Death wobble truble???

[chopper tom]

I have just been working too hard on it lattetly [ i seem to for get it's suppose to be a fun hobby ,i always work too hard on my projects and get burned out on them ]
I thought i had it fixed when last time i drove it ,it drove great[except for the carb,its junk] And i was way excited. butttttt,,,,,
when i went to drive it yesterday ,i found that the front drivers tire only had about 10psi in it and i know it must have been that way when i last drove it[i have had a slow leak on my big fancy ''junky''valvestems that i payed like 5 buckes for ,to heck with that ,i'm going back to my cheep rubber ones soon as i can,should had known better?]
So when i checked and corrected my tires pressures , i took it out for a spin and ''wowy o' wow'' its doing it again .but i found that the cotter pins [inthe 50 chevy ty rod ends was not there[i forgot them ]and was backed off alot!:surprised: So 'bingo'! i thought that had to be it,so i fixed it at break neck speed and hurryed out to try er out ,but to my dismay it had no change to the bounce.
I came home and looked in to my papaw's old Motor manual,from 1932 to 52.and it says to set the tow at 1/8 and the caster at +1/2 [wierd ,iknow but i'll try it !]

So thats were i am at ,on my next day off i'll try the caster and see what happens?
Thank all you guys for the support and info ,sure has helped!!!!

Nope ,RPM i still havent had time to check my drive shaft ,i just cant seem to get the stuff done that i want to do in a day off work,it would be nice to be in my 20's again i could have built two of these by now?!

 

[oldser]

C.T.:

My car had an older chrome I Beam axle, a Posie's slide spring and steering was an inverted Corvair box directly under my feet. Because of the design of the X member, I could only weld the box mounting plate on two sides, so the box could flex forward and back when I steered. Then, I had a long drag link up to the left spindle. All of this contributed to a lot of flex in the chain. But, I drove the car for 10 years local and to out-of state runs with no problem at all.
One night, coming home at about 55, I got the wobble. Bad. When I finally got stopped, the tie rod was bent into a V and the tires splayed out badly.
I tried a steering damper, hydraulic shocks, fooled with alignment, etc. No help.
The wobble was VERY intermittent, happening only once in a great while. But I did notice there were times the car was smooth as silk, but sometimes I felt a little buzz in the chassis and that's when it would happen, if at all. I was totally stumped.
Last year I tore it down to switch to a Vega cross-steer and in the process I found the right spring mount bolt hole was 'woggled out' (elongated). I hope that explains it, because it makes sense regarding the come-and-go. The spring mount was able to shift back and forth with braking and accelerating, maybe causing the problem.
I say maybe because I have a new axle but the car is still apart.So, I don't have a solution, just another thing to look at.
Thanks for reading this dissertation with no conclusion !

 

[chopper tom]

I have about narrowed it down to the tires [there bran new hoosier 25/7.50/r15]
the drivers side ,i think is most likely ''out of round'' ?the reasone why i think this is that it has a slow leak from the valve stem and i some times forget to check the tire pressure when i take off and when i do it doesnt give me any problems[but the tire is like at 10psi or so]Its really weird and i havent took the time to jack it up and put a dial indacator on it to see if it actually is out? Will report back as soon as i can .
Does anyone know the run out for a tire?????
I got to say that it's weird that i can drive on a almost completly flate tire and can tell very little differance on how it drives,just a little drag when i turn ?All i can figure is where it doesnt weigh much,but is good to know that if i have a flate that i can still drive home ! T -buckets are so cool!!!!

 

[TheAntiBoyd]

I think you really need to take a scientific approach here. Too many variables. You need a systematic approach to what youre doing instead of throwing random numbers at it. These cars all all different so going .125" in or out on one car is different from another. You need to leave everything AS is and change one thing, just 1 thing, at a time in a list, then bump one variable up one notch and run through the cycle again.

Although, I would check all your nuts and bolts and make sure you dont have something loose. Id also check your driveshaft and install a loop if you dont have one.

What front brakes do you have?

What front rims do you have?


Some people have trouble with the GM intermediate brakes causing some buffeting with their large envelope. Also, you may have a bent rim.

What do you tighten your lugnuts to? On my dads old ansen 5-slot Uni-lugs, when you take a wheel off and put it back on, you have to snug them down...drive the car and re-tighten them or else they wobble like crazy and will eventually lose a lugnut.
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Im reminded why I dont want friction shocks or bias-plies...they were never intended for 70mph lane changes in a panic. If some traditional pest wants to point out that I dont have square tires on my ride...fine, I'll remind him that my car doesn't have his name on it either.

 

[Wild Mango]

Something potentially disastrous going on here when it bends a tie rod.

I agree with the AntiBoyd, time to be very careful with the engineering. At the risk of sounding melodramatic, these things can kill you. So many variables at work.

One thing I mentioned on another thread hoping to get some feedback. These cars are light and in my experience (&IMHO) most people tend to over inflate the tyres - you mentioned it yourself when you said its hard to "feel" a 10 psi tyre. It could be that 10psi is about right. My last bucket liked 11psi on the front 14" radials, any more and the front end rode hard and bouncy. With a light sprung mass the shocks don't have much to work against to damp the unsprung weight, which is a much higher percentage than usual automotive applications - if the tyres are hard and bouncey like a basketball they are a lot harder for the shocks to control.