I've Got The Shakes!

[Movin]

^^ right on. A car with excellent road feel and that is light and quick has to have near perfect cross balance and a tire that stays round at speed.

Don't let your pleasant road feedback turn into a shaky irritation !

[sc72]

For you fellas that say you had your tires balanced and it still shakes, were they balanced on a standard balancer or did you have them balanced on a road force machine, there is a lot they can do with that machine, it can detect if you need to rotate the tire on the rim to help with the balance.

[Movin]

Just like tires, there is a huge difference in machines.
Those using them will really enjoy a very good machine.
The result for the customer is they will really enjoy no shakes.
BUT polishing a turd is just a shiny turd!!
Everything has to be quality from beginning to end just to have
any sort of quality. A chain is only as good as the weakest link.
Start with a good tire. Use a perfect rim. Make sure it fits tight
and perfect. Use the right lug and lug nut for that rim. Torque
in steps .

Now the important part, polish with a clockwise pattern on the right
side wheels and counter clockwise on left side wheels. Messing this
up can cause spectators to get dizzy. Painting wheels is far more complicated
and can render the best tire balancers useless if paint is not laid correctly.

[Advancedynamix]

My tires were all road force balanced, but with the car on the lift I can spin them and see that they have runout. The wheels are true to the car within .005" but the tires are .060" or more out. You can perfectly balance a square, but it won't offer a smooth ride. Lol.
I've got a set of 15" wheels with 165/45-15 tires that I can try to see if they ride smooth. They were smooth when mounted on Tweak.

[dalebwilson]

My tires were all road force balanced, but with the car on the lift I can spin them and see that they have runout. The wheels are true to the car within .005" but the tires are .060" or more out. You can perfectly balance a square, but it won't offer a smooth ride. Lol.
I've got a set of 15" wheels with 165/45-15 tires that I can try to see if they ride smooth. They were smooth when mounted on Tweak.

:thumbs_up: All of my tires are this way. New or old. I have checked run out on wheels to be minimal but the tires have visible high spots.

[AlaskaFestivaGuy]

I just installed a pair of new 12" Kumhos from Discount Tire on the front of my primary long-distance Festy, which had ever-worsening shakes at 45mph and above. The tires that came off were nearly 10 years old (according to date codes). I left half-decade-old odd-brand tires on the rear. Now, I can comfortably cruise, even at 80mph, even on less-than-perfect freeways, with no shakes whatsoever at any speed.

I've got another Festy up in Anchorage where installing four new tires (probably Kumhos, since they also came from Discount Tire Seattle as checked baggage -- 2 in a box for one SUV wheel), had the same great results.

Only once in my 15 years of Festy ownership have I traced shakes back to something other than tires -- it was a worn-out steering tie-road end ball joint.

[dalebwilson]

Thank you Alaska. That is great information.

I just installed a pair of new 12" Kumhos from Discount Tire on the front of my primary long-distance Festy, which had ever-worsening shakes at 45mph and above. The tires that came off were nearly 10 years old (according to date codes). I left half-decade-old odd-brand tires on the rear. Now, I can comfortably cruise, even at 80mph, even on less-than-perfect freeways, with no shakes whatsoever at any speed.

I've got another Festy up in Anchorage where installing four new tires (probably Kumhos, since they also came from Discount Tire Seattle as checked baggage -- 2 in a box for one SUV wheel), had the same great results.

Only once in my 15 years of Festy ownership have I traced shakes back to something other than tires -- it was a worn-out steering tie-road end ball joint.

[Hecka]

I have a theory about this shaking issue:

I haven't noticed much of a shake until this morning on my drive to work. I got the death shake at 55 mph and it got really really bad, then it would go fine, then shake really really bad again and so forth. The only change I made last weekend was installing new MOOG polyurethane bushings on my front sway bar. I tried to get poly sway bar mounts for the inside part, but the auto parts guy couldn't find any(didn't even attempt to look for universal mounts, but whatever).

So I put the new bushings on where the old ones were. I figured that I could put the mounts back on after the bushings were tightened, but I wasn't able too. I had to loosen the passenger side bushings to get the mounts on. Only after then, have I noticed a horrible shake. And it's a side-to-side shaking of the steering wheel, not an up-down shake/rattle, like what would be indicative of tire problems. My tires are fine.

At least for my issue, I'm going to say that the shaking is due to my sway bar. I don't know if there are torque specs for the nut keeping the sway bar in place, or if I need to loosen/tighten the other sway bar bushing on the driver's side. What I'll probably end up doing is loosen all the mounts and bushings(without taking any of them off), grab the sway bar and shake it back and forth to try and align it back to what it used to be, and then tighten everything up again. I'll do that tonight after work and let you all know what my results are.

