Pinto Car Club of America

My oil light and dash lights were not working  on my 77 cruizer so I took the cluster out to do a general clean up of all the contacts etc, Then I noticed that the white plastic backing  piece on the cluster was basically crumbling in my hands. Very weird stuff. So now I need to buy a instrument cluster from somebody out there. Anybody have an extra lying around or a parts car with one, Thanks

I have one but the plastic is also starting to do that not bad at this point only one small hole.Make me an offer If you are interested.

Thanks for the offer. what do suppose is causing that plastic to decay like that  Smog?  Let me think about your offer, does it have all the dash light holes intack. My case broke around the light for the spedometer.  Thanks

All plastics are susceptible to degradation.  They will degrade when exposed to UV rays, radiation, heat and oxygen.  When a plastic is chosen for a particular job, the one with the right additives is chosen (or the additives are added as a concentrate which is melted with the pellets and homogenised in the molding process).  The additive will protect against what that plastic part will be subject to during its expected lifetime.  That expectation is around 15 years.  In the case of an instrument cluster, the degrading agent is heat (from the lightbulbs, and from the heater below) in the presence of oxygen (air contains 21% oxygen). 

Stabilizers are weak links within the plastic material that will take the hit from degrading agent.  At some point, they run out and are no longer able to take that hit.  That is when the plastic itself starts to degrade.  When this starts, it goes from bad to worse very quickly.  The part loses all of its properties and becomes brittle, breaking at very moderate stresses.

Make sure you get the right one.  There are two styles that I know of.  One with three idiot lights, and one with four.
--Doug