Toe-in, Toe-out

[mark]

Not being an alignment specialist, how much does toe-out effect handling. My rig has always been a bit of a hand-full at "high" trail speeds. Kind of floaty-wallowy. Not a big deal at crawl speeds, but since I built it to play/race/tuff truck, I kind of would like it to handle a little better.

I'll have to check caster, but I'm pretty sure its good as when I build the front axle I made sure to dial it back, however when I built the tie-rod I remember messing up and it ended up a little toe-out. I need to cut it down but I haven't yet. How does a little toe-out effect things?

Front locker probably doesn't help, nor the tires in the single digits right now, but the symptoms I'm dealing with are when your flatfooting it in loose traction (say, such as a snow covered residential neighborhood) the whole truck gets very floaty and light in the front end and I end up correcting side to side quite a bit and borderline fishtailing most of the way. Especially noticeable if your powering out of a turn or started sideways (never happenes ). I'd really like it to be rock solid.

Noticed it racing at straddleline last year and also bombing the logging roads at Naches last summer.

 

[83yota1]

Think of it like this, when you're in a toe-out situation, your tires are already starting to turn even when going straight " \ /" This can make it feel twitchy depending on the severity of the toe out. Road race cars Ive set up demand some toe out to help initiate turn in. For higher spped stability a more neutral setting could help your twitchiness.:awesomework:

 

[skinny_pedal]

Toe will not create a pull. Caster will cause unstable steering. Camber will cause a pull.

 

[CHOP SHOP]

Solid axle gets no toe in or out if all is tight.

Some will toe in a solid axle to allow for sloppy parts or wear. If parts are sloppy or worn and set straight ahead then the slop will allow it to wander to the toed out position and affect driving ability.

Tires also play a large part. Bias tend to need a hair of toe to compensate for carcass flex while radials can be set straight ahead if the axle is tight.

 

[CHOP SHOP]

Any advice that compares your application to a IFS car or truck should be disregarded.

 

[TreeClimber]

On my CJ, I set the toe with a tape measure. The front is toed in 1/2 inch, when compared with the rear of the tire, I stick a thumbtack in both front tires, measure the distance, then rotate both front tires 180* and re-measure.

This was how I did it on my bias 33 Swampers on my CJ5.

Now that I'm radial 37 Krawlers on my YJ, I still do it the same way.

All the front end parts are tight.

Drives at 70 MPH nice and straight, with no weird characteristics. Does a nice job of returning to center when you let your hands off the steering wheel.

 

[jeepmauler]

My last 3 wheeling rigs I've set the toe at .25 IN...thats with 37"+ tires. The XJ truggy had a steering box with drag link etc and drove like a champ on/off road. The last two are buggies with full hydro and stable up to triple digits

 

[Fordzuki]

To start, 1/16th to 1/8" toe in is pretty standard. If your tires are toed out excessively, the vehicle will do exactly as you are describing, and seem to "pull" one way or another, because you are essentially driving one tire straight, while dragging the other one. As traction and power differentiate, the tire with traction is going to want to pull straight, while the other will drag. The transfer from one side to the other is what you're feeling in the wheel/vehicle. This will be way less noticeable when in rwd than 4wd and fwd.

 

[WA-Wheeler]

Anything with over sized tires I suggest toe in. But i have seen some picky rigs out there, might need to play with it a bit.

Best of luck :awesomework:

 

[superglock]

I have done alignments and wih power steering I have only seen toe in, 1/16 to maybe a 1/8 in. When they are toed out each tire is going a different direction, When its toed in tires are pointing at the same point and will give it stability. Also as you change tire size it will change toe.

 

[mark]

Thanks guys. Sounds like as I suspected. I need to recheck it and dial in a little bit of tow-in and see what happens.

Draglink ends are "new", so they should be tight, Tie-Rod is new heims and they haven't been run enough to be sloppy. No guarantee on ball-joints, that are what ever was on the knuckles when I grabbed them, so I'm not relying on them being tight

 

[Peanut Gallery]

For caster the more negitave caster you add, the wheel will want to return to center. So if you are coming out of a corner and let go of the wheel it will center itself.

 

[tmill]

so just to clarify because this always confuses me. Negative castor would be end up poining the pinion up higher and positive castor would point the pinion down?

 

[t1h5ta3]

so just to clarify because this always confuses me. Negative castor would be end up poining the pinion up higher and positive castor would point the pinion down?

yes, if you are rotating the entire housing to do it.

 

[tmill]

thanks, ran into a bit of a problem today on my build and this will help a ton. i was setting it backwards

 

[mark]

so just to clarify because this always confuses me. Negative castor would be end up poining the pinion up higher and positive castor would point the pinion down?

thanks, ran into a bit of a problem today on my build and this will help a ton. i was setting it backwards

Actually, I've seen the SAME drawing that Brian has posted labeled BOTH ways. But the one shows is what *I* have always called correct. It just makes sense to call POSITIVE caster the desired caster direction. So it doesn't matter what you call it, as long as its set up like the first [positive] diagram above, you should be golden.

Anywhere between 4

 

[Grommit327]

I set my caster at +6

 

[84Toyota4x4]

Caster is pretty easy when you think about it. Positive caster (like a bicycle or a chopper motorcycle) will be more "self centering" and resist turning (riding a bike with no hands). Negative caster (like a shopping cart or office chair caster) will be more "twitchy" and easier to turn.

Hows the thrust angle on the truck? Run some strings from the rear axle to the front (WMS to WMS if possible) and see what that looks like. This can cause some strange behavior on hard acceleration. Strings and dowels can get you a damn good alignment if you can think outside the box and know what to do with them.

As mentioned, I run about 1/2" total toe in on my truck, I think it wanders the least that way with the bias tires.

~T.J.