front end bounce

[Crow Magnum]

hello out there..i am crow magnum and have been a hot rod muscle car harley guy for 100 years..boy am i old..i now have a 1969 1600cc v.w. dune buggy..manx style..full chassis. a bit unusual i am told..i am familiar with what we call the death wobble . usually caused by a bad steering dampner..so..now i have a tire bounce at just over 45 mph.. i have balanced tired ..rotated tires and have not changed a thing.i am noe told that old worn out shocks will also cause this..ALL AND ANY HELP would be apprecited..

[Bryan Porter]

Check tires,wheels,and adapters for roundness and they run true.
old shocks will let the tire bounce but some thing must get it started.
Some for the guys on here don't run shocks at all.
Where do you live?

[GregR]

As Bryan said, check wheels, tires, adapters for trueness.
It sounds like maybe a slightly bent rim.
I think it's unlikely that it's a worn out shock issue as a number of guys run no front shock on their buggies.
Do you run between 14 and 20psi in the front tires? I assume it's just a front end issue for you.
Don't run over 20 or it'll ride like a rock.

Anybody near you that you could swap wheels with for a test?

[68buggy]

now i have a tire bounce at just over 45 mph.. i have balanced tired ..rotated tires and have not changed a thing.i am noe told that old worn out shocks will also cause this..ALL AND ANY HELP would be apprecited..

Well since you said you balanced AND rotated the tires and no change we can assume its not a tire issue ( although you can balance a tire that is out of round) the fact that you rotated the tires and there was no change means its not the tires or wheels.

When this vibration starts at 45mph I am assuming you are on a flat road so that means its not a suspension item. With that said you have eliminated tires and shocks.

At this point I recommened you jack up the front of the car and check for play you may have a front torsion issue.

The only other thing I can think of is maybe you have a drive train issue I have seen cv axles cause simillar vibrations but only under acceleration.

Does the problem persist if you push in the clutch and coast?

If you are in the houston area you can bring it by the Gillman Subaru South I work in service and can check it out for ya (for free that is)

Good luck,
Shawn

[Crow Magnum]

hey guys thanx for the input..shawn what kind of torsion problem might you be meaning..also what about the steering dampner..it looks newish,.

[68buggy]

The dampner is mainly there for bump steering and to slow your steering so you dont over steer at high speed is my understanding. But just unhook the dampner from the tierod and push it in then pull it out if it has resistance like a good shock does then its good.

What I was suggesting is that you may have play in the front end and when you get up to 45 plus the front end starts to shake. Specificly the torrsion tubes have bearings and bushings where the trailing arms go in a little bit of play in these bearings and bushings means alot of play at the arm were the ball joint is.

If you pick up the front of the car and shake the tire around and it is tight then your good on that.

Did you try to drive it and see if the vibration goes away when you push in the clutch?

Alos do you feel the vibration only in the steering wheel or do you feel it in your seat?

[Ken]

Hi Crow, welcome to the Texas Manx Club forum.

When I hear tire rotation, on a typical buggy, I assume its just side swap, not a front to back, etc...?
If so, this would not rule out a tire or wheel issue.
You didn't say if you are using adapters? Balanced tires, doesn't mean balanced adapters.

GregR had a simple test suggestion, if you have someone near enough.
Find an alternate set of front tires to temporarily install, see if it goes away.
At minimum you rule out tires and wheel.
Where are you located? What lug pattern do you have?
Many on this forum would be welling to help you out.

We always appreciate a picture or two of a new car?

[Crow Magnum]

alrighty then..i am looking to find some vw wheels to pass by the adapters..they are 5 lug chevy to stock 4 bolt drums..however they are 3/4 inch only and each bolt has a shoulder like it should have no variences like a conical spacer would have..so....new shocks and new brakes and it is 70 percent better..actually masks it pretty good..it is still there at the same speeds but not shaking to death....i tryed differant tire pressure and no differance..i feel the unbalance at low speed also..wonder if my toe in is messed up is the tire pushing and causing it to jump at speed with such a light front end..going to get that done next..i cannot be the only person with this experience....

[staggerwing]

Dude - I had a vibration problem for a very long time. I had my wheels balanced twice previously, so that couldn't have been the problem, right? Wrong. I was the victim of a poor balancing job and it drove me crazy till I took a suspected wheel in for a "rebalance". They removed all the weights and balanced the wheel. Problem solved. Yours certainly could be something else but if you have a vibration, I would suspect balance first, adapters second. Adapters are a whole nuther story too. These cars are (or can be) very sensitive to road condition depending on your set up; mine is. I have a really stiff front suspension and it takes very little "road noise" to make her shake. Now that the vibration is gone, I'll be working on a softer ride. Just fyi...