Just took my newly built 24 hack for first ride, it was all over the toad. Really bad, could not keep it strait. When one wheel looks straight the other appears to be taking a left. How do I align this?
The front edges of the front wheels should be 3/16" to 1/4" (Going from memory here so somebody correct me if I'm wrong) closer together than the rear edges. This is known as "Tow in". So, if your left wheel is pointed dead ahead, your right wheel should point ever so slightly to the left. If your right wheel is pointed dead ahead and your left wheel points to the left, then you have "Tow out", which is incorrect. The adjustment is made by screwing the yoke on the right hand end of the tie rod in or out until you have the proper adjustment.
Bill -- Since the car is newly-rebuilt, I will mention this: The axle should be tilted toward the back at the top, not forward. If you had the axle with its spring perches out of the car and put it in backwards (it will go either way), it will tilt forward, not back. That will cause it to dart from side to side. (The tilt is built into the perches.) As Hal mentioned, toe-out will also cause that, and it's easy to remedy.
Look at the top of your spring perches. You will see a little nub on top with a dimple in the center. That nub should be towards the back of the car. If not installed correctly the axle alignment will be off and the car will be difficult to control.
Stephen
And it's know as "toe in".
Eye no, wee ahr knot supposed two notice other peep holes miss takes.
Bill,
Like has been said, check your caster as in:
http://www.mtfca.com/discus/messages/179374/208098.html?1303883023
The spring purchases could be reversed but it is really the wishbone that holds the caster angle.
Jim
Jim,
Your roadster looks like you are doing a great job on it. Keep up the good work.
For safety reasons, I believe I need to respectfully disagree with the comment "The spring purchases could be reversed but it is really the wishbone that holds the caster angle." My understanding is "IF" the parts are to original Ford specifications you can install the spring perches on opposite sides and the car’s caster will be negative and the car will be dangerous to drive. That is supported by the instructions in the Ford Service and other manuals.
"IF" the parts are not to original specifications -- i.e. if someone shortens or lengthens the wishbone arms – (add or subtract metal -- bend them (not recommended) etc.) you can also change the caster. As you noted in your posting at: http://www.mtfca.com/discus/messages/179374/209504.html?1304663515 your wishbone was bent and did not match up well to the spring perches. But you also noted that you needed to swap the spring perches since they were installed improperly. I believe if you were to swap the spring perches (i.e. install them wrong) today – even with your straightened wishbone your car would have a negative caster.
Note the diagram above and how the hole in the top of the spring perch would be parallel to the spring shackle and frame while the lower shaft that fits into the front axle is off center (by that mathematical 5 1/2 degrees – which so far folks have not been in agreement on if it is or isn’t 5 1/2 degrees -- I looked for the previous posting on that -- but couldn't find it again. But mathmatically the angle and the amount of distance the Ford Service says to check it doesn't all line up with the math). But regardless the spring perch tilts the axle positive or negative depending on how they are installed if the other parts (including the spring and frame) are to factory specifications and not bent out of shape. There have been a couple of postings where the car was really squirrely to drive and they discovered the spring perches were installed incorrectly. Swapping the spring perches corrected the problem. And of course there are other times when the spring perches are installed properly but something else is wrong and causing the issue.
Note the posting by Robert at: http://www.mtfca.com/discus/messages/80257/80333.html?1233523419
had the spring perches installed wrong (swapped) on his 1916 (that did not have the bosses on the spring perch) and when he corrected that he posted in the same posting:
By Robert Kiefaber on Sunday, February 01, 2009 - 03:51 pm:
Thanks to all! I am once again humbled by this machine. The perches were on backwards, and now it has been corrected. Everything now looks as it should . Having no bosses as a guide threw me.
Back to Hap again: Of course if I got that wrong – it won’t be the first time and certainly won’t be the last time.
For additional details on front axle set up please see: http://www.mtfca.com/discus/messages/29/40382.html
Jim, thank you for all your inputs and your support to our club. You are encouraging a lot us with your before and after photos of you roadster on your profile page. And your comments encourage discussion and thoughts and 99.9% of the time are right on target. Thank you!
Respectfully submitted,
Hap l9l5 cut off
Hap,
We are pretty much in agreement, the spring perches should be installed correctly.
