body fit ~ stepdowns

I’ve had a lot of old-time, knowledge Hudson guys do the slow, low chuckle when talking about panel fitting on a Hudson, in particular on a step-down. After the chuckle, there was always some comment like, “Yep! Sounds like a Hudson.”

IMO, Step-downs (all I can attest to) have some of the worst fitting and ill-gapped sheet metal of any production car I’ve seen. That said, there’s a lot of variables that go into that statement that one has to take into account.

Firstly, remember that blocking out panels, setting the gaps to exactly 1/8” (or whatever), is a modern, usually high end shop technique that has been taken to the extreme, particularly on the over-restored show and trailer queens. Originally, these cars didn’t have ANY of that fussiness done to them. From a production standpoint, there simply wasn’t the time or the money to be wasting on the line. The ONLY production car I know of that had that kind of lavishness given was a RR. No American mfg. that I am a aware of, went to such extremes. What was close? I don’t know, I wasn’t there, but I’m reasonably sure that if it was ¼” max. gap, and within ¼” laterally, it was “good enough”. Sounds pretty far out there, though, doesn’t it?

Secondly, one must remember that immediately after a flat piece of steel is stamped into a different shape, i.e., a door, fender, quarter, decklid, whatever, it is under stress. The stress never goes away, a week later, or decades later. What happens is that body panel continually fights to get back to it’s original shape, which means that it changes as time goes on, from where in space it once was. The more time that passes, the more it has changed. Some will change more than others, due to the nature of the metal to begin with, the atmospheric and geographic location of the part, how much wear and tear it’s been exposed to, etc. An automobile that has seen limited use, has never been “adjusted”, taken apart, or molested in any way, will have panels that “fit” differently than the day they did when it came off of the line. It is absolutely inevitable and unavoidable.

OEM quality is an amazing and necessary technology that the automobile companies have been employing for decades. In it’s most basic application, it means that you can take a door off of the rack and put it on any body that it was designed for and it should fit with minor adjustments. Most of the time, that’s exactly how the process works. It works better on replacing water pumps that it does a fender, mind you—too many variables. Which brings me to, Thirdly, a set of dies that were manufactured to make a quarter panel for a 2DR Step-Down, let’s say, might be good for 10,000 stampings. The reason they have a “limit”, is the metal on the dies starts to break down, change shape, and “wear off (or out)”. Eventually, whatever tolerances the engineers set for the discrepancy between the first stamping and the 10,000th stamping have reached maximum allowances. I don’t know for certain, but my guess is the difference is not in the thousands-of-an-inch, but more like ¼-3/8” difference. Fender #1 of a new set of dies is not going to be the same as Fender #9567. There is simply no possible way.

So, that’s only three factors that go into the relationship between two adjoining body panels on a 60+ year old car. There are others, but those cover my objective. Question is, what can you do? My opinion is based only on my experience and success ratio, nothing more. Because the old tin has “slow-changed” over time, you have to shock it back into shape. If you have a door that is twisted beyond what can be adjusted out with the factory adjustability limits, the solution to remove the twist not to do the elephant leaning on the tree till it bends technique, but, rather to instantaneously “shock” the door back to where you want it to be. Moving it slowly will only allow it to get back where it “wants” to be in a short amount of time, sometimes even in a few days.

If you are in the middle of bodywork, go ahead and lead some of the gaps in, or shave some off of a high spot, whatever it takes. Do some panel fitting, but don’t go over the edge. You’ll drive yourself crazy, the car was never “perfect” to begin with. My advice is to set some parameters that you will be happy with and stick to it. Don’t over-restore, it’s metal, not poured plastic.

dougson wrote:

A lot of useful information, thanks all. After fighting with the hood, shiming the hinge, wrestling with right front fender, and installing the hood latch and rubber guides, everything actually looks pretty good. The hood clears the vent without a big gap, and the gaps on each side are now pretty good. The only remaining issue is the driver's door, which has about a 1/2" space along the leading upper bend. May weld in a 1/4" strip and finish.

Sounds like a good plan. I had to lead in one side of the cowl on the 'vert. My gap wasn't quite as big as yours, but I had those kinds of gaps elsewhere.