Thread: Cross member from 95 Roadmaster in 1937

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The main concern will be setting the car at ride height with the proper rake or level or Kentucky hillbilly look front to rear. That's what you're after, right, THE RIGHT LOOK?

OK, first, find a '95 Roadmaster that's in your neighborhood and currently running on the street (or maybe an example in a used car lot that the owner will let you look at). You will want to take some measurements and angles off the control arms and their relationship to the crossmember as the car sits on its tires and wheels. Ideally, you will be able to drive the car to a shop that has a drive-on hydraulic lift. That will allow the car to sit squarely front to rear and left to right on its tires and allow you to get underneath to measure everything. Some measurments may have to be taken from under the hood also, like laying an angle finder on the upper control arm to determine front to rear angle as well as well as lateral angle.

What you want to find is the angle of the upper and/or lower control arms in relation to a part of the crossmember itself when the vehicle is "sitting at the curb". You'll want the car sitting on a flat, level surface with the front tires inflated evenly left to right. Factory-recommended air pressure doesn't matter much, as long as both front tires have the same pressure and are the same size and brand. The car must be level left to right, so crawl under and place a level on the underside of the crossmember to make sure it is. If not, drive it onto a shim such as a piece of 1" x 6" x 6" wood, or 2 of them or 3 of them. Whatever it takes to begin with a level car, side to side and front to rear as produced by the factory.

With the car at ride height and leveled, use your angle finder, levels, straightedges, mason's string and any other tools you have to find a relationship between the upper or lower control arm and the crossmember. You'll also want to know the angle of the crossmember front to rear. With the angle finder on the flat part of the underside of the crossmember, what is the angle? Zero? 1 degree up bubble to the front? 1 degree up bubble to the rear? With the angle finder on the underside of the lower control arm, what is the angle? Zero? 1 degree angled up to the tire? 1 degree angled down to the tire? You may have to position a piece of wood under the control arm to have a flat place to put your angle finder. If you have to do this, keep the piece of wood you used and pay very close attention to where you positioned it on the control arm so you can replicate the position later on your own control arm. What is the distance from the center of the front spindle to the ground? What is the size of tire on the car you're measuring?

Once you have every conceivable angle and measurement written down, you will be ready to replicate the angles on your front clip/crossmember. Put the whole mess together (sans springs) using whatever materials you need to, so that you will have a crossmember/control arm unit that replicates the running car that you took measurements and angles off of. Make two stands, one for each side, that will allow the mess to sit on the spindles at exactly the radius of the tires you intend to use. In the past, where the shock goes through the middle of the coil spring, I have used 1/2" Allthread to replace the shock and tie the whole mess together so that the upper and lower control arms replicate the angles found on the car you took measurements and angles from. Do whatever you have to do to lock the control arms into stock ride height position/angle in relation to the crossmember.

Now, sit the '37 on a flat, level surface with jackstands under the car at the firewall and trunk area. Ideally, you would have the car up on a jig, but I have done this whole operation on a concrete floor in the past, building a plywood floor up off the concrete with shims to make the pad level side to side and front to rear. The last time I did this on a concrete floor, my shims started off at zero at the left front and ended up with over 2 inches of shim at the right rear. That's why you don't want to build off a concrete floor. It isn't level by any stretch of the imagination. This is where you make or break the whole project, getting the car level and at exactly the ride height you want in your finished product. I have also found it helpful to rig up the front fenders temporarily, so that you can eyeball the front to rear position of the tire and wheel in relationship to the wheel opening in the fender. You don't have to build to any particular wheelbase at this point. Wheelbase does not matter. What you want is the tire and wheel looking the best front to rear in the fenderwell, as you view the car from the side. The car might look better with the front tire 1/2" further forward or 1/2" further to the rear than the stock '37 tire was in the fenderwell. This is all a matter of what pleases YOUR EYE. Years ago, I determined that ground clearance should be held to 4", so keep a 4" x 4" block of wood in your shop for sliding around under the car when you are building it. Keep everything above the block of wood and nothing will scrape when you are driving down the road loading and unloading the suspension.

