I've never had a problem with my cluster (by which I mean the black plastic housing the holds the speedo and heater controls and so on) warping, but it seems like a big deal in the US.
I've also heard that they changed something by adding a steel reinforcement, but that caused a crack instead of a bend, or something like that.
I'm curious for trivia reasons, but I'd also like to understand the issues before installing my NOS one in my 2+2. Not that it'll see a ton of heat, but it is a convertible and what driving it does do will likely be top down!
I don't know, Dave, but I suspect it may be an environmental thing. The southern U.S., or sunny California can really sun load things like dash pads. Up hear in the Great White North it took a long time before a/c was offered, let alone considered by many. We generally don't get the intense heat & sun loading that others to the south get.
One dash that was always very susceptible to cracking were the 1971 - 76 Chevrolet Big car dashes. The one on dad's '74 cracked within 2 years and when I started looking around, I was hard pressed to find any without cracks. The dealer replaced the dash in 1976 and that one never cracked. They must have made an unseen change on the final 76 versions.
__________________
67 Chevelle Malibu Sport Coupe, Oshawa-built 250 PG never disturbed.
In garage, 296 cid inline six & TH350...
Cam, Toronto.
I don't judge a man by how far he's fallen, but by how far back he bounces - Patton
There is a very good chance that in 69, some injection moulded interior parts on Canadian cars, might actually have been made in Canada.
Such a theory could account for the difference. I know for a fact, when I pulled my 69 apart, down to pretty much every nut and bolt, I'd been surprised to see "Made in Canada" on quite a few pieces.
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
Indeed certain stuff is sourced in Canada, though I don't know how much they had to. Like frames came from BUDD in Canada, I've learned, and are a little different in the US.
My steering wheel has the same part number but is a different casting/mold than the US NOS piece I have. Stuff like that.
I swear I saw "Made in Canada" stamped on a dash pad back, nose piece and moulded into that black dash bezel somewhere. I believe the door panels were made by Allen Industries Canada, and the AM radio was made here.
The interior temps between the north and south for sure could account for the damage. As we know, it gets hot up here, perhaps sometimes even as hot as the south on certain days, but obviously the duration of such is far shorter.
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
The 1969 & 1970 cluster surrounds are basically the same. A big difference is the wiper switch and how it mounts, and obviously the imitation stainless trim on a 69 vs fake woodgrain on a 70.
I'm not sure if I have a 69 cluster surround downstairs to compare, but I know the 70 cluster surrounds have the metal reinforcement across the top you speak of above.
This is my 50 year old unit (after restoration, so the cluster is likely not the original to the car though) that has seen a fair bit of sun - enough to crack a blue dash, but not warp or crack the cluster.
There'y not perfect as you can see, and I imagine MCR tried pretty hard!