Interesting, though I don't understand the purpose of the opaque film. The tube is larger than I assumed. It doesn't slip over the bulb but is somehow affixed to the cover.

The speedometer has been removed and repaired in the past as it was seized up. The tube may have been lost at that time though I wasn't the one that did the work so can't say.

On my '55 400, the red high beam indicator at the top of the speedometer is lit whenever the instrument lights are on. Toggling between high and low beam just increases and decreases the instrument cluster illumination.

I'm guessing there's supposed to be some sort of paper tube snugly surrounding the high beam lamp, which is missing. Am I correct? If so, any tips on how to fashion one the correct diameter and length to fit into the instrument cluster?

The point seems to be getting lost. The date of the study is irrelevant. It's the data that's informative and it is what it is. I was sharing it to provide some relevant context, although it happened to be mostly focused on fatality cases as that information is what was available for comparison. Injury statistics weren't available then.

The issue is that with the four door vs. two door you have a quite stout seat frame. Slam on the brakes and a rear seat passenger isn't going to be slamming you into the steering wheel or dashboard as they hit or simply brace themselves against the seat back.

As a driver I don't want my face planted into something by a rear seat passenger, or even be hesitant to hit the brakes for fear of it should a kids ball roll out in front of me, etc. I've already stated my intent to install period correct lap belts to mostly remedy that. Even with them the rear seat passengers can still react by shoving on the seat back with their hands as they are thrown forward, but the likelihood and severity is reduced.

However, more obvious is simply the seat back flopping forward under hard deceleration which I would think would have been apparent to the Packard test drivers and engineers which a simple latch would remedy. Packard engineers weren't prone to overlooking the obvious.

None of this is simply "driving with common sense". It's just driving, which involves conditions and actions not entirely under the driver's control.

BTW, my '55 Patrician came equipped with a single lap belt for the driver only (and leather upholstery). It seems just about any combination could be ordered by the customer, with the exception of a seat latch.

Quote:

Well, seat belts were not required to be standard equipment in the US until 1968, and the first state to actually require their use was New York the end of 1984, so the lack of a law doesn't necessarily mean it was safe, but I agree it does imply a lack of concern.

However, the 1968 seat belt mandate included a mandate for seat back locks in two doors. A 1987 crash safety study (ref. DOT HS 807 067) was published comparing two door to equivalent four door models, specifically focusing on the seat back latch as a factor in injury/fatality statistics.

The findings were that in even moderate head-on collisions ~26mph with unrestrained adult rear seat passengers, the seat back latches in two doors were inadequate and in most cases would tear loose from the seat frame, so did not provide the perceived safety. Unrestrained adult rear seat passengers often ended up in the front at even lower speed impacts.
There appeared to be a benefit when the rear seat passengers were children who with their reduced mass were more likely to be contained within the rear compartment and not hurled into the windshield, or with adults in low speed frontal impacts ~10mph.

A totally separate question but still related to seat backs, how does one remove the seat back cushions? Does one remove the bottom to reveal fasteners below the back cushions? This car still has the plastic seat covers on just the front backs and they are a bit ratty with the corners and some seams split out, so was wondering what it took to remove those covers.

In my recently acquired '55 400 the front seat backs apparently have no latch mechanism. They are free to fall forward with heavy braking or by a rear seat passenger. Is that normal on these cars? It's not at all safe.

My intention is to install period-style lap belts but the seat backs remain a safety issue.

Interesting information. It sounds as though the '56 junior fenders, which don't have the brow over the headlight, nevertheless aren't interchangeable with the '55 Seniors due to the slight crease along the top which was omitted in '56.

What front fenders, irrespective of trim differences, are interchangeable with the '55 400? I assume all '55 seniors are the same but what about the '55 and '56 Clippers?

One trick to check for belt noise, with the engine idling and the belts tensioned properly (not too tight or loose), CAREFULLY apply a bar of soap to each side of the fan belt. This will usually quiet a noisy belt at least temporarily.

If it's not the belt, pour a can of water pump lube into the radiator. It will quiet a noisy bearing and prolong lifespan.

Ethanol and brass are listed as having excellent compatibility in the chemical compatibility database. Plastics are a mixed bag depending on what type of plastic. HDPE, PTFE, Nylon and PET are compatible. ABS, polycarbonate, LDPE, PVC, Tygon, Silicone, polyurethane are not.
Interestingly, ethanol is not kind to aluminum either.

In my recently acquired '55 400, the speedometer cable was broken at the trans and as it turns out it's due to the speedometer head turning very stiffly. It doesn't make noise, just takes considerable effort to turn, but does turn and operate, at least until the next cable breaks. I would think it should turn freely.

Any tips on speedometer clean and lube, which I assume requires removal?