe at All Z East should be able to help you in getting the speedo, just let him know if you have cruise control or not. They seem to have the best prices and supply that I have found. Send him an email at [email protected]. You can call his 800#. Look for it in other posts here at zcar.com. I don't have it handy.
> I just got a 1980 280zx on the 17th and i
> have been looking around. Do all the
> speedometers get peged at 85 and break? Mine
> is broke and alot i have looked at are also.
Before you junk the speedo call my company, Russack Dri-Slide, toll-free at 1-800-231-6901, and place an order for a 4 oz. bottle of Dri-Slide Multi-Purpose with a needle. The price is $7.95 plus $3.95 shipping & handling and we take Visa and Mastercard. This is a moly lubricant that you put into the top of the cable and let gravity carry it down through the cable. It very often solves the problem by simply applying a dry lubricant (it goes on wet and then dries so that it doesn't attract dirt and dust) completely throughout the cable. It can also be used on ALL places in your car where you've got metal-to-metal contact and will quiet squeeks. And trust me when I tell you that we don't make our living selling individual units, we do it as an accomodation. One of our largest customers is the New York Subway system who buy it by the pallet-load and use it to lubricate the sliding doors on 7000 subway cars!
give it a try.