However if they are installed correctly and the caster (pitch) is off, it is the wishbone that that must be bent to adjust the caster angle. The service manual states the the axle must be tilted to adjust the caster. This tilting bends the wishbone. This make sense because the springs flex but the connection between the axle and wishbone is fixed and controls the caster.
Here is a photo of my before and after wishbone. Mine was way off and there is no way to get the correct caster without bending or replacing the wishbone. I chose to bend it as the service manual recommends. I have no idea how it got so far off or if it was drove, how they kept it on the road but that was 1/2 a century ago.
Jim
Thanks for all the input. The spring perches were reversed, I swapped them, no difference in driving. I replaced the tie rod bushings and tightened the steering linkage, had to put a shim under one cap, still no difference, guess I'll have to adjust tie rod end for toe in.
The first thing that should have been checked is the toe in. If it tows out, the car will wander. Also if the bushings are too tight it will not self center as you drive along and you will have to pull on the steering wheel to straighten it out. Fortunately, you can adjust for the toe in. It is not a very accurate adjustment. You have to make a complete turn of the tie rod end to adjust it. You should get it to toe in slightly. If you adjusted the spindle bolts or re-bushed them, try removing the cotter pin on the jam nut at the bottom of the axle and loosening the nut. Then turn the spindle bolt at the top of the axle one quarter turn looser and tighten up the jam nut and replace the cotter. That should loosen things up and on a level road (best on a parking lot) let go of the steering after making a turn while still moving forward and it should self center. If the wheels shimmy, you loosened it too much.
Norm
Bill,
Yes, you need to check your toe in.
Did you check your caster (axle pitch) before and/or after you reversed the perches?
Did it change after your reversed your perches?
Really the caster is not rocket science. With just a quick glance you can see if the axle is tilting back as it should be. If it is straight up or tiled forward, you will have tracking problems.
Jim
Jim, it looks like I will have to bend my wishbone opposite of what you did. I have not checked it with a square, but it looks like the bottom is more forward .
You shouldn't need to bend your wishbone on a later car with the wishbone mounted under the axle. The spring will hold the top of the axle and the wishbone, the bottom. Only adjustment which can be made is either the arch of the spring, or bending the axle between the spring perch and the spindle.
Norm
When I first got my current boat-tail back on the road, I barely got it running in time for the SCVMTFC Endurance Run. The entire test drive was loading the car onto my trailer. I had noticed that the caster was way too much. But I didn't have any time left to work on it (I made it to the tech inspection with about fifteen minutes to spare).
It turned out, the car drove fine under about 20mph. Any faster, and it became very difficult to turn the wheel. It wanted to go straight ahead. We finished that run (dead last) after fixing a bunch of minor breakdowns (got the "hard-luck but finishing the run" trophy). It is always best to shake the bugs out before your major tour.
The caster problem was caused by putting some Laurel-type lowering brackets onto the front axle. They shifted the geometry around resulting in the added caster. After the run, I bent another wishbone and changed it. It has driven nicely ever since.
I like a little more caster than T specifications indicate. My experience has been that they drive a little better, straighter, and shimmy less than a T that has spec caster. However, the point of all this is, too much caster will result in a different set of difficulties with driving.
Toe-in is also critical, more so. You must have no toe-out whatsoever. That will result in squirrelly steering and probably shimmy (also tire wear). Any more than about a quarter inch of tow-in will wear tires out faster than you would want to believe possible, as well as shimmy and squirrelly steering.
Another possible cause of steering issues to check. The camber of the two spindles need to match. Over the years of T production, there were various minor changes in the spindles, some of them resulting in variations in the camber. If a spindle got changed at some point through the years, it may not have been a good match for the other one.
The easiest check, is to use "straight edges" to line up the wheel/tire and the king-pin. The difference at the same height needs to be the same for both sides. And the placement of the tire on the ground relative to the king-pin needs to be the same on both sides. It can get tricky. I have known T owners that never could figure why, but one perfectly good looking spindle worked well while another did not, both against the same one on the other side.
This is after checking everything mentioned in other postings. After you know everything else is good and snug and facing the right direction, then wonder about matching spindles.
Drive carefully, and enjoy, W2