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What are the symptoms of bad toe-in


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#1
mdbrandy

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Ok, so I drove my 280Z for the first time in 9 months today! Entire new front and rear suspension! Now I just have to work out the bugs.

I had it up to about 60 for a stretch, and it wandered some. When braking from that speed, I had a high-speed shimmy. At lower speeds, (30-40), no shimmy. I have NOT had it aligned (just came off the jack stands about 3 hours ago). My steering wheel is also about 30 degrees off, so I didn't get things back the way they were before. But with all new tie rods (inner and outer), ball joints, bushings, etc., who knows how it was before!

So anyway, if the toe is really off (either in or out), what symptoms would I expect to see?
Mark Brandyberry
1970 240Z (11/69) HLS30 00215
1978 280Z (05/78) HLS30 466356
IZCC #802 & CZC#4028

#2
cj71z

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After my new lowered suspension I have a toe-in problem. Stand infront of your car a decent distance away with your steering wheel straight and take note of the wheel position either pointing in or out. Did you mark where your old tie-rods were threaded to before removal? My tires are new and I notice that with too much toe-in the inside edge of the tire tread is clean(no road dirt). I'm assuming it would be the opposite with too much toe-out.
1971 Datsun 240Z
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rebuilt SU's, urethane bushings, ST springs, motorsport sway bars, 4-piston brakes, Libres

#3
Spdloader

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Hi, too much toe in will cause your tires to wear on the outside edges of one or both tires if the toe is off enough, and your steering wheel will be crooked.

Too much toe out will cause the inside of one or both of the tires to wear.
It can cause all sorts of weird handling characteristics at different speeds, too, but shakes and shimmys aren't among them.

Chances are the shake is caused by a brake rotor or wheel balance problem.
You should have the vehicle aligned as soon as you can, and have it checked twice a year or so, and keep the tires properly inflated, rotated, and balanced.

If the vehicle is left out of alignment long enough, you can develop a tire wear pattern that will greatly accelerate the wearing of the tires, and that is hard to correct.

Spdloader

#4
mdbrandy

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Hey guys. Thanks for the thoughts. I was really looking for the dynamic effects of too much toe in/out. I know that leaving it out of line will mess up the tires, and I'll get it to an alignment shop before I drive it much. But now that I have it all back together, I need to assess whether it is in good shape, or if I need to redo anything.

The shimmy is only under braking, and only at higher speeds, so it's a dynamic vibration of some sort, and I suspect it will be with the rotor or caliper. But I was wondering if it was toed-out, if dynamic braking could cause any sort of weird behavior. The rotors, wheel bearings, calipers (toyota 4-piston), pads, etc. are all brand new. But that doesn't mean that I didn't mess something up...

On the tie rod setup, since everything is new, I didn't measure the old ones. The Factory manual actually has a distance to set the tie rod lock nut from a flat on the tie rod body, and I set that on both sides. The wheels "look" good from the front. But It doesn't take much I suspect.

Thanks.
Mark Brandyberry
1970 240Z (11/69) HLS30 00215
1978 280Z (05/78) HLS30 466356
IZCC #802 & CZC#4028

#5
Spdloader

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Well, then forgive me for stating the obvious, I wasn't insulting your intelligence.
To answer your more specific question about the alignment causing problems during "dynamic braking", the answer is "of course it will". The effect will be a direct result of the amount the alignment is off.

The opposite of dynamic is static, so the front alignment isn't an issue during a "static" situation. In other words, when you're sitting still, pumping the brakes, the vehicle isn't moving anyway, so the alignment doesn't come into play. I guess I really don't understand your question.

Spdloader

#6
26th-Z

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Sounds to me like it passed the test, Mark. Nothing fell off? Made it home all right? No tow truck involved? Time to get it aligned.

