Death Wobble - speedway tie rod may be suspect

Dave, I never drove it until Saturday, so all three things were done at one time.

 

Well I'm glad to hear that you are back on the road and feeling confident in your car. I think I fixed my issues as well. I was having the same problems you were, with the crappy tie rod and a myriad of other ailments it turns out. I wobbled so bad that it bent my tie rod and drag link and radius rods. I had a a shop build me new tie rod and drag link out of solid 3/4" rod that is used in hydraulic cylinders, and replaced the radius rod. I then began to go through the front end again, and found that I had no shims in my kingpins. I am finding more of this "shortcut" type of building on my car. No I didn't build it. I guess if you build the car only to show then this would probably be sufficient, but a little heads up when you sell it would be appreciated. So I checked everything again; toe in 3/16"...check; caster 7*...check; camber 3*...check; tight steering box...check; SQUARE FRAME...double check; SHIMMED THE DAMN KINGPINS...CHECK; double checked the kingpin retaining screws ( I have an MAS drop tube axle with the set screws). I took it for a drive and it seems to run just fine. Still no shocks, but I have a set of friction shocks on the way. I saw a set of early model MG hydraulic shocks that look pretty slick, I might find a set of those over this winter. Still a little nervous over 60 mph but I think I'll feel better after the shocks go on. By the way I could flex my tie rod too.
Well enough of this essay, I'm back on the road and happy about it!

 

glad you fixed the death wobble, now you just have to deal with the Oh shit blower induced traction problems.

 

seem s more like spacing the spring took some of the caster out.

 

Well, all i can say is i hope i dont have to deal with this shit when my A gets on the road..what a PITA!

 

Sorry but I join the cast of doubters on that tie rod bending stuff. The tie rods are 7/8' x .156 wall if you have a 5/8" heim end. If you have 11/16" tie rod ends you have a 7/8' x .120 wall tube. If you are bowing this by hand, Sign up for WWE or Tap out. You are correct in assumption that by doing three things at once it is hard to isolate the problem but what stands out is that you put spacers in to raise the spring/frame height. By raising the chassis height you have removed a slight portion of caster gain upon bump, less caster less chance of caster wobble. In addition if you re set the toe and re adjusted the front end you may have realigned something that was misaligned at the start so if you are back together and running straight thats fine but get rid of that POS welded on angle iron tie rod. One other thing if you have wider that stock tires that 3/16 inch toe will start to show a feather edge of excessive toe in on the tire tread and cut down its mileage life. I'll bet a new tie rod double or nothing that its not the tie rod.

Note to Rat: 3 degrees camber is like running on the edge of the tire is that correct???

 

Check toe in , The axle should have a 8 degree angle backwards

 

I didnt read all 150 comments but the title.
I have speedway's tie rod and drag link, they work perfect for me. No issues.

 

This is an example of why catologs kill!!!!!!!!!!! most if not all is junk nowadays, it;s made to go to the store and a weekend show and get put up. I was showed this a few years ago when I was helping an old man build cars and he asked me if the sterring arm was strong enough( I guess he suspected it was'nt) and jump on it and bend it was, just because it comes in the mail does'nt mean it's good,, they don't have to sit across the table from YOUR family at the dinner table so they don't care, JUNK (sorry for the venting)

 

Not sure exactly what you said there Mr. Cracker.

But, if people are buying the stuff from the aftermarket and there doesn't seem to be a problem with it if it's installed correctly where else would you get it?

Some of us can make some parts, but if not for the aftermarket the majority of us would be walking.

No aftermarket parts in your car?

 

I did not raise the spring with spacers. I put a spacer under the bottom of the spring so the piece that clamps it would clear the bottom of the cross member. I think the u bolts were pulling the clamp up far enough to interfere with the bottom of the cross member on the front side SLIGHTLY in one little spot. SO it tightened down on the spring and then slightly touched the cross member when it was all torqued down. I re-read what I wrote and where I put the spacer wasn't that clear from what I stated.

I'll say it for the 10th time. I could bow the tie rod by pulling on the tires with light pressure. I think it's hilarious people think I am stupid and can not relate what I see or that I am lying about it. Not only that, a friend of mine with the exact same set up can do the same thing with his car. WTF. over.

I do plan on cutting the anlge off and sleeving my existing tie rod.

Went for another great ride tonight and it was fine.

Wow - thanks ya'll

 

Josh.......You're so Dreamy...................and strong!!!!!

 

:d ignore!

 

I learned at least 5 new "things" just reading this whole thread!