You will want to find points of reference on the '37 frame that are the same front to rear, like maybe a rear spring eye or some other hole that is the same front to rear on both sides of the frame. Drop a plumb bob from these reference points to the floor and make a mark on the floor on each side, then snap a line between the two marks so that you have a chalk line across the car from side to side. This will be the line from which all other measurements will be taken and will establish a line to measure from for installation of the differential housing. Now, use your 12 ft. tape measure, make a mark at the front of the car that is 12 ft. from your reference line at the rear. Measure from rear to front at two points, then snap a chalk line across the marks. Now, you have two reference lines that should be 12 ft. apart and exactly parallel with each other. If 10 ft. works better to put you in the vicinity of the spindles, use that. If 11 ft. works better, use that. It doesn't matter. You are just trying to lay a line at the front that you can measure from later, that is perpendicular to the (front/rear) centerline of the car and parallel to the rear reference line. Measure on an "X" at both sides to make sure you have the marks exactly parallel. Measuring from your original drop points at the rear to the center of the line will allow you to make a mark on the rear reference line at exactly the center of the car. Do the same at the front. Connect the dots with a fore/aft line. Now, from a bird's-eye view, you should have a set of lines that look like a capital i (I). These lines will allow you to drop plumb bobs from other parts of the frame/body to measure from.

Slide the front clip up under the car and raise it little by little until you get it at ride height and are able to attach your stands to the spindles. Drop your plumb bob on each side down to your lateral reference mark to get the clip square in the car. Now, it's just a matter of "trim and try", "trim and try" until you get it right. Then weld it in and move to the rear of the car to do the same with the rear differential. Do not weld anything to anything until you have measured your work several times and even had another set of eyes to look over what you're doing and agree with you that the whole mess is square. MAKE ABSOLUTELY CERTAIN THAT YOU REPLICATE THE FRONT TO REAR ANGLE OF THE BOTTOM OF THE CROSSMEMBER THE EXACT SAME AS IT WAS ON THE CAR YOU USED TO FIND THE ANGLE IN THE FIRST PLACE. Failure to do this will change caster from the as-designed-by-the-factory spec to some fosdick spec that won't work.

One of my buddies came by the house one day to show me his latest purchase, a '56 Ford pickup (Effie). It was absolutely gorgeous, BBC, 8-71, two fours, flawless turquoise paint and turquoise and white leather interior. I accepted his offer to drive it and it was one of the biggest disappointments ever. Whoever had installed the front clip had failed to take the front/rear angle of the clip into consideration, welding it into the truck with ???? caster angle. When you turned a corner, the truck had so much negative caster that you had to manually return the steering wheel to neutral. AAAARRRRRGGGHHHHH. No way to fix it without cutting the whole front clip out and re-positioning it. JUNK. He paid $35,000 for junk.

Using my instructions, you will end up with a front suspension that sits properly in the car, at the ride height you have determined for yourself. There will be no need to cut springs or use dropped spindles or any other such FOSDICK crap that seems to be the norm with builders who have no idea what they're doing in the first place. The car will turn corners, start, stop and handle exactly like a stock '95 Roadmaster. It will have the smooth Roadmaster ride, not some choppy, fosdick ride like you get with cut coils and the steering wheel will return to neutral on its own accord following a turn. The finished weight of the car should be close to what the '95 is, but if it turns out a little lighter or a little heavier, you can call up Eaton Detroit Spring and have them supply you with a lighter or heavier RATE spring that will allow the car to sit stock and ride like the '95. The key here is to pay attention to your angles and replicate stock.

I don't want to confuse you, but will add a tutorial that I wrote several years ago for a fellow who was using Dakota pieces on an old International pickup.......
http://www.crankshaftcoalition.com/wiki/Frame_swaps

Keep those cards and letters comin' in, I seldom get tired of answering questions for those who really want to learn.