The most unreliable part of a Z (Well nearly)

For the purposes of this article we are going to focus on the interior of the Z.

I have espoused many a word on the engineering integrity of the S30 series, using the potential boring term of reliability as an asset to this, boring on paper maybe, but in reality it just means you enjoy the driving aspect of the car every time and the ‘working on’ aspect whenever you want to, not when you have to.

It has to be said that since the rebuild of MBP (thank you once again Richard) I have merely serviced the car, and whilst it has been proven that it doesn’t drive as well as a Z should, Pete Forders ‘2 JOU’ has proved how good a Z can be.
But the Z is not perfect, we know that the interior was trimmed down to a price, with copious use of plastic, but nonetheless it is a lovely place to be and the dashboard is a joy to behold.
The dashboard is actually the focus of my claim for un-reliability. It is actually the most iconic part of the dashboard that offends.

The three central gauges have been carried through (almost intact) to the latest Z34, therefore it seems strange that it is the focus of my criticism.

But most Zs have a guage in the cluster of three that is has either never worked or has stopped working.

The clock can always claim that it is correct at least twice a day (Mine is a case in point).

I speak to so many people and they voice the same criticism of a gauge that was probably the easiest to ‘get right’. In fact it is a surprise when I step inside a car with a fully working clock.

Later vehicles addressed this shortcoming and I remember my Z31 and the Z33 having a perfectly working time piece, so what was the problem?

Many have removed the clock and flushed it out with WD-40 and then lightly oiled all the components.

The clock appears to work for several months and then stops again

When you look at the clock in detail you can see why. The automotive environment is very tough on all the components and the most critical parts are hermetically sealed.

The first generation 240Z Datsun clocks were not hermetically sealed and susceptible to all the dust, dirt, chemicals, humidity and temperature.

JECO, the Datsun subcontractor, who built most of the Datsun clocks never used oiled for good reason. Oil attracts all the nasty contaminants that can wear out critical clock components and eventually grinds the clock to a halt.

We know everyone always uses oil on their grandfathers clocks. If you think about it we change our engine oil which is filtered for the very same reason, so that the engine will last longer and not wear due to….the dirty oil.

The first generation clocks have what’s called a “NO LOAD” motor which keeps the main spring of this clock contiguously wound.

The rest of the clock consists of gears, paws, and bearings that rotate and work in unison to move the clock hands.

The problem is that any gear or bearing that produces friction slows the entire clock and if severe enough the clock will stop.

Are you beginning to see a pattern here?

Oil that is used to lubricate (all oil) coats the surface of moving parts and eventually starts to collect crap.
Eventually this causes the viscosity (on a micro level) to thicken and produce resistance to the overall clock operation. In addition the change in temperature alone will change the oil viscosity.

It takes very very little resistance in any of the clock parts to stop this mechanism.

When solvent other than alcohol is used to “flush” the clock all your doing is removing the contaminants, but when you apply oil you start the process all over again.

If you don’t mind removing your 240z clock every year or so then I guess that’s ok.

What appears to work the best is denatured alcohol.

You should remove each and every clock part, clean all parts with an artists brush, inspect the cleaned parts, and reassemble (NO OIL).

This can be a rather daunting task and is not for the weak of heart or those with limited patience.

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