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#7
jmortensen

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Unless there is something wrong with the REAR toe, front toe shouldn't cause an issue under "dynamic braking" unless maybe it is WAY off to begin with. The reason is that the wheels will center themselves and you'll have an equal amount of toe in or toe out on both sides. The steering wheel might be offset to one side to compensate, sounds like you've already experienced that. But unless you hold the steering wheel where it started out, the wheels are going to go as straight as they can down the road just because the force of them driving forward will make them want to go straight.

Why not run a tape measure across and see where the toe is? Just hook into a particular tread on the tire, then measure to the same tread on the tire on the other side. Do this as high up as you can on the front side and the back side. Subtract the difference, there is your toe.

If you're all stock then front toe is your only adjustment you can make. You can get it close enough without having the car aligned by a pro. If you want to know where caster and camber and thrust angle are, then you'll need a real alignment.

To fix the steering wheel issue there are a couple of things to take into account. Most important, did you get the tie rods on evenly? Is one tie rod threaded in 3/8" more than the other side, or did you put them on evenly? If not, go back and even them out before you adjust the toe. You can see if they're even by the number of threads showing on the inner tie rod. If you don't even them out you'll end up with the ability to turn farther left than right, or vice versa. Once you have them even, you lock the steering wheel in place (always nice to have a helper to just hold it straight). Then you adjust the toe as necessary, toe in of about 1/8" on front is pretty good for street. Then you lock everything down and drive. If the wheel points slightly left or right, you move the tie rods, not the steering wheel. If it points left you need to move the tie rods left, meaning you need to lengthen the right tie rod and shorten the left. As long as you do this in an equal amount the toe won't change. So you can go 1/8 turn on both sides, lock it back down, drive again and see what happens to the wheel.

Should take about 20 minutes to adjust front toe. It's pretty easy, and every time I've done it with a tape measure I've been within 1/16" on the alignment rack. The rest, caster and camber can be done with a modest degree of accuracy with a bubble gauge, but REAR toe is very hard to adjust without an alignment machine, because the tires could have 0 toe but still be pointing off slightly one direction or the other, making the car crab down the road. If this happens on the front the steering wheel turns to compensate. No steering wheel to compensate in the back, so it will actually drive the wheels to the left or right. You might have seen a Volvo crabbing down the road, they're notorious for that problem.

Unfortunately in a stock Z only front toe is adjustable, so anything out of whack on the caster, camber or rear toe is going to require some pretty big modifications to fix, probably adjustable camber bushings at the least.

EDIT-Your shimmy is probably loose wheel bearings, or warped rotors. Could be wheel bearings are too loose, I would also say that bad tie rods or ball joints could cause this but that shouldn't be the problem in this case.

#8
mdbrandy

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When braking from that speed, I had a high-speed shimmy. At lower speeds, (30-40), no shimmy. I have NOT had it aligned (just came off the jack stands about 3 hours ago).


Well, I figured it out. The toe was quite off, but that wasn't the problem.

I had installed new slotted/drilled rotors from MSA. I noticed no problems with them when I installed them. However, after a lot of searching through the front end, retorquing things, readjusting wheel bearings, etc, I finally found that the right side rotor had apparently been dropped. There was about a 3/4 inch area on the inside outer edge that was a little flattened, and that had pushed a small ridge of metal away from the surface of the disc. So every time the disc rotated, it hit the pad. The ridge was small enough that under no, or low braking it didn't cause symptoms, but when hauling the car down from speed, it was carving a groove along the very outside edge of the inner pad and causing a shimmy. Had it "skim-turned" to remove the ridge, and it is fine now.

Wish I could have returned it to MSA instead of paying $12 for the turning, but it has been a year since I bought it, and I already had to return them once because they sent me 240Z rotors instead of 280Z rotors. No way they'd take them back (I didn't even ask). And I couldn't prove that I didn't drop it myself anyway. So, mystery solved. And I'll remember to inspect carefully every inch of all parts I buy, whether I'm busy or not...
Mark Brandyberry
1970 240Z (11/69) HLS30 00215
1978 280Z (05/78) HLS30 466356
IZCC #802 & CZC#4028




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