Front Spring Positioning Problem
- Thread starter Scott De Shields
- Start date
DICK SPADARO
Well-known member
I feel like this is one of those tests where you rush thru only to find the answers in the front.I assumed that everyone was calling the sway bar a panard rod. After a really close look and a reread RPM has the closest ID on the shackle offset issue. The panard rod is most likely the offender. There is no reason to run a panard rod on a lateral spring installation with a wishbone. Just remove the rod from the axle mount and frame bracket, set the vehicle on the ground , bounce it a couple times and everything should center out.
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Scott De Shields
Senior Member
I forgot to mention that the wishbone had been split some time ago. I had bump steer problems until panhard bar was installed. I am running radial tires.
DICK SPADARO
Well-known member
Ok, anyway to first solve the shackle issue just unhook the panard rod, jounce the car and see if it centers. What happened? If you were having bump steer issues the use of the panard rod may mask a continuing problem. What or whose wishbone split kit did you use?
1931 flamingo
Well-known member
Bump steer: bad king pins, toe-in/out, bad tie rod ends, axle inclination. Are the wishbones adjustable?? Were the steering arms "heated" and bent for clearance issues?? Not sure if i covered e/thing.
Paul in CT
Paul in CT
Are you running stock steering, or has that been updated? I'm seeing a stock axle with what appear to be new k/p's, disc brakes with wider rims and radials and the rims don't have a lot of positive offset, giving a decent scrub radius. Hard to tell from the photos, but it does look like the k/p locks are deep in the axle. The flat end of the lock sits about flush with the front of the axle normally. Did the new k/p's include steering stops or just plain nuts and if only nuts, did you discard those and replace with the original stops? How is the toe adjustment?
Odd that with what appears to be a basically factory Ford engineered front suspension has bump steer. Nothing that is visible here, or that which you have mentioned, would contribute to bump steer.
Odd that with what appears to be a basically factory Ford engineered front suspension has bump steer. Nothing that is visible here, or that which you have mentioned, would contribute to bump steer.
Scott De Shields
Senior Member
I am running a 525 Saginaw box and 15" wheels that my grandfather put on the car. The king pin set came with a steering stop, maybe I tightened it up to much; can I back it out to the front of the axle and re install without hurting the locking ability of the key pin?
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Scott De Shields
Senior Member
I would leave the k/p locks as is, they'll be fine. I had asked about the steering stops because lack of them could allow one to use the internals of the steering box to act as the stops and cause wear. From the new photos it looks like the tie rod and drag link are not much out of parallel so I think you're OK there too. I'm left wondering what caused the bump steer in the first place, things look to be in order.
V8COOPMAN
Well-known member
I'll agree with everyone that the panhard rod should not be necessary on this front-end to make it behave with good manners, and is LIKELY the MAIN culprit in the shackles hanging at DIFFERENT angles. In addition, I believe the RELATIVELY extreme, nearly vertical, downward angle of the shackles is probably more angle than you should be seeing, especially in view of the fact that you still need to add the weight of two fenders and inner panels, hood and grill, which when added will tend to angle the bottom of the shackles outward even more. Look at 19Fordy's example for a realistic shackle angle. Here's what COULD be causing THIS extreme shackle angle situation. You noted that you had split the wishbones, with pictures...not uncommon. As you move the rear of the 'bones outward, as in your case, the perch (shackle) mounts on the front side of the axle move INWARD. They need to be heated and bent OUTWARD to maintain an original dimension between the two, or end-up with a situation similar to what you have now...the main leaf is effectively too long for the NEW spacing (when moving the rear of 'bones outward, WITHOUT bending the front end of 'bones back to ORIGINAL spacing). DD
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richard crow
Well-known member
COOPMAN you were the only one except me that said the hangers were not right. when i answered the split wish bone was not knowed. you are 100 % right .a lot of time guys will ask for help & don,t give all the facts so when some one answers they look stooped . rought exzample 59ab over heats a few days later you find out he has a crosley rad in it. we have some very smart guys on this foruam but you can,t get good advice unless we know all the facts when the question is first asked.one more thing .if your goinging to change the front end set up dick sepadro sells a caster & camber gauge & toe bar which is not expensive & e z to use . a must to get the alliment right
V8COOPMAN
Well-known member
I try really hard not to answer a question or make a comment until I THINK I have enough information to make a reasonably intelligent assessment of the question being pondered, and please realize that I'm aware that I certainly don't know it all. It amazes me the number of folks that DO reply to some serious questions that obviously don't have a clue, or haven't thought-out the rationality of the crapola they just throw out there to increase their post counts. DD
Agree, the spring should be tensioned have to stretch it about 1 1/2" to make up the shackles. Should be about 45 degree angle with car weight on it. Straight down like that bind will occur when spring has to function
Mart
Well-known member
With reference to the shackle angles. there is some mis-information going about here.
I will repeat what I said in my previous post.
Up to 39 ford did not have anything other than the shackles to locate the axle sideways. For these years you must have the correct angle on the shackles (like about 45 degrees).
To improve riding comfort Ford lengthened the spring in the 40 cars. These have the shackles more vertical, because the spring is longer and the perches are the same. To locate the axle sideways, because the shackles are no longer as "stretched" as they were, the sway bar was introduced. This put back the sideways location that was taken out by the less than ideal shackle angle.
In later years the shackle angle was changed even further, to sloping completely the other way, so much so that a sway bar could not locate the axle sideways, so a panhard rod was fitted.
