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"Death Wobble" in '67 a-body - think it is FIXED! #2491150
05/02/18 10:38 PM
05/02/18 10:38 PM
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Cincinnati, OH
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6T6Cuda Offline OP
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I have a completely rebuilt '67 barracuda. Ever since I put it together it always had an odd shimmy in the front end. It was never that bad, just something that I could never figure out. It would come and go randomly.

The car is "completely new", full rotisserie restoration, almost every part touched.

Setup:
1. manual steering, I installed and setup myself the 20:1 quick ratio gear box.
2. All new Moog (US) front end components
3. '73 (used, but restored) front disk brakes (and the 10.5" rear drums for big bolt pattern on the back).
4. Alignment done by me with a fasttracks unit. Aligned for maximum caster, I can't remember where I set the camber (1 deg?), and the toe at 1/16 (I think).
5. new rubber LCA bushing, Moog Rubber "problem solver" rubber bushings in the UCA (2x in each in opposing directions)

Car drives straight, but does have a lot of slop in the steering wheel (at least from 11 o'clock to 1 o'clock). Overall it handles well.

Sometimes if feels like the front end is moving to the right and left a little bit in some set frequency, moving faster you can "push through it" and then it stabilizes out.

I drove the car today, and it appeared a little worse, but it has been a while from the last time I drove it, so I don't know.

Anyway, I hit a large pot hole on the right side and it entered into what can best be described as the "death wobble" I see on the Jeeps, a violent back an forth on the steering wheel, but still tracked straight.

-------
This is what found and it drives MUCH better!

Well I think I found out what it was... Should have been the first thing I should have checked!!!

The wheels were toed OUT, only slightly but but about a 1/16-1/8.

I toed them back in and it is MUCH better, need to get a real alignment now!

The steering box was definitely loose, which was a factor, or maybe a symptom, and it might never have been completely tight.

Pulled over, checked that everything was tight, tie rods are tight, upper lower ball joints appear tight (still on cotter pins), UCA bolts, LCA bolt, etc. Steering box appears tight to k-frame.

Everything in the suspension appears tight; limped it home, with no major issues, just some occasional left right osculation in the front end.

Any thought of what to look for?

Last edited by 6T6Cuda; 07/28/18 04:45 PM.
Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491172
05/02/18 11:04 PM
05/02/18 11:04 PM
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Round Lake Beach, Illinoisy
Rhinodart Offline
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Idler arm, worse set-up on a 67 as it doesn't sandwich between two pieces of metal, a through bolt holds it on at one side. I had it once in my 69 Dart 383 and it was the idler arm. Even if you have a new one on it there still could be issues with it especially with parts made today. twocents


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Re: "Death Wobble" in '67 a-body [Re: Rhinodart] #2491183
05/02/18 11:28 PM
05/02/18 11:28 PM
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ahy Offline
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On alignment, in general, positive caster and negative toe (toe in) promote stability. More of both would be better if you can get it. 1/8" - 3/16" toe in and up to 5 degrees caster.

Still it should not wobble like that. Worth checking for something loose in the steering mechanism IMO.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491191
05/02/18 11:36 PM
05/02/18 11:36 PM
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Someplace you aren't
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Check the tubes in k bar for broken welds. I’ve had those on cars I’ve redone. Fixed before driving, so no idea if it would cause your issue.

What is going on with box? You rebuilt it and it isn’t tighter than that? Adjustment maybe? Problem with coupler?


I want my fair share
Re: "Death Wobble" in '67 a-body [Re: ahy] #2491193
05/02/18 11:40 PM
05/02/18 11:40 PM
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Buford, GA
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Might be hard to do on the ground (ramps? or if you have access to a lift) but you might have someone "wiggle" the wheel between the 11 and 1 you mentioned and see if the linkage is moving up and down. If not, I would tighten the box up some.



Tim


'71 Charger 383/727
'17 Challenger SXT (Wifeys car wink )
Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491238
05/03/18 12:49 AM
05/03/18 12:49 AM
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Grand Prairie,Texas
stumpy Offline
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Slop between 11 and 1 sounds like a steering gear box adjustment issue.

Re: "Death Wobble" in '67 a-body [Re: I_bleed_MOPAR] #2491239
05/03/18 12:49 AM
05/03/18 12:49 AM
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Lincoln Nebraska
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As said, checkout/correct the box first (start with the coupler/shoes). then a good visual/checkout elsewhere since as you know something is loose/misadjusted/bad. Holler how it turns out/what it was.


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Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491302
05/03/18 06:48 AM
05/03/18 06:48 AM
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Cincinnati, OH
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Plan on throwing it on the lift this weekend. Just wanted some ideas, as on the surface (other than the box), everything appears OK.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491308
05/03/18 07:49 AM
05/03/18 07:49 AM
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I'd like a better description of the wheels and tires as well as balance method.

