WOBBLY-T

[2old2fast]

Don't know if this is true or not but a retired machinist told me that if you have the diameter of the bolt [1/2 "=1/2" in the threads] ,that maximum thread tensile strength was achieved. That being said, I hope someone else will weigh in !! personally,I'd leave your caster alone for now and experiment w/ toe settings, wheel balance, different tension on your friction shocks first .Are you running a heavy wheel /tire combo ? is your front brake package heavy ? Keep in mind that all that unsprung weight is a long way from your shock mounts i.e. requires more precise control [keep in mind that under normal road conitions the axle is only going up AND down about an inch total ] I switched to hydraulic shocks, still did not have contol [better but not great] that's when I found my tires were out of round, [an alert young man who was balancing my tires for the thid time] swapped the tires out , it was like a new car !!!!



dave O.K. like john, now my 1 finger hurts!!

 

[jackfordt]

Neat answer will try some experiment. I have a 37'ford axle s-10 calipers with heavy backplates with steel wheels and fenders mounted on (probably heavy) tires are coker brand new except for the 500 miles i done on them. If i put too much torque on my friction shocks is it affecting something............... Thanks

Don't know if this is true or not but a retired machinist told me that if you have the diameter of the bolt [1/2 "=1/2" in the threads] ,that maximum thread tensile strength was achieved. That being said, I hope someone else will weigh in !! personally,I'd leave your caster alone for now and experiment w/ toe settings, wheel balance, different tension on your friction shocks first .Are you running a heavy wheel /tire combo ? is your front brake package heavy ? Keep in mind that all that unsprung weight is a long way from your shock mounts i.e. requires more precise control [keep in mind that under normal road conitions the axle is only going up AND down about an inch total ] I switched to hydraulic shocks, still did not have contol [better but not great] that's when I found my tires were out of round, [an alert young man who was balancing my tires for the thid time] swapped the tires out , it was like a new car !!!!



dave O.K. like john, now my 1 finger hurts!!

 

[Gerry]

Don't know if this is true or not but a retired machinist told me that if you have the diameter of the bolt [1/2 "=1/2" in the threads] ,that maximum thread tensile strength was achieved. That being said, I hope someone else will weigh in !! personally,I'd leave your caster alone for now and experiment w/ toe settings, wheel balance, different tension on your friction shocks first .Are you running a heavy wheel /tire combo ? is your front brake package heavy ? Keep in mind that all that unsprung weight is a long way from your shock mounts i.e. requires more precise control [keep in mind that under normal road conitions the axle is only going up AND down about an inch total ] I switched to hydraulic shocks, still did not have contol [better but not great] that's when I found my tires were out of round, [an alert young man who was balancing my tires for the thid time] swapped the tires out , it was like a new car !!!!



dave O.K. like john, now my 1 finger hurts!!

I was taught the the max strength of the engagement of a thread was the minimum diameter of the thread. That is at the root of the thread.
If you think about it the bolt or thread can only be as strong as the root diameter because thats the 'weakest (smallest) part. Now other things come in to this such as side loadings etc Personally I like to see twice the root as a minimum engagement.
So I agree with your retired machinist.

 

[VegasBruce]

Hello, i am new here just finished my T last year with Total Performance plans ,using a '37 ford front axle with friction shocks with a 34" trailer leaf spring. Everything goes good before 50 aflte wabble comes in right and left tire starting bouncing . Any suggestions. Thanks Jack

But Bruce as he said it's a right left wheel BOUNCE not a wobble.

Sorry Rick, but I read that it starts wobbling at 50 and then bouncing. That sound exactly like mine was doing. I reset the caster and toe, put a little tension on the friction shocks and she handles great. A little time on a near level floor with a protractor and tape measure will make sure the alignment is spot on. If its not now, fixing it will make a world of difference. But yes it could be shocks, out of round tires or balance also.


JACK, I don't think 4 degrees of caster is enough, but there is no magic number. Its a trial and error thing.

 

[ellis8500]

Suspension bounce is an indication that the spring is oscillating at it's natural frequency. Shock absorbers are meant to prevent this from happening. What usually starts this off is a small bump coupled with a bit of unbalance in the rotating parts; i.e., wheel, tire, brake drum/rotor. If the conditions are right and the spring is not sufficiently dampened, oscillation can occurr and your wheel will bounce up and down until you eliminate the condition. Slowing down, speeding up, more dampening [hard to do while driving]. So try tightening your friction shocks. Try a different material than what you now have. Convert to hyd shocks. Verify wheel balance.

 

[oldser]

Hi guys. My name is Dick, I'm in Tampa, from Detroit originally. My T is totally home-brewed, including frame and bracketry, and, like everyrthing I've ever done, it LOOKS like something I did! (That's a confession, not a brag).
I built it in 1967, had tons of grins in it.
I fought the death wobble too, still not back on the road. I had originally used an inverted Corvair box mounted under my feet (I wanted the old-timey look of the vertical steering). Car drove just fine for many years and man y, many miles. The wobble hit me at 55 all of a sudden one night and I fought it for years (different shock setup, steering damper, a dozen alignments, etc. It was random and unpredictable, except I began to notice that sometimes I could feel a very slight vibration, like a buzz, in the feel of the car. That seemed to be when it would happen. Otherwise, I could go hundreds of miles with no problem. Could not find the cause, so I decided to switch to Vega cross steer. The old setup had a ton of flex in it due to the mounting of the Corvair box and the long drag link.
The front axle was an old dago style dropped and chromed I-beam with 48 Ford drums, which I switched for Super Bell discs. A little better, still not fixed.
During this latest tear-down I took the axle apart and found the right side spring mount hole had 'woggled' out oblong. I scrapped the axle and got a new Super Bell. I'm guessing (hoping) the explanation is that accelerating and braking would cause the axle to shift in that hole, causing the random vibration.
I'm still torn down, so don't know if that fixed it, just thought I'd share my misery with the group.

 

[Ted Brown]

Wheel wobble can drive you nuts! some get it after years of driving with not problem, that tells me something is worn out or loose, not caster or some other setting, other than Toe in settings, as that can change with worn or bent parts... or like you say, worn out shocks