Preserving and Protecting your early Datsun Z

Owning a vintage car is not the same as owning a modern automobile. While modern cars still require maintenance, the maintenance intervals are often less frequent.  You can drive a modern car day in and day out without having  to do all that much and your car's onboard computer will often warn you of problems.

If you own a first generation Z (S30, 1970-1978) at this point your car is 40+ years old, with the earliest 240Zs rapidly approaching the 50-year mark.

The early Z benefits from regular use

Your Z's maintenance and care may not have been such a big issue back in 1972, because by 1972 standards the Z was fairly well engineered and built to be reliable. Daily use would benefit the Z and any problems that cropped up with mechanical components would be addressed as they happened.

Vintage cars are fighting two battles: first they are old, which means that many of the original components and systems may be old and subject to failure, for example, a 40-year old wiring harness. Second, vintage cars are typically driven very few miles and can sit for extended periods of time (including winter storage) and lack of use and storage causes multiple problems. These two battles exist regardless if your car is original or restored, as a restored car will begin to deteriorate over time, and restorations always vary in quality and extensiveness. 

At this point, if you have an early Z, you now have an investment that could be worth $15-50k and its a wise decision to protect your investment. Here are some things that you can do:

1. Look at the owners manual and the factory service recommendations and try to follow them. When your Z is no longer your primary vehicle, it is easy to over look simple maintenance items because the thought train is that "I'm not putting many miles on this car, so it doesn't need much attention." Many service items will specify mileage OR age, which means that you need to replace your antifreeze at 24,000 miles OR two years, which ever comes first.  It's not likely you will drive 24,000 miles, so pay more attention now to the time intervals.

2. Your Z has grease fittings- use them!  At the time you do an oil change, this is the time to inject grease into the grease fittings on the front end and rear axles. You should cover the front ball joints, tie rod ends and rack and pinion grease ports. At the rear of the car, the 4 universal joints. Note that for the U-joints, a needle type grease fitting will be much easier to use than the nipple type. If your tie rods don't have grease ports, you can still inject grease under the boot with a special needle injector.

3. Bleed your brakes and clutch, at least every 2 years. Brakes are a major system on the Z and you will have nothing but problems with your hydraulic system if you leave old brake fluid in for too long. Standard glycol brake fluid absorbs moisture and will eventually damage the master cylinder, calipers and wheel cylinders.  If your Z is driven very little and stored frequently consider using DOT5 silicone fluid, which is a better choice for show cars.

4. Upgrade your alternator and install headlight relays. The stock alternator on the Z was relatively low output (45A) and also used an external (technical) voltage regulator. You will notice on early Z's that the headlights may dim at idle and get brighter as rpm go up. You can actually run down the battery running the blower motor at full speed, with the headlamps on.  If you've added a newer car stereo that will draw more power, as will any halogen headlamps.  I can't promise this will happen to you, but at one point my very old voltage regulator stuck causing very high voltage surge which blew out almost every bulb on the car. This included both headlights, marker lamps, tail lights etc. The worst of this was the instrument lamps. If you've ever replaced the instrument lamps on a 240, you will know what I mean. Do yourself a favor, upgrade to a 60A alternator with an internal voltage regulator.  Adding headlight relays will also save your headlight switch and fuse box from damaging heat and current. These are relatively inexpensive upgrades that will protect your electrical system from future havoc.

5.  Fix little problems before they become big ones. That small oil or coolant leak won't get better on its own. If the car is losing coolant, you risk overheating and warping the cylinder head. Similarly make sure your sending units (temp. and oil pressure) are operating properly and remember to scan them when you're driving. 

6. Replace in pairs. For items that have a left and right, when one unit fails the other is not far behind.  If your LH front caliper goes bad, you should replace both the left and the right. Always do struts in pairs, although you don't need to do the front and rear at the same time, you can space these out over a year or two if you wish. 

7. Replace items at the end of their lifespan or before. If you know a certain component has a limited lifespan, for example a radiator hose, don't wait for it to fail. Just replace it by virtue of the fact that it is old. The same goes for fuel tank hoses, and any fuel hoses under the hood, which are subject to more heat.

8.  Replace or restore multiple systems together if it saves you time vs. doing them independently. For example, if you need to replace your header or exhaust manifold, that is a great time to rebuild your carbs.  Or if you need to rebuild the carbs, and your headers are old, it will be much more work to do them later.  When it comes time to do rear struts, that is a great time to also do the stub axle bearings, and rear control arm bushings.  By combining these jobs you will save time and money in the long run and have better reliability.

9. Refinish assemblies when they are out.  Because your Z has gone up so much in value, and isn't being driven that much, it's a great idea to refinish components (either by power coating, or using POR) on suspension components, subframe assemblies etc.  This is more work, time and money but you will be preserving your car for years to come by refinishing these components. 

10. Get your Z up on a lift. This should be done regularly, at least annually to inspect all systems from under the car- exhaust, engine, trans. , differential carrier, brakes etc. You will see hidden problems before they leave you on the side of the road.

