I guess I'll make my own bumpsteer kit.

Hey Guys and Gals,
I lowered my '65 Galaxie a bunch by cutting the springs front and rear and now have an extreme bumpsteer problem. At about 25 MPH, she starts to dart all over the place with the slightest bump. When I put the stock height springs back in, it goes away 100% and drives really well. I assume the problem is because I severly changed the angle of the tie rod. At stock height, it points down to the steering arm, from the center of the car. At the lowered height, the tie rod is about parallel to the ground.

The front end is totally rebuilt with all new parts and the toe is set as is the caster and camber.

I bent the steering arms down a couple of inches figuring this would lower that end of the tierod but it didn't help much.

Of course nobody makes a bumpsteer kit for Ford Galaxies. But I think I can make my own.
I found these on Ebay and ordered a set of two.

They have the same big end of the taper and the same small end of the taper, I just don't no if it tapers at the same rate. I don't know if I am thinking about this right, but it seems to me that just because the end measurements (the big end and the small end) are the same, that alone does not mean they are the same taper.
I ssume one taper could take 1 inch to go from 5/8 to 7/8 and another taper could take 2 inches to cover the 5/8 to 7/8.
Does this make sense? Am I thinking about this correctly?
These and two 5/8, LH thread, male heim joints from Speedway Motors will replace the tierod and hopefully it's mounting point at the steering arm.


I hope this works. I can't drive it as it is.
Thanks,
Steve

 

I really can't see what you're doing with those bolts and heim joints?
Darting is not a "function" of bump-steer, it usually indicates a zero in the caster department.
Bumpsteer usually means if the road wheel moves up or down in the suspension arc the steering is forced to turn.

 

hey pasadena, thanks for the reply.
i assumed it was a bumpsteer problem because when i put the stock height springs back in there (really raises the car back up), the darting goes away. i assume putting the stock height springs back in there doesn't change the caster any. but it definitely changes the angle of the tierod (points down from the center of the car to the stering arm at stock height and with the car severely lowered, the tierod is about level with the ground.

the tierod wants to point down to the steering arm. seems to me you either have to raise the inside of the tierod to get some angle downward towards the steering arm, or lower where the outer end of the tierod attaches to the steering arm (bending the steering arm down or using a bumpsteer kit, or both)

this kit will lower where the tierod attaches to the steering arm. instead of a tierod end on there, it'll be a heim joint that i can lower on the bottom threaded part of the tapered part that goes into the steering arm.

it's hard to explain. check out some "bumpsteer kits" online and it'll give you a better picture of my homemade one.

the problem is exactly how you described it. as soon as i hit the slightest bump, the car steers eradically/violently to the left or right.

hope this helps,
and there is a very good possibility that i might be way, way off.
thanks again,
steve

 

Did you reset the toe - in after lowering? If the angle of the arms change any, then that's part of the problem...

You ask 10 different people what bumpsteer is, and you get 10 different answers, and solutions.. Somebody needs to write a book on " Front Suspensions 101" and it be required reading when you join the HAMB...

Brian

 

Yeah, bumpsteer can cause that condition in my experience. I would be weary of what I think you are saying with the long bolt to replace your outer tie rod to steering arm attaching point. If you are going to go that way, you will need to do it with spacers and not just the long bolt. It would, obviously not be strong enough to handle the loads. The spacers used in that configuration make me nervous, the bolt alone would be untenable. It would be better to reconfigure the steering arm itself. Is it a bolt on steering arm or is it cast nto the upright?

 

Wow that's a really cool lookin' car! Here's a picture that might help with aligning your tie rod.
http://server3.e2etech.com/~admin4/AdvHTML_Upload/bump_steer_drawing.jpg
I've seen this pic before and I used it when I lowered my car and made a couple other adjustments. You can see more if you Google image search "bump steer." You can also do a little searching and find ways to measure bump steer, which is something like measuring toe when it's on the ground and measuring toe again when you jack the car up.

 

As far as defining and explaining how to correct bump steer, I really like this diagram.



This really helps explain what causes and how to fix bump steer.

 

I was too slow, Bob beat me to it.

 

Thats a great looking Galaxie and lowered sits right. Take it right to an alignment shop and have them correct the front end alignment. Caster and camber does change when springs are modified. You might consider buying Eaton or Eibach lowering springs to get the correct stance and replace the stock ones you cut. The FOGGER

 

Bump steer is the change in toe in and or out, though the up and down travel of the wheel (vertical movement). It will most definitely cause a car to dart around. Spacing the tie rods with an offset bushing will correct a bump steer problem.

 

I'm pretty darn fast. I was once clocked at 670,616,629 mph.

 

Is there room to to relocate the whole tie rod arrangement higher in the car so it stays in the same location relative to the spindles? Bend the pitman & idler arms? If that is even the issue - as mentioned earlier, that sort of 'squirrelly' behaviour could be caused by other factors. Lowering extreme enough to cause this needs to be realigned by someone who knows their stuff.
Anti-dive, ackerman, roll cnters and other geometric considerations have been thrown out of whack, you need to know which one is causing this reaction before making any more mods.
But it does look good down there! Keep us posted!

 

I take too long too type, all the good answers popped up while I wasn't looking!

 

That explains it Bob, can't compete with that kinda velocity. Steve, If fyou were on the other coast I'd be happy to help, this is right up my alley. Anyway, lots of good advise here.

 

What if the A-arms are nearly parallel? That would place the I/C in that photo on outside of the opposite side of the car. How would you get the tie rod angle to intersect that?

the intersect points of the tie rod ends makes sense. But the "tie rod angle" doesn't.