[Movin]

When you jack the car up it binds the sway bar bushings, all four. If you find a flat surface somewhere you can put the car in gear or in park if it is an auto. Rock it hard forward and backward like you do when looking for broken motor mounts. If you do this while laying down in the front the sway bar will not be bound up and anything wrong or loose will show up as movement.

Also, you have seen the death wobble on a grocery cart caster wheel, the front wheel. When the caster wheel mount gets bent a little it increases the negative caster and they will death wobble. On your car this same caster is controlled by your sway bar. You may have introduced a part or assembled some parts that changed this adjustment.

[Hecka]

When you jack the car up it binds the sway bar bushings, all four. If you find a flat surface somewhere you can put the car in gear or in park if it is an auto. Rock it hard forward and backward like you do when looking for broken motor mounts. If you do this while laying down in the front the sway bar will not be bound up and anything wrong or loose will show up as movement.

Also, you have seen the death wobble on a grocery cart caster wheel, the front wheel. When the caster wheel mount gets bent a little it increases the negative caster and they will death wobble. On your car this same caster is controlled by your sway bar. You may have introduced a part or assembled some parts that changed this adjustment.

Interesting. . . So should i loosen the sway bar mounts before rocking the car? I was going to try and get the mounts loosened without taking the wheels off, so if I can do that, then I'll loosen it without jacking it up.

Thanks for the advice!

[Movin]

The binding will make it seem tight when it may not be tight on the ground. You want everything tight like road ready to rock the car. If you are not that big it works better to have someone rock the car for you while you look for looseness. Bushing compressing a little at each change of direction is normal, free play is not.

[Hecka]

The binding will make it seem tight when it may not be tight on the ground. You want everything tight like road ready to rock the car. If you are not that big it works better to have someone rock the car for you while you look for looseness. Bushing compressing a little at each change of direction is normal, free play is not.

I never had any free play from what I notices. After I put the new bushings on the first time it was really tight and there was no more knocking noise when going over bumps(I made sure to test that very well). . . So last night I loosened the bushings and mounts(one nut on each mount got rounded from my ratchet:angryfire: so I couldn't loosen one side of the mount, which probably doesn't help) with the festiva level on the ground, no jacks, and rocked the car a few times with it in gear. Then I tightened it back up, but not as tight as I had done last time. I just got it past the cotter pin and snug, using the ratchet. I replaced the pins back in the holes and drove it to the store and back. I wasn't able to get it to the speed that I needed to see if there was actually any difference.

This morning I drove to work. The shaking isn't gone. It's very slightly better, but definitely still bad. The weird thing is, it goes away for a few seconds, then comes back with quite some force, then goes away again slightly, then comes back. I may need to loosen the mounts and bushings to very very loose and rock the car again, unless somebody has another suggestion.

I read in this thread that the caster could be affecting the shake, but I have a hard time believing that I did anything to the caster. I bought thess "camber adjustment bolts" that I haven't installed yet because I don't have any way of measuring the alignment on my car. I have an alignment scheduled for with my local tire shop, and I bought new tires for my wheels which they'll be mounting tomorrow as well. I'll tell them about my problem with the shakes and hopefully they'll troubleshoot it.

[Movin]

There are several ways to wiggle things both on the ground and in the air. Anything that has a joint has directions it should move and directions that forces come from that wears until unwanted movement starts. The trick is to be aware of the stresses on the joint from the springs or the weight of the car and figure out a way to test for unwanted movement by wiggling, prying, barring, shaking, bouncing , rocking , pushing and pulling until you find it.

[Hecka]

OK! I guess the whole sway bar issue was just a major coincidence. I just had my tires replaced with these this morning: Achilles ATR-K Economist 165/55R14XL 75V BSW

These tires are too soft for me, but I'm going to ride them out and see if there's any difference after getting an alignment done.

I didn't get an alignment done, because the tire guys said that my inner tie rods are bunk. I will be going to rockauto and buying new inners and then I'll have them install the tie rods and do the alignment.

The ride is so smooth now, but it's also really sloppy. I'm hoping that getting the new tie rods will fix most of the slop, but I don't really like these tires. If anybody else has 14 inch rims, I don't recommend getting these, unless you're fine with going in a straight line most of the time. This car is my commuter, and I mostly go in a straight line with it, so that's why I'm keeping these tires. They make the ride slightly quieter and bumps are smoother as well, which is nice.

These are lower profile tires than my other ones, but the rubber must be much softer.

[Movin]

It seems they like to make one rubber chemistry fit everybody unless they are race use. With the car in the air pushing and pulling away from you and toward you with both tires at the same time will show the inner tie rod.The left bushing of the steering rack is also a wear item. Some alignment guys will miss this. laying under the car in the same position that you reached both tires at the same time, reach up and grab the drivers side tie rod. push up and down on it. If you have play that way pull the boot back so that you can see the rack move. While there you might make sure you have the right wrench to remove the inner tie rod.