Ok guys !!! I just got back from the dragstrip !!! Had to run 1/8 mile that sucked ! But anyways ,my HA/GR car has a bad side to side front wheel hop at about 70mph. or at the 1/8 mile mark !!! Anyone else have this trouble ? I dropped the air pressure to 20lbs. I have 10 degrees of caster ,and about 1/16" toe in !!! What am I missing ?
Volkswagon steering damper, because of the nature of the long steering arm, it might bounce a little and start this. Joe
We had a similar problem with hubs I redrilled. Once I put the correct wheels back on the bounce went away. Check your tire runout and balance.
I'm not sure what you mean. "Side to side" suggests a speed wobble but "hop" suggests a tramp (and the seventy mile mark also lends credence to tramping). A speed wobble can be from one unbalanced tire and/or from "springiness" in the steering mechanism/linkages. A tramp is usually due to imbalance and/or run-out. We had a front wheel tramping problem as well. I'd static balanced'em but even the slight run-out we had was enough to do that at just around 70. It went away by 80 when the dynamic overcame it. We were running'em hard for lower rolling resistance. Mollified it some with a pressure drop just as you did. Later we had the wheels spin balanced for 100 (had to mount'em to my own hubs and locate a spin balancer with large enough cones for the A-bone hubs) and that corrected it. Hope yours is as easy a fix.
this sounds like what a friend went through on his roadster. At speeds above the posted limit, one tire would bounce, come down, the other would go up, etc. like two overinflated basketballs on a see-saw. Reduced tire presure and tube shocks were the eventual cure. The friction shocks didn't provide enough damping, and required constant tightening.
That is it exactly ! Two basketballs with a broom stick between them ! I'm going to have the tires re-balanced , maybe my tubes have spun around inside the tire and got them back out of balance , I lost a valve stem after they were balanced the first time ? Thanks guys !!!!
Balance the wheels. That is a lot of Caster. The VW damper works well. used it in the 70s on a 6 Cyl altered with a Anglia front axle. Don
Got it, alternating wheel hop. Usually initiated by a balance and/or run-out problem on one wheel and can be exacerbated by too much toe in. Rarely (but not unheard of) a result of an out of true tire mounting or a bent rim, though these typically produce a wobble. You're likely on the right track with the balance.
Car runs good down the track ,nice and straight . Taking the fronts to the shop tommorow to have them re balanced !!! I have yet to make a full blast pass !!!!! And I sure can't wait
Had the same problem with my fed. Rebalanced the front wheels and added the steering damper. Fixed all the problems. Straight and as smooth as a arrow now. At 120 it was a scarey hand full.
did it to me once at 100mph, I called it he death dance. Got rid of the friction shocks put on good hydrolic shocks as upright as possible. Never happened again.
The Famous "Death Wobble"! many articles have been written about it. Firstly, all steering components need to be correct. If you are running a Cross-Leaf spring use a panhard bar because the axle wobble goes through the shackles [ "shackle wobble" ] Check to see if the wheels are actually round and straight. Too much caster on a beam axle is also a problem, if one side hits a bump it alters the camber of the other side [ the caster tries to correct this camber by steering towards the centre ] With front ends you need "toe-in with positive camber" or "toe-out with negative camber" [ this is to correct the camber thrust caused by wheels trying to travel in a "cone" direction against each other ] I once corrected a "death wobble" on a 4WD that had an out-of-round tire on the rear "it was loading the caster of the wheel diagonal opposite" [ to understand this, Jack up the RR and the LF will try and steer right ]
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