just put my 1934 ford pickup on the ground for the first time.i did cowl steering using a bmw box with hiem joints on both ends of the drag link connecting to the backing plate of the 1941 axle.when in the air every thing seemed to work great. when on the ground as the steering wheel turns and the pitman arm goes thru its swing you can see the frame being raised and lowering with the swing. doesnt look right but can not see how to have it not be this way. this is my first time with cowl steering. is this normal or is something wrong?
Have any photos of the whole setup? It almost sounds like something in the steering/suspension is binding up when the weight of the car is down on the wheels.
Any car with king pin inclination and/or caster in its steering geometry ( almost anything newer than the mid teens ) will rise and fall relative to the ground a little as the wheels move lock to lock. Hope that is what you have
If you have a lot of caster, the front of the car will lift slightly as you approach each lock, due to the contact point of the tyres relation to the king pin changing. if this is what you are seeing its normal. if you mean the frame you built to house the steering box is moving, relative to the chassis.. thats not so good, means its under built, or a poor design.
dont have pictures yet but will try to post some soon. the frame work i built that holds the box is very stout and does not seem to flex at all. the pitman arm when centered at its lowest spot is 20.5" off the ground and 19.75" at the highest part of its swing. this how much the frame rises and lowers.
Kingpin axis inclination, the angle between the kingpin (or the balljoints) and the spindle, will cause a car to "lift" as you turn the wheels thru their arc. This helps provide self centering and reduces turning forces by allowing the wheel to pivot closer to the contact patch of the tire (if the wheel offset is correct).
I used a BMW box & experienced severe cowl flex before building a better mounting system. Never had any other issues with it though. JH
Id get it on the road and see how it is driving. Most cowl steering problems comes from Flex in the steering box mount. If your draglink slopes down to the front of the car then when you turn the wheel it will lift the car a little. Check your caster, but I assume since your building cowl steering you have your axle at 6-8 degrees. This car does the same thing.
I am building a T also with cowl steering,,, does your current mount in the pictures flex? it looks pretty beefy ftom the pictures. Thanks Ron
I have cowl steering on my T, and I have 10 degrees of caster. My car does the same thing you describe, and there is no problem with it. The car steers fine and goes strait as an arrow.
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