Death Wobble in Steering Wheel

[ramsesosirus]

So I took my mostly stock 1976 280z out Monday for the first time in 6 years after replacing the blown engine (replaced with a 79 2.8 L).  

Ran pretty good, but at speeds above about 30 mph, I would get an intermittent "Death Wobble" in the steering wheel.

The steering wheel would vibrate/shimmy back and forth, I actually pulled over to see if I had blown a tire.  

Jacked it up, steering wheel locked: no play up and down (pushed at 12 and 6).  Decent play side to side (pushed at 9 and 3).  

Looks like the play is in the outer tie rod ends (might be stock...) so I ordered 2 Moogs.  I have replaced tie rods on other cars before, I know they can be a pain.  I want to get the alignment at least close enough to enjoy a weekend cruise, so I'm looking at keeping the toe the same as it is now (I have normal tire wear).  

Any advice on this job?  I understand you want the leading edge to be about 1/8" less than the trailing edge of the tires for slight toe in.  What exactly do I turn to adjust this once the new ones are installed?  I assume something on the inner tie rods?  (Yes I've read that if I did need to eventually replace the inners, I have to use two RH ones etc...)  

The driver's side is the "reverse threaded" side, correct?  

I plan on just cracking the holding nut loose and using that as the starting point.  But I also know new tie rods may not be the exact same length.  

As a side note, what's everyone running for base timing?  It says 7 degrees on the hood.  This engine seems a little less powerful, the stock engine would "chirp" the tires when shifting from 1st to second (automatic, I know, I plan on a manual swap someday, but the one I pulled from a ZX is the "wide ratio", so it might be a dog).

Thanks, i'm really hoping to enjoy this car this summer!  

[siteunseen]

Somebody said "right is right, left is wrong" on the tie rod threads so your right with the driver's side being reverse threaded.  Make a scratch where they are now and count the turns taking them off.  I pipe wrench and a big Crescent wrench worked for me. 

Mine wobbled really bad and the fix for me was having the rotors turned or maybe I just bought new ones? and inner bearings on the front.

I do 10 degrees BTDC on my ZX distributor and could actually go a little more but it runs good all around at 10.

Car looks good!

[ramsesosirus]

Thanks, well there's another thing to look at if this doesn't cure it.  So far I'm thinking the possibilities are:  outer tie rods (changing these), inner tie rods, TC rod bushings, warped rotors, unbalanced or damaged tires.  I can deal with some vibration, but it would literally shake violently, I couldn't look out the window to see if the tires were "dancing" with it since I had to focus so much on maintaining control.

My car is definitely a "20 footer", lots of cracks in the paint and a few chips with rust.  Not bad for a rust belt car that's 41 years old!  Also less stressful to actually drive since it isn't mint.  

[siteunseen]

It looks like new tires!  That's a real big change, at least on mine, especially if it's been sitting for 6 years.  You'll get it figured out.

I paid $50 for an alignment after rebuilding all that steering stuff, guy said it was an "1.5" out" whatever that means.  Couldn't tell what he meant, really busy shop.

[Reptoid Overlords]

When I liberated my ZX from its garage grave, the two mounting bolts that bolt the steering box to the frame were so loose you could hand turn them. Something quick and easy to check..

[Chickenman]

One other thing to check on the wheels. Make sure that the center hub centric is not machined too small. The wheel  will not sit flush with the wheel hub. It can be installed kocked at a slight angle. This won't show up on a balancing machine ( when checking for wheel runout ) as balancing machines use tapered arbors. 

[ramsesosirus]

The car came with a bunch of receipts, showing it was painted in 1988.  Also there was a tire receipt from 2004, which seems accurate.  Up close you can see they aren't new, but still have good tread left.  It's amazing what a little tire shine will do for the picture haha

I suspected the tires, since the car has been sitting for about 6 years.  A couple of the tires have a slow leak, so they would eventually go nearly flat.  But I thought that if the tires were out of round or "flat", then the vibration/shimmy would happen all of the time.  Which is doesn't. 

It doesn't change when braking, it is relatively intermittent, A few times I was accelerating pretty fast, got up to about 50, and had no problems.  Other times it shakes violently at 30.  So it is definitely an intermittent deal. 

I waited six years to drive this thing again darnit!  I guess it's not something I could've noticed when I first started the engine, since I only went around the parking lot a few times slowly. 

Almost never any vibration below 30 mph. 

Edited June 14, 2017 by ramsesosirus

[Chickenman]

And make sure that the steering coupler is tight secure. Especially if it is still the original " Rag " joint. One place where Poly is good. 

[siteunseen]

'76 Z doesn't have power steering but it would be wise to grab the steering rack and see if it moves.

[siteunseen]

I guess I was referring more to flat spots on the tires from sitting so long but that wouldn't cause the wobbly steering wheel just a thumpity thump thump ride. 

[ramsesosirus]

That's what I thought about the tires siteunseen, would be consistent with each rotation.

Funny you mentioned power steering... One of the old receipts I have from the PO (friend's brother) was a general check up and change all fluids.

I was thinking "Oh great, all the fluids were changed not long ago"  until I got to the line that said he flushed the power steering system for $75....  I won't be going to that mechanic....

 

I did move rotate the steering wheel with the wheels off the ground, and it seemed pretty responsive to the wheels, no "play".  I looked at that round "rag joint", seemed good.  I plan to do these tie rods tomorrow or Friday and see if it improved. 

Granted, when I did inspect it, the sway bar links and bushings and probably most of the other bushings/rubber could use a refresh at this age.  I just want it "cruiseable" for now.  I have too many tickets already. 

Thanks

[esmit208]

3 hours ago, siteunseen said:

It looks like new tires!  That's a real big change, at least on mine, especially if it's been sitting for 6 years.  You'll get it figured out.

I paid $50 for an alignment after rebuilding all that steering stuff, guy said it was an "1.5" out" whatever that means.  Couldn't tell what he meant, really busy shop.

Looks cool even siting on the alignment rack!