11. Drive your car! Your car will go bad from sitting too much. Fuel turns to varnish. Seals dry out. My '71 was barely driven 1,000 miles in 10 years. Here is what went bad: distributor (lack of regular oiling caused worn shaft bushings), brakes (wheel cylinders, calipers, master cylinder), fuel hoses (dry rot), carbs (gummed up), water pump failed (gasket dried out), oil pan leak.  Tires can also develop flat spots and will go bad just from age.  Try to drive your Z 2,000-5,000 miles a year. I realize that mileage can affect value, but if you let your car sit, you've spent money on something that you don't use, and it's systems will deteriorate further reducing your value!

12. Keep a maintenance journal. Keeping a record of what you have replaced or serviced will help you remember what to do in the future. You should also make notes of known problems that you plan to fix later on, so that you don't forget about them.

My First Concours D'Elegance

A Mercedes 190SL during Saturday's event


It was supposed to be a Datsun weekend. The plan was to drive the 240Z to Saratoga Springs early Saturday for the Hemmings Import & Exotic show.  But a host of mechanical problems including a sticking throttle and wandering steering kept me working on the Datsun through Friday. The final test drive on Friday was revealing; there was still a significant amount of exhaust fumes coming in the cabin, with the windows down. The thought of driving 3+ hours (each way) with fumes coming in the car was not enticing. I might be able to make it there with the windows up (no fumes) and the blower fan, but certainly not on the drive home at 2 pm, with temperatures in the 80s.

The decision was easy then, rather than 6 hours in the Datsun, I would take the SLK to a local Mercedes show in Northeastern CT, which was only a 1 hour drive each direction.  Because it was already past the deadline to enter the Concours as a judged vehicle, I was told I could enter "display class" which allows you to show your car on the same field, without judging and pay only $20, instead of the $85 for the judged competition.  The SLK needed no preparation other than vacuuming and a quick wash and detail.

I set out on Saturday morning with the top down, but it only took a few miles on Route 90, which was busy with summer traffic, including large trucks, to realize that the top needed to go up. I pulled off into Charlton Rest area, pushed a button and 22 seconds later I was driving an air conditioned coupe. Once getting off Rt 90 to 395 South, the traffic lightened and the drive was a bit more relaxing. After exiting the freeway for good, I dropped the top again and drove the final 9 miles on quiet country roads in a rural part of Eastern CT.

I'd only seen coverage of prestigious Concours events on TV or in magazines... Pebble beach, Amelia Island.  To show a car at those events you have to be invited, and only the most significant, rare cars enter.  Even to be a spectator at those shows will cost you at least $100.  All the car shows I'd entered to this point were "people's choice" meaning that there was no real judging and cars won based on votes from the attendees who voted by ballot.   At a typical Datsun show I'd seen a lot of modified cars, which run the gamut of typical mild performance upgrades all the way to radical V8 conversions. As of late though, I have seen more original or close to original cars at the shows.

Doing a factory correct restoration is a different endeavor, it requires time, research, learning and of course finding the correct parts (either reproduction or refurbished original). A few years ago there was a tendency to over-restore (i.e. better than new) but that is mostly gone now, as the judges are looking for cars as close to factory original as possible.  The best, and most valuable Concours quality cars are trailered to the shows and the hobby becomes more focused on events (i.e. shows) than on driving.

The Mercedes SL dates back to the 1950s, the first real SL being the 300SL gullwing. Less than 2,000 of these cars were produced, and it was followed by a roadster version that had standard doors.  When the powerful, racing oriented 300SL was retired, what followed was a much less powerful 190SL, which shared the body style.  With 190SL values already above $100k, restorers turned their attention to the 230, 250 and 280SL models, which used a fuel injected inline 6-cylinder engine. The 280SL is really more of a touring car than a sports car. It does have very clean lines and these models
A 280SL with "Pagoda" style  hardtop

are now also crossing the 100k mark.  I was told by one of the restorers, that the cost to restore an early 70s SL was over $100k.

The 380SL and newer 560SL are also crossing into collectability now. These cars were very expensive when new, and they are even more expensive now, for a good low mileage example or high quality restoration.


A restored engine bay on a 380SL V8 model.

Mercedes supports its hobbyists very well, and most factory parts for these old cars are still available- don't ask about the cost!  When you see the cars in  person  you realize the amount of time and effort needed to achieve these results.

So, the event was not "snooty" at all, despite what seemed like an army of white-shirted judges who descended on the cars like a swarm of bees, each with a clipboard taking notes of the interior, paint, trim and engine compartment. The scoring was done at the show, but the awards were not until the evening and I was long gone by then.

For the drive home, I checked the "avoid highways" on google maps, which increased the drive time from 60 min. to 80 min. but I was treated to some nice rural backroads in CT and MA rather than the monotonous view from the interstates.  On most of the back roads, the speed was 40-60 mph, but that made for a nice leisurely cruise home with the top down.