 

I just went through my car a few weeks back because I thought I had the death wobble. the car shook at slow speed and at high speed. It all came from the rear tires being very unbalanced (7 to 8 ounces per wheel). With that taken care of, the car ran prety nice. next I through away the Speedway rod ends, they were junk when they were new. I had some good rod ends from some of the race cars I have worked on, high doller ones too. There was a ton off slop before I changed them and now it's perfect, no slop at all. I also stung the car to do an alighnment. Running some string from two jack stands at each end of the car. I ran this parralel to the chassis and adjusted the toe (1/8 in). This is best the car has driven since new. Buy good rod ends and get rid of the slop, just because it is a hot rod dose not mean it has to drive like a tractor.

 

I tried to read it all, but kept falling asleep.

Glad I didn't put in my 2 cents worth in, people call me stupid enough.

Just glad it's fixed.

 

Oh great a new twist to the story, why don't you post a picture of this so called tie rod bow and prove us all wrong, I'll still bet you a tie rod that thats not the problem. Ok if you didnt put the spacer on the top of the spring and put it on the bottom that would indicate to me that the spring wasn't pinched tightly in the front cross member on the first go round or you took out to many leafs to get the car lower so the ubolts only tightened up when the cross links bottomed out on the cross member. If the center bolt was loosely positioned it will cause the front end to wander. The addition of the shim severed to correctly nest the front spring and properly located the spring center bolt.Glad your car is now drivable.

 

You, my friend, are the man!! Great job!

I knew you would get it.



BloodyKnuckles

 

I totally understand your problem and I am sure there is alot of good info in this thread. But here is what I have found.
I have a traditional with buggy spring, bias plies, 32 box with Terraplane guts and an uncut wishbone with an unboxed 32 frame. It will GPS at 122 mph with bias plys and it is rock steady no matter the terrain and I've had it on a dry lake doing that with no steering dampner.
I don't car if your tires are out of balance or the alignment is out of wack or its tracking down the road sideways. If you have zero and I mean zero tolerance in the front end, that means honing the king pin bushing not reaming them. A properly adjusted box that has very little sector shaft backlash, I can't go more then about 2.5-degrees of sector movement or my shimmy comes back but it does still feel safe with the big tie rod because I know it isn't going to break on me. My tie rod is 1 1/4 moly and I can still flex it a little by pushing on the tires so I know where your coming from on that. I changed mine because it was an original split tubing Ford unit and when it got the wobbles the car was really unsafe; the tires would literally hit the headlight buckets with the wheels pointing straight ahead no bs! my friends with hot rods crapped when they saw the marks from the tires hitting the buckets.
So here is the reasoning. To get a wobble you must have free play. If you eliminate all the free play you can't get wobbles.
Think of a 4X4 with a straight axle. Big tires and worn out front ends but they don't get wobbles, most have worn out shocks, springs and shackles but unless the wheel bearing are falling apart they still don't wheel wobble; right? because a modern steering box compensates, wheel bearing technology is advanced and the tie rod doesn't flex.
You need to look at your drag link too but that doesn't have nearly as much effect. I find it is more noticable in the understeer due to the initial flex before the wheels actually begin turning. Lastly since we where talking about wheel bearings you can't have play here either, that's a big one! I don't know what you have for spindles and nuts but you must find a way to get them tight enough where they will have no play the bearing preload is critical.
If you look at some old hot rod mags you will find a patented invention that featured micro-adjustable spindle nuts to cure front end wobbles.
I had a set on a 427 Mercury I bought and that is the only set I've ever seen but they allowed precise adjustment of the bearing preload. My remedy is to use the modern stamped steel cotter pin retainer sleeve with a regular spindle nut instead of a castleated nut. This was the OEM's way of avoiding the patent, they did it cheaper but it isn't better, it does work well though.
And finally I had my wheel bearings and races ceramic coated so they would hold a pre-load correctly.
It took all of this for my roadster, because I was hell bent on not using a dampener or cross steer. I still check it every few hundred miles because things just wear on a true traditional and about every five hundred or so miles I have to adjust things slightly. I know it seems like alot of work but if you look at an old service manual that's what they did.
I just thought about old Indy cars; they were out there buzzing around at over 100 with crappy tires, lever action shocks and leaf springs with shackles on a brick oval with no steering dampeners and the old timers say they didn't get wobbles unless something was wrong. I went to quite a few of them for help and they did give me a lot of insight on the old front ends and handling at high speeds.
One more little thing; lots of very knowledge people will send you down the bump steer road and then suggest a dampener. I looked at bunches of pics of old Indy roadsters and very few if any have the suggested drag link angles many builders push on us today for the suppossed correct bump steer, same guys telling you to have a dampener installed, when its right you will not need a dampener and it won't wobble it just takes maintenance and an understanding of what your looking at.
Good luck and the offer still stands if you need help over the phone.