 

You basically have 3 links with a double a-arm setup. One link is the upper a-arm, then the lower a-arm, and then the steering link which ends with your tie rod. You want all of them to share what's called an instant center. The instant center can be found by drawing perpendicular lines from the velocities of the points you're looking at. In this case, you'd draw a line from your upper ball joint, lower ball joint, and tie rod end. You know that the upper and lower a-arms are pivoting around a fixed joint, so you can draw your line in line from those links. For the tie rod, you'd draw your end through the 2 tie rod ends. I think next year is when I take a vehicle dynamics class (or that might be 2 years away). Anyway, the instant center is what the "rigid body" of the 3 links is rotating about at 1 instant in time, just a split second. When they don't share an instant center (which you'd measure at ride height since most other scenarios are hard to measure), things can change to the point of creating erratic and unpredictable behavior, in this case bump steer.

 

Oh, forgot to mention what you can do with that. Your instant center can be on the inside of your tire, near the center of the car, if you're talking about arms that are more like a Mustang-II setup (in some cases).

 

Wow I messed up. You're instant center will be near the middle of the car. If you end up with an instant center far from the middle of the car, it'll be a weird feeling going around turns. The instant center is what the vehicle is rotating about at that instant in time. If you get a Hot Wheels and put the bottom on your finger and rotate it side to side, then put it on your finger off-center, you'll see what I mean.

 

here's a better pictuer of a "bumpsteer kit". you can see the tapered part, that goes into the steering arm and replaces the tapered part on the tierod end. and with a stock tierod end, the bottom part of the tierod end would be right below the tapered part. with this kit, you can lower the heim joint, that replaces the bottom part of the outter tierod, to basically the bottom of the threads of the tapered piece.

thus, you get back some of your angle of the tierod, downwards from the center of the car to the steering arm.

yeah, it looks great sitting that low. but i can't drive it the way it is. but i didn't want a racecar looking car that didn't sit really low. in hindsight, it probably would have been tons easier to just lower it until the fender lips just cleared the tires. i lowered it so much i had to trim about 3 inches from the fender lips.

i don't have the stock springs in there any more. it rode a little rough, so i had a company build me a new set of front springs that kept the same ride height (i am not willing to sacrafice ride height). they didn't help much and certainly didn't help the bumpsteer issue.

yeah, i could change (lengthen and thusly lower) the steering arm itself. it is indeed bolted to the spindle. we did this in the 90's when we were circle track racing and had to use "stock" spindles. if this bumpsteer kit doesn't fix the problem, i think that is my next option.

and frankly, since the bumpsteer is so severe and lowering the steering arms down a couple of inches didn't seem to change anything, i think i'll have to do both. as in the bumpsteer kit and change (lengthen and lower) the steering arm..
thanks for all the great advice and help.
only here on the HAMB!
steve


http://images.marketplaceadvisor.ch...visor.channeladvisor.com/hi/77/76596/bs-d.jpg

 

here's another pic of a bumpsteer kit. the upper tapered part replaces the tapered part of the tierod and the heim replaces the lower part of the tierod that threads into the tierod adjuster. with this kit, you can lower the heim to reduce the bumpsteer, hopefully. and get back some of your "stock" tierod angle.

 

here's a better photo of the tapered parts.
thanks,
steve

 

hopefully i'll get all the parts by this weekend and let you know how it works.
(selfless bump).

 

i hope you guys know to use a large flat washer on both sides of the hiem joint.that ball will pull out under load.i had a good friend that found out the hard way....

 

I think some of the misunderstanding of the severity of your problem comes from the difference in front tires from traditional cars. If you slam a car with skinnies the problem is less noticeable due to tire geometry (the contact patch can squirm & be more consistent with skinnies). Plus when your tires wanna do something, they got plenty of grip to do it.

good luck

 

bava17, If you know any round track racers in your area, they normally keep a bump steer gauge in the shop. You'll have to raise the car on stands, remove the springs and set the suspension at ride height to check it. Neither side should bump out more than .030 @ 1". If it's more than that, you have found your problem.

 

hey linkin and shifty,
sooo......on the very bottom of the threaded part of the tapered rod, does it go in this order?

locking nut, large flat washer, heim joint, large flat washer, locking nut?

obviously, i guess, the locking nuts are to secure the heim to a certain spot on the threaded portion of the rod.

move the lock nuts up and down, and thusly, also move the washers and the heim up and down????

shifty, you maybe absolutely correct about the width of the tires. i never thought about that. they are definitely of the "extra wide" variety and grip alooooot. especially compared to the traditional rod style (skinny) prevalent here on the hamb.
thanks for your time help,
steve

 

keep in mind the flat washer will need to be large enough in diameter to aid in the prevention of that ball from pulling through,should it fail.
other than that,your onto something positive.

 

hey linkin,
if you have the time,
please go back to a previous post i wrote in this thread.
it's post #19.
go to the bottom of that post and see if you can click on that link and get that photo of Spohn Performance's bumpsteer kit.
notice the washers on top of and on bottom of the heim, between the lock nuts.
that is probably what i need?
would just regular, flat washers suffice?

thanks again,
steve

 

Many 50's and 60's Ford front ends had bump steer built in. Not on purpose, they just didn't do a good engineering job. In normal driving it wasn't a problem, but when severely lowered (or raised for a gasser) it became evident. Jack up an early Falcon or Mustang and watch how near the end of the travel the wheels toe change like crazy. About .250" at each end of the travel spectrum!
My guess is that your Galaxie suffers from this same malady and your lowering has put it into that range. Add the fatter wheels and tires with more offset and you have copunded it. You will need to use a bump steer gauge to get it resolved in your lowered state. You want to strive for no more than .030" within you normal travel at the new ride height.

 

yes,those washers or flat ones will save your ass.