MTFCA Forum

The springs on my 27 Roadster have been re-arched and I suspect they are higher than normal now, at least that's the way it looks to me now.

From the floor to the bottom of frame rails I get the following measurements:
Front 22 3/4"
Rear 23 55/64"

Additionally, the right front running board bracket measures 1/8" lower than the left one. I was thinking about bending it upwards to compensate. Bodywork is not my expertise but I suspect that would require heating the bracket to red hot. The frame has already been painted so maybe it'll be more practical to shim the wood spacer up and be done with it.

Can someone confirm their chassis height on a similar model?

Accurate reference points, such as a perfectly flat floor, are hard to come by. 1/8" on the runningboard is probably within tolerance, and things like tire pressure, tread depth, and more can affect things more than that. Moving the car, or gving it a good shake, might change it more than that. If you do want to adjust it, I'd suggest shimming it. Your new springs will settle some after a couple of hundred miles of driving. It's normal for new springs to increase the ride height. Passengers or other loads, including fuel, will affect ride height. How tightly and how evenly the springs are clamped to the crossmembers will affect measurements.

My '27 roadster measures about 1 1/4" lower than yours. It has at least several thousand miles on the springs, and maybe a good deal more than that. My car is sitting on Lucas 4.40/4.50 X 21 tires on Ford wire wheels. The car has no bumpers. It has a starter and battery, full tank of gas, and the spare wheel/tire is in the trunk. Just looking at my car and comparing it to pictures of other similar cars, I'd say my car is probably riding just a little lower than an identical brand new car, or a car with new springs, would. My tires are techically underinflated at 25 PSI. Putting 30-35 PSI in the tires would raise the car. Tire diameter varies among tires of different brands of the same nominal size. Most Model Ts , and many other vehicles, will have a slight lean to the left or right if parked on a perfectly level surface. Rocking the car side to side will change the slight lean, or cause it to lean the other way. This is normal, and is due to friction between the spring leaves and friction in other chassis parts. Clean, well-lubricated springs minimize this tendency. To sum up, I'd drive a car with new springs for at least a few hundred miles, then re-check all spring clips and other hardware and tighten as needed. I'm pretty sure you'll find the springs will settle somewhat and probably will become a little less stiff as the spring leaves wear-in. There are extensive discussions on this forum relating to spring lubrication.

I assume you are measuring a complete car, and not just the running gear, as pictured, without the body, engine, etc. Any and all weight added to the chassis will lower the ride height.

Eric

Here is a sketch of factory dimensions for the chassis only on the Improved Car, this may help some.





Click on image to enlarge.

Thanks for your input gents. It's good to know that the springs will settle in a bit after driving. I filed them down, leaf by leaf then painted them with black enamel paint with powdered graphite mixed in. They have a wonderful movement I haven't seen in decades (they hadn't been lubed for at least 40 years).

My concern with the height came about when I bolted a rear fender up to the trunk and saw how much room there was from the top of the tire to the fender (about 8 inches). It's true that some parts still have to be bolted onto the car so there will be a little more weight to pull things downward.

I searched for chassis dimensions drawing for the improved car but only found the one for earlier cars, so thanks for that Dan. That will make things easier to measure and check.

Your car appears to be within about 1 1/2" of the chassis height on my car. That's well under a 10% difference, which I think is no cause for alarm with new or re-worked springs. I think you'll find that a few hundred miles and full operating weight will reduce the chassis height to within the normal range, if it isn't already within that range. Keep in mind that tire sizes vary, and my tires may not be as tall as yours. They probably aren't, since they have significant tread wear and are not fully inflated. Model Ts were designed to be used, and typical ride height of a '27 roadster would probably be obtained with 2 adult passengers and 100 lbs or so in the trunk. Loading affects both ride height and wheelbase, and will affect the position of the tires in relation to the fenders, both as to vertical clearance and the spacing front to rear of the tire within the fender. A fully loaded T has a longer wheelbase than an unladen one.