 

This from a man who can actually supply you a tie rod, and has been dealing with this stuff for about a million years. way to go Dick!

 

This years death wobble thread seems to have more technical info compared to last years two wobble threads.
Lots of opinions that a damper masks the real problem and there has never been a definate answer as to what the root problem is. "777"'s detailed and well written post about setting the entire front end up with aircraft precision and doing so each 500 miles sounds to me like the root problem is really still there, but that intense maintainance keeps it from doing the initial convulsion that starts the wobble? Is that masking also?
Dick's posts this year seem more refined than his posts last year. I have never heard about the 4 to 7 camber, let alone,setting it more towards the lesser amount. As a long time modern car mechanic, the 7-8 degree never made sense to me. Also his info about "the spindle is a toe-in type, when turned". If I read that right, that is opposite of what somewhat newer cars do? (like 60s and 70s) Those newer cars had toe-out on turning. So, I assume that if a major caster change is made, would that also affect the amount of toe-change on the start of a turn...just like the "start" of a wobble? I start to wonder if it is a balance between the exact caster setting and the design of that toe-in-at-turn type spindle? I realize the theoretical tire/road contact patch on a 7 degree kingpin is way forward of the "lowest" spot on the tire. I think this is all related to the start of the convulsions??
I have no engineering backround, but keep thinking that hamb threads will figure this all out someday.

 

Back to see what has transpired, This post should probably morph into one of its own but with a bunch of people following no use to start over. Tudor started the post on a tie rod issue, that is pretty much resolved so this is a good way to continue with continuity on the subject.

777 you are correct on eliminating any excessive clearance in your spindle bearings, king pins , tie rod ends and steering box. However your statement regarding neglecting alignment or tire balance is not correct, you are going to have a problem and you even admit that you can only turn your box 2.5 degrees before you have a vibration, at a couple of degrees swing you should be beginning to institute a turn, so that indicates to me that although you have every thing snugged up there is still an issue and at 122 you were holding on pretty tightly. You must know the position of your tires on the ground and their relationship to each other if you want to solve handling issues.

Caster wobble has always been a problem with i-beam axle cars and the only reason that they are still used on larger vehicles is the large vehicle mass masks some of the faults that are displayed with lighter vehicles. Most people have been trained on principles of IFS suspensions and some of the theory is interchangeable and some is not. We are dealing with ox cart technology not F1 Ferrari.


F&J I don't remember discussing excess camber of 4-7 degrees but 4-7 degrees caster is the norm for I beams I favor lesser number settings, the car steers easier and there is less chance of caster shimmy. The Ford spindles and all the Hot Rod spindles are 1 degree positive camber for an I beam, meaning the top of the tire points outward from the vehicle center line. This necessitates a toe in tire setting for correct tracking. Don't be confused with newer IFS cars that run slightly negative camber and require a toe out when setting the front alignment specs. All I beams run slight toe out during turns based upon the ackerman setting of the steering arms. If you have bent, shortened or modified your steering arms for clearance this is where things get screwed up also and that is a whole new subject.

Now on that POS steering dampener. One of the ways to reduce shimmy in an I- beam suspension is to have some degree of axial resistance. The easiest place to do this is with the king pin bushings. If you have a slight degree of resistance in the king pin bushings is helps control the tendency for the castered spindle to vibrate. So if you have worn or incorrectly bushed spindles they do not exhibit a sufficient resistance to prevent this axial movement. Thus it is important to have correctly bushed spindles and lubricated so they do not run dry and wear excessively. This is similar to info on a previous post relating to spindle drag. What that dampener creates is an external resistance to overcome worn out parts or some incorrect alignment. In other words its a band-aid to cover something up.

 

Before you sleeve your tie rod you should run it again with-out the reinforcement to see if that was the problem or if something else was...

 

Gotta get back to work....
Thoughts on the "inverted Y" style of steering linkage that is used on many 4x4's with a solid axle?
I've heard it helps prevent this type of wobble.

 

I'd post a pic if I could, the rod is now stiffened and everything is back together and hidden by the radiator shell. I suppose I could shoot it from underneath, but it doesn't flex enough anymore to be visible enough to get a picture of. Send me one of your tie rods and I'll try it out. I took your advice and will training kids for Tap Out. Are you coming to Charlotte in Sept? We'll bolt yours on and see.

