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Lining up a new front end...how would you do it?

PotvinGuy

Well-Known Member
Staff member
Here is where I am with my new front end:
spindles%25202015.jpg

Now...how do I get the two sides pointing straight ahead so I can finish drilling holes? Axle is level and rack & pinion is centered. No wheels and tires yet, just the spindles with the caliper mounting plates. I have a couple ideas, but want to hear what you come up with.
 
Here is where I am with my new front end:
spindles%25202015.jpg

Now...how do I get the two sides pointing straight ahead so I can finish drilling holes? Axle is level and rack & pinion is centered. No wheels and tires yet, just the spindles with the caliper mounting plates. I have a couple ideas, but want to hear what you come up with.

Measure to the middle of the rear frame cross member. Put a mark. Measure from the end of each spindle to the mark at the rear cross member until you have the same measurement by adjusting the spindles.. Ass u me ing your frame is square, and not be dog tracking, the rest will adjust out when you align the front end.
 
Here is where I am with my new front end:
spindles%25202015.jpg

Now...how do I get the two sides pointing straight ahead so I can finish drilling holes? Axle is level and rack & pinion is centered. No wheels and tires yet, just the spindles with the caliper mounting plates. I have a couple ideas, but want to hear what you come up with.
I think I would mount the rotors and use a strait edge, magnetic if possible, or clamped to extend enough to measure fore and aft so it could be centered. It is important to keep them at the same level, and keep them level, so the measurement is at the same point relevant to camber, caster.
 
I think I would mount the rotors and use a strait edge, magnetic if possible, or clamped to extend enough to measure fore and aft so it could be centered. It is important to keep them at the same level, and keep them level, so the measurement is at the same point relevant to camber, caster.
Trying to envision your idea. Clamp a straightedge to each rotor and then measure...from where to where?
 
Trying to envision your idea. Clamp a straightedge to each rotor and then measure...from where to where?

Get two aluminum or lite gauge steel angles about 36 to 48" long. At the center line mark of those angles lay them above the spindle shaft or pin and clamp them to the flat flange surface. then you can get them parallel by making a number of width measurements. I like to measure diagonally also just to double check myself. Hope this will help you out. Have fun.

George
 
Get two aluminum or lite gauge steel angles about 36 to 48" long. At the center line mark of those angles lay them above the spindle shaft or pin and clamp them to the flat flange surface. then you can get them parallel by making a number of width measurements. I like to measure diagonally also just to double check myself. Hope this will help you out. Have fun.

George
That would get them parallel:
lining.jpg


...but not necessarily straight ahead?
 
That would get them parallel:
lining.jpg


...but not necessarily straight ahead?


That is why I said to measure between the straight edges at both ends. That would bring them to equal distance from one end off the straight edge to the other. Then measure it diagonally from both end corners and check to get a like number. Once they match you now have two right angle triangles and should be square. Be sure to reference a center point at the spindle center line and make all of your width and diagonal measurements at equal distances from that mid point. The nice part about using aluminum is you can mark on it with a mechanical pencil. I use this method for many things on my flat surfaced chassis tables when rebuilding new suspension systems. Any questions please let me know.

George
 
Ah, I see it now, Fluid. Very nice. Anyone else care to play before I reveal my ideas?
 
Ah, I see it now, Fluid. Very nice. Anyone else care to play before I reveal my ideas?


One thing I failed to mention...This all works as long as the front axle is installed perpendicular to the frame center line. But having seen your car up close and personal I didn't feel it necessary. So you other eagle eyes remember to put your axle in square and centered. Just take your time and measure carefully then measure again. And before your buddy drinks that beer have him measure it. Hell have the dog measure it. One other pet peeve of mine. I have never seen a vertical mill or an engine lathe with fractional makings on the feed dials. Never saw fraction micrometers. So through those damn harbor freight tape measures away and get one that reads in tenths and thousands. So much easier when doing close and precision layouts like suspension work. I also don't weld metric but that's another battle. Now get to work.