Don't overlook the rear suspension


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Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491392
05/03/18 11:49 AM
05/03/18 11:49 AM
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Cincinnati, OH
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The car has cragger unilug 15" with Cooper Cobra tires. Like a 225/60 or 65? On the front.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491393
05/03/18 11:50 AM
05/03/18 11:50 AM
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Cincinnati, OH
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Had the tires ballaced when the tires were put on. Spinning ballancer

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491403
05/03/18 12:11 PM
05/03/18 12:11 PM
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Denver, CO
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I have dealt with this on 4 wheel drives that had otherwise good suspension- bushings, tie rods, etc. The oscilating you describe, particularly after hitting a pot hole on one side is exactly what one of my trucks would do and you are correct- there is no driving through it.

Check the tightness of the wheel bearings- I know it sounds different or weird but I had just rebuilt my front end, just like you, and sometimes with all that fresh grease etc., you need to go back and retighten. I have a tendency from my drag racing days to set stuff up too loose.

I did that and the truck was perfect.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491482
05/03/18 02:08 PM
05/03/18 02:08 PM
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Try adjusting the centering valve in the steering box that did wonder for my old Plymouth with a ton of free play now minimal

Re: "Death Wobble" in '67 a-body [Re: Paul_Fancsali] #2491587
05/03/18 05:04 PM
05/03/18 05:04 PM
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Wheatfield, NY
Cuda340 Offline
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Originally Posted By Paul_Fancsali
Try adjusting the centering valve in the steering box that did wonder for my old Plymouth with a ton of free play now minimal


Follow the procedure in the FSM.

Re: "Death Wobble" in '67 a-body [Re: Cuda340] #2491608
05/03/18 05:57 PM
05/03/18 05:57 PM
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The centering valve is only in a power steering box, right? I think he said it has a manual box. It sounds to me like your steering box isn't set up right. I would check the idler arm as already suggested, but I would also disconnect the drag link from the pitman arm and make sure the box is set up right. Count the number of steering wheel turns from one extreme to the other. Turn the wheel back exactly half way. This will be the tightest position of the steering box (least clearance). The adjustment for this clearance is on top of the box, there is a jamb nut and adjusting screw. Adjust it until the clearance is just about zero. This should also be the position where you center the steering wheel, too. You may have to adjust your tie rod sleeves to straighten up the front wheels after you re-connect the drag link. I would also make sure you don't somehow have a lot of negative caster. If everything is good and you still have an issue, try changing to another pair of front tires just to rule them out.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491616
05/03/18 06:08 PM
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My hemi dart would go into the death wobble sometimes. couldn't figure it out at first. nothing damaged, went on alignment rack a few times.

I couldn't figure it out until it happened really bad, then when pulling into the driveway my oil pan scraped the ground where it never had before. the front end was riding lower. if you watch a drag car do a big wheel stand, when it comes down hard the front end shakes for second before the suspension recovers and lifts the car. in my case the torsion bars were weak and wouldn't lift the car out of it. If I hit a bump or on hard deceleration it would go into the shake.

This goes against normal thinking as it is a scary situation, but if it happens again hit the gas for a second and see if it lifts out of the shake. might want to check your ride height, and that your torsion bars still have enough spring in them to snap the car back up to its proper ride height.

might be a different issue in your case, but that is what I was up against.


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Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2491637
05/03/18 06:59 PM
05/03/18 06:59 PM
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i did some front end work at my brothers house once and we eyeballed the toe. it was toed in a bit too much, it would do what is described in the original post. at certain speeds if i hit a long bump that would really oscillate the suspension, it would really turn into a handful.
got it aligned and i never noticed it again.

Re: "Death Wobble" in '67 a-body [Re: Rhinodart] #2491936
05/04/18 12:57 PM
05/04/18 12:57 PM
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Originally Posted By Rhinodart
Idler arm, worse set-up on a 67 as it doesn't sandwich between two pieces of metal, a through bolt holds it on at one side. I had it once in my 69 Dart 383 and it was the idler arm. Even if you have a new one on it there still could be issues with it especially with parts made today. twocents


All it takes is a few scraps of metal and a welder to correct that. Did it on both of the 66-67 I used to own.

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2523250
07/17/18 08:30 PM
07/17/18 08:30 PM
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Cincinnati, OH
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Well I had a chance to get it on the lift, think this might have been a factor...


All three bolts finger tight, and one completely loose...

Re: "Death Wobble" in '67 a-body [Re: 6T6Cuda] #2523252
07/17/18 08:36 PM
07/17/18 08:36 PM
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There ya go!!


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