From this thread, plenty of others have experienced the exact same flimsy tie rod phenomenon. I feel everyone's account of the situation is sufficient evidence that it is possible. I am sorry some people can't comprehend it.
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Have you ever actually known someone to take springs out of a spring pack and install it loose in the cross member with the clamp tightened merely against the cross member and not the spring?
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I didn't take any springs out of the spring pack, I did take the two shortest top springs and move them to the bottom of the pack to maintain the original spring pack height. The spring was clamped down. With the spring clamp tightened it appeared to SLIGHTLY interfere with the bottom of the cross member in the front center. It may not have even been touching. There were gaps out by the u bolts at ll four corners. It was completely clear in the back of the cross member, again with the ubolts tightened down.<o></o>
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My Experienced hot rod buddy just recommended I try a spacer to make sure the full clamping force. He told me to check the spring to make sure it was clamped since He had seen the wobble be caused by a loose spring pack which sounds like your experience as well. It was easy to do so I threw in a spacer.

I clarify this becuase it sounds like you had interpreted that clamp was tightened up against the cross member and the spring pack was completely loose. Not so. I had also previsouly plumb bobbed the king pin locations and rear end to check for square. It was all square.

 

What clamp plate/ubolt kit are you using? All the aftermarket ones I've seen (including ours) are supplied with a 1/4" or so thick spacer. If I go out to my '32 now, there's probably 3/16" between the clamp plate and the lower lip of the crossmember.

Just an aside - if the ubolt nuts aren't tightened evenly, it can cause a visual balance issue when looking at the front of the car.

Can I ask again what shocks you're using?

 

F&J said "I realize the theoretical tire/road contact patch on a 7 degree kingpin is way forward of the "lowest" spot on the tire."

Don't know if F&J is referring to scrub radius but I think not enough attention has been paid to that aspect....

 

QUOTE "
I didn't take any springs out of the spring pack, I did take the two shortest top springs and move them to the bottom of the pack to maintain the original spring pack height. The spring was clamped down. With the spring clamp tightened it appeared to SLIGHTLY interfere with the bottom of the cross member in the front center. It may not have even been touching. There were gaps out by the u bolts at ll four corners. It was completely clear in the back of the cross member, again with the ubolts tightened down.<O></O>
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My Experienced hot rod buddy just recommended I try a spacer to make sure the full clamping force. He told me to check the spring to make sure it was clamped since He had seen the wobble be caused by a loose spring pack which sounds like your experience as well. It was easy to do so I threw in a spacer. "

The after market spring I got for my current build (another A coupe) barely filled the front crossmember (which is probably normal) - I put the spacer (included with the speedway clamp set) under the spring pack to be sure of a tight fit, like you did. Like you, without the spacer under the spring the clamps seemed to slightly interfere with the crossmember and almost barely tighten up... Wonder how many don't notice this?

 

Hi Tudor, I will be in Charlotte for Goodguys in October. If you are there stop by. I stand by my belief that if you have enough force to bend a tie rod you have something wrong.

Changing the spring and not tightening the pack? All the time. Everybodys got there own idea on what looks good. The spring must fully align with the center bolt hole and lock down when compressed by the ubolt pinch plate before the plate or cross bars come in contact with the cross member. Just because the U bolt nuts are tight doesn't make the spring tight. The next issue is with replacement or retro fitted cross members being positioned off square to the frame or offset laterally to throw off the vehicle square. You'd be surprised on how many people cant read a ruler or never check square before hitting the welder, close enough is good enough.

To use you as example , you say that you plumb bobbed the front and rear axle and they where square to each other doesn't mean that the car tracked square. It only means that the axles were parallel to each other, you also have to square the front hubs to the axle because they can be adjusted off track for the correct toe and not be square to the chassis center line. The same can be said for measuring the wheel base, you can measure equal numbers on wheel base whether it is a rectangle or a parallelogram. Just measuring the wheel base does not give you a relationship between the axles and chassis center line position. It doesn't matter if you built or bought a car, it is important to know the foot print that your car makes as it rolls down the road and knowing this foot print helps determine potential problems.

 

Dick, It isn't enough force to bend the tie rod - it just bows and then straightens back out when you release the pressure. I agree something is wrong if you acutally bend the tie rod. But, what else could be wrong? There is an axle, there are two wheels attached to a tie rod. New heims, everything else is tight. No slop in anything. King pins are new. It's all good.

Who said I just measured the wheel base? I also measured the diagonal distance between the opposite corners to be the same. Wouldn't that indicate it is a square?

How exactly do you square the spindles with the axle? What surface on the axle do you check to be squrae with? How come the relationship of the two king pins and the outside face of the rims isn't sufficient if your front axle is square with your rear axle as confirmed by measuring equal distances from corner to corner?