Bent rim?
He may be an expert, but what are the alignment specs? Did he give you a print out?
Bent rim?
New Tires and balanced
Well then, lets just move on then! Just so you know, two things. I was in the tire, alignment and suspension business a LONG time. I've seen separated tires unloaded BRAND NEW right off the truck. New doesn't always mean good. But hay, they're new so forget about um.
Think about this.......does it start after the car has been driven a bit? If it does, that could be that bad tire heating up and gettin wonky.
It could be a lot of things, but my point is, don't just say "oh the tires are good" and move on just because they're new. You're looking for something causing a problem, so look at everything.
Do you have somebody close to you that you could put their tires and rims on your car and take it for a drive?
Not enuff + Caster, causing "shopping cart" wheel shimmy.
Prob set to factory specs. for bias tires.
Check the alignment setting from the alignment shop, if the caster is near "0", or negative -
Try having the alignment set to attached chart for radial tires.
View attachment 1715318313
Bad tire/balance, with bad shock is viable, - brakes - not so much.
The fact it's got + Camber, while most modern radial equiped cars run neg, leads me to believe that the alignment was set to original bias ply spec.
Take it back and ask nicely if they could possibly try to get it closer to the chart posted.
Achieving neg camber will help in the adjustment toward +. Caster.
The more + Caster will give you greater directional stability.
It may be nec to install Moog K 7103 offset bushings to achieve more than 2 1/2* or more caster, if you're a spirited,competitive driver.
jmo
Good luck.
Be sure the axle housing is holding the weight so the geometry is correct.I wish I did, but I do not. I am going to put the rear up on jack stands and run it up to speed and see if I get the shake and try to narrow the issue down.
Perhaps not,
It's not what I was expecting, but it isn't right either, and should be corrected, to eliminate it as a likely possibility of shudder, - before some of the alternate suggestions.
The fact it's got + Camber, while most modern radial equiped cars run neg, leads me to believe that the alignment was set to original bias ply spec.
Take it back and ask nicely if they could possibly try to get it closer to the chart posted.
Achieving neg camber will help in the adjustment toward +. Caster.
The more + Caster will give you greater directional stability.
It may be nec to install Moog K 7103 offset bushings to achieve 2 1/2* or more caster, if you're a spirited,competitive driver.
jmo
Good luck.
Per the chart posted earlier it is correct. Or am I reading that chart wrong? It's on page 1.Just want to be sure.
The Skosh chart is used as a guide for "preferred" alignment specs. It does not reflect what the factory service manual says, or the range of acceptable specs that the service manual gives. It's a good chart to use, but the alignment specs posted from the car are correct and in spec according to the factory service manual. That alignment is not the cause of the shake.
As I mentioned, the print-out wasn't what I expected, and, it isn't right either, but it's better than the (neg) - 1* to 0* caster - the Factory Service Manual spec for late 60 to mid 70's A-body manual steering cars.
I agree it's not the issue at + 1* caster.
Neg caster has little, if any directional stability, hence my concern re. "shopping cart wobble" at FSM spec with neg caster.
I maintain the more POS caster, the better the directional stability.
The shopping cart reference was a real good one......we call um buggies down here, but anybody would understand what you mean. The only thing I see that would really negate any of that to me......and I could be way wrong.......would be the steering linkage. As long as everything is in good shape with no extra slop, I think that would keep and buggy wobble, lol, at bay
I could be wrong, it's happened a time of million before. lol