George
 
One other pet peeve of mine. I have never seen a vertical mill or an engine lathe with fractional makings on the feed dials. Never saw fraction micrometers.

I know what you mean. Having done machine work for so many years, I find myself mentally converting most measurements to decimal. It makes working with the machines easier and I've just gotten used to thinking in thousandths.

Mike
 
For your purposes right now, you want it straight ahead (parallel to the centerline of the frame) right? I would use the straight edges like George mentioned, but run a string tight down the centerline of the frame. Then use those straight edges to measure to the string front and back. No need to do diagonal measurements. Not that diagonal measurements are bad, but it would require that the straight edges side to side are exactly the same. If you do it with the string, the straight edges need only be exactly 90 degrees to the spindles.

And yes the axle needs to be perfectly centered and perpendicular to the frame, but that's easy enough.
 
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Like this...

bobs66440...Yes, a string on the center line is another good way to reference things. I always build off of a center line either scribed in the table top or a silver lead line. But I still always make a couple of diagonal measurements just to keep myself out of trouble. When I was still building Top Fuel dragsters I put a surveying transit at one end on the center line and shot to a vertical plumb line tool that bolted into the table. I could check anywhere on the table or car in either a horizontal sweep or a vertical move and verify the true CL of any part. That transit will also bolt into a 14ft table that I prototype the road racing sports cars. After all that I still triangulate at various points just to check myself. I'm not suggesting that anyone here go to this much trouble as it's not necessary with these type of cars but it can't hurt and it does take the "I wonder if it's right worries" out of your late night sleep thoughts. As they use to say, "Close is only good in horseshoes and hand grenades!" Have fun!

George
 
I know what you mean. Having done machine work for so many years, I find myself mentally converting most measurements to decimal. It makes working with the machines easier and I've just gotten used to thinking in thousandths.

Mike

Mike...Decimals are for precision driven people, Fractions are for carpenters, Liters are for Whiskey Drinkers and Metrics are for trouble makers. I like decimals and liters!
 
I'm still working to test my two odd ideas, so all you gearheads still have time to chime in. Stay tuned.
 
...and one of the odd ideas allows for aligning each side by itself, and requires only one tool you might have already. A hint: it's digital.
 
You can get a laser level that's used for aligning picture frames, wall studs, etc. very cheap. It will project a very sharp line on a wall or whatever so you can measure accurately. Clamp one on each rotor and make sure the laser lines on the wall equal the rotor face-to face distance. I have used this method to check my alignment and it works quite well.
 
I've used two strings. On one side, attach the string to the rear end just inside the tire, wrap around the back and outside of the tire and pull towards the outside of the front tire on the same side. Make sure the string is lined up with the center line of both the front and rear wheels. Extend the string about 4 feet in front of the car and use a chair, blocks or whatever so it is tight. Do the same thing on the other side of the car. Now measure the distance between the two strings just in front of the front tires and out at the end of the strings. Using this method you can increase or decrease the distance at ends of the strings to play with different toe-ins and toe-outs. Make sure the distance from the outside of the front wheels to the strings stays equal to avoid getting out of parallel. Simple. This worked for me and helped eliminate the death wobble in my T.
 
When I built dragsters (aka NHRA Jr. Dragsters) I used string, 12 pound fishing line. Then I got a laser. I soon came to find that the laser that I could afford had a +/- of about .250 inch out at 25 feet. We tried a 2 power rifle scope to align Bell Helicopters 206 and 212 main rotor heads, but we fell back to the string method. getting the precision out of the scope mount was difficult.
 
You can get a laser level that's used for aligning picture frames, wall studs, etc. very cheap. It will project a very sharp line on a wall or whatever so you can measure accurately. Clamp one on each rotor and make sure the laser lines on the wall equal the rotor face-to face distance. I have used this method to check my alignment and it works quite well.

You would need to make sure the frame was perpendicular to that wall would you not?

George
 

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