In the example above, the split wishbones have possible slightly reduced the ddistance between the perches, resulting in a more vertical shackle angle. That would be a problem, if no extra sideways location was used, and indeed the poster had to fit a panhard rod to get rid of "bump steer".
Now the poster has also fitted the 40 style anti-sway bar. this offers some sideways location, and some anti-roll resistance too, so is a benefit to have.
In summary, the shackle and spring relationship IN THIS CASE are fine because the sideways location is not trusted to the shackles, but primarily the panhard rod and secondarily the sway bar.
IN THIS CASE the two things are fighting to a certain degree, but due to the limited travel encountered during normal street use, the amount of misalignment between the two is kept within reasonable limits. IN THIS CASE I would recommend setting the car on 4 wheels, and adjusting the panhard rod so the shackles are equal, and calling it good.
I keep stressing IN THIS CASE because each car is different and what will work in one may not work in another.
Mart.
I will repeat what I said in my previous post.
Up to 39 ford did not have anything other than the shackles to locate the axle sideways. For these years you must have the correct angle on the shackles (like about 45 degrees).
To improve riding comfort Ford lengthened the spring in the 40 cars. These have the shackles more vertical, because the spring is longer and the perches are the same. To locate the axle sideways, because the shackles are no longer as "stretched" as they were, the sway bar was introduced. This put back the sideways location that was taken out by the less than ideal shackle angle.
In later years the shackle angle was changed even further, to sloping completely the other way, so much so that a sway bar could not locate the axle sideways, so a panhard rod was fitted.
In the example above, the split wishbones have possible slightly reduced the ddistance between the perches, resulting in a more vertical shackle angle. That would be a problem, if no extra sideways location was used, and indeed the poster had to fit a panhard rod to get rid of "bump steer".
Now the poster has also fitted the 40 style anti-sway bar. this offers some sideways location, and some anti-roll resistance too, so is a benefit to have.
In summary, the shackle and spring relationship IN THIS CASE are fine because the sideways location is not trusted to the shackles, but primarily the panhard rod and secondarily the sway bar.
IN THIS CASE the two things are fighting to a certain degree, but due to the limited travel encountered during normal street use, the amount of misalignment between the two is kept within reasonable limits. IN THIS CASE I would recommend setting the car on 4 wheels, and adjusting the panhard rod so the shackles are equal, and calling it good.
I keep stressing IN THIS CASE because each car is different and what will work in one may not work in another.
Mart.
V8COOPMAN
Well-known member
Mart...I'm going to respectfully disagree with a couple of your above statements. Quickly... '39 and '40 springs are the SAME length.
Sway bars were OPTIONAL on the STANDARD '40 models, and installed on ALL DeLuxe '40 models. With that being said, I have to now wonder what kept the '40 Standards WITHOUT the sway bar from "swayin' in the breeze"? I will add this...my '40 DeLuxe coupe with stock-height axle, reversed-eye spring, stock sway bar, split wishbone mounted and spread in the rear EXACTLY as the subject car's pictures indicate, WITH the front end of the bars being "tweaked" back to original spread dimension, and with the shackles resting at roughly a 45° angle (similar to 19Fordy's picture), has seen the north side of 100 mph on rare occasion WITHOUT ANY undesirable handling issues...no bump-steer, nada. I'll say again, there should be NO reason for the need of a panhard rod on a properly set-up '40 front end. DD
Mart
Well-known member
Thanks DD, I was going on my personal experience with my own 40, the spring that was on the car was pretty tired and the car was too low, the shackles were near vertical and easy to remove. I replaced it with another spring that was shorter, much stiffer and once fitted the shackles were at 45 degrees. I assumed the original spring was a 40 and the other spring pre 40, which it was, but it may not have been a 39.
I agree re any 40 without the sway bar, and in fact I just bought one to go on my 41 pickup.
In the original poster's case, I'd still say just adjust the panhard and drive it.
Thanks for the discussion, sometimes when writing all this stuff, it's easy to think no-one reads it properly.
Mart.
I agree re any 40 without the sway bar, and in fact I just bought one to go on my 41 pickup.
In the original poster's case, I'd still say just adjust the panhard and drive it.
Thanks for the discussion, sometimes when writing all this stuff, it's easy to think no-one reads it properly.
Mart.
V8COOPMAN
Well-known member
"Thanks for the discussion, sometimes when writing all this stuff, it's easy to think no-one reads it properly.
Mart."
Cool, Mart! Interesting, thought-provoking discussion. Hopefully, we're all here trying to help the OP with the totality of his problem. I still believe his problem lies deeper than just "band-aiding" it with a panhard rod. His eventual list of ALL symptoms and specifics, along with the helpful pictures, did well to warrant realistic analysis. I still believe that "band-aiding" with a panhard rod is not the answer on a '40 Ford. These front ends are not "rocket science" geometrically. Something more is going-on here. DD
Mart."
Cool, Mart! Interesting, thought-provoking discussion. Hopefully, we're all here trying to help the OP with the totality of his problem. I still believe his problem lies deeper than just "band-aiding" it with a panhard rod. His eventual list of ALL symptoms and specifics, along with the helpful pictures, did well to warrant realistic analysis. I still believe that "band-aiding" with a panhard rod is not the answer on a '40 Ford. These front ends are not "rocket science" geometrically. Something more is going-on here. DD