Thread: Need diagnostic help on SEVERE steering wheel shake

Tweet

Originally Posted by Itoldyouso

Sounds like a classic case of death wobble, ... Whose front end kit is it? Did you install it or have it done, or maybe you bought the car this way. Has it always done this, or did it just start. You provided a lot of info, which is good, but I think you need to give more specific info about the front suspension/steering, as that is probably what is causing it.

Don

Car came with the front end as is, as near as I can tell it's an early 1980's Mustang II front end. manual rack/pinion. All I did with it was add adjustable coil overs and replaced all the bushings. My buddy, a shade-tree mechanic, races a Mustang with the same front end set up, just larger discs, so he was familiar with it. After which, the last thing done was to replace the manual brakes with power. It did not do this until after my buddy & I replaced the manual brake system with power booster/dual master...
Classic case of "don't fix it if it's not broken"?

Before the coilovers and power brakes, did the car ever have any issues? How many miles do you think you drove it prior to the new work? Do you know whose kit was used to put the MMII stuff on the car? Are those rods I mentioned in place or omitted?

Don

Originally Posted by Itoldyouso

Before the coilovers and power brakes, did the car ever have any issues? How many miles do you think you drove it prior to the new work? Do you know whose kit was used to put the MMII stuff on the car? Are those rods I mentioned in place or omitted?

Don

Only issues were related to some wandering and hard as a brick braking... drove the car a couple hundred miles before laying her up to work on. No "Death Wobble" at all. Sorry, Don't know whose kit was used as the installation was done almost 20 years ago and PO has no idea. Don't see an steady rods installed.

I reread your original post and you said you had it aligned. What specs did they use? Reason I ask is that I think I remember seeing somewhere that if your MMII suspension has power steering they like a little more caster than a stock Pinto/'MMII would call for, something like 3 degrees, I think. Could it be that when you changed the coilovers you also lowered the front end, which would reduce your caster? Insufficient caster can cause some goofy handling issues, like you describe.

Don

Originally Posted by Itoldyouso

I reread your original post and you said you had it aligned. What specs did they use? Reason I ask is that I think I remember seeing somewhere that if your MMII suspension has power steering they like a little more caster than a stock Pinto/'MMII would call for, something like 3 degrees, I think. Could it be that when you changed the coilovers you also lowered the front end, which would reduce your caster? Insufficient caster can cause some goofy handling issues, like you describe.

Don

Looking at the paperwork, they used the specs from a 1974 Mustang. I did lower the front end, when running 155.60.15's, but since have raised it back to original height & I put on 185's yesterday.. problem still evidenced this morning.
Any possibility that the problem is related to the caliper's? though I see no scoring on the disc surfaces... just a thought.

Something is loose in the steering/suspension, whoever inspected it missed something. Did they unload the ball joints when they checked? You may not be able to detect a bad ball joint under load. The death wobble Pops refers to on beam axles is usually loose king pins which allow the harmonics of the rotating wheel/tire to do the wobble. Very likely that at least one of the components that holds the wheel straight is loose or broken. Strut rods like Pops mentioned would show up on braking too, so another symptom to check.

Originally Posted by Bob Parmenter

Something is loose in the steering/suspension, whoever inspected it missed something. Did they unload the ball joints when they checked? The death wobble Pops refers to on beam axles is usually loose king pins which allow the harmonics of the rotating wheel/tire to do the wobble. Very likely that one of the components that holds the wheel straight is loose or broken. Strut rods like Pops mentioned would show up on braking too, so another simptom to check.

I don't know if they did unload the ball joints, so I'll put her up on the lift later today and look. Will check the strut rods as well.

Strut rods..........thanks Bob, couldn't remember the correct term.

Don

MM II front end with the stock type lower arms only need the strut rods, because of the narrow mounting, the ones with the wide spread don't use them.
Sounds like they said, something must be loose, and you missed it. Are you sure your new rims are seated all the way to the rotor flat, and not hanging up on the center of the bearing hub somewhere?

Pat