Toe setting moving, all new or reman components installed

[ChrisB]

After putting everything together with poly bushings...set toe at -1/16 (toe in). Drove it five minutes came back and toe was + 1/4. Set it again this time to '0', drove it 2 minutes, came back and -3/16 to -1/4. I will be checking it again after a 50 mile freeway drive tonight, it surprised me there would be that much movement.

Anyone check the toe enough in quick succession to see this?

New disc brakes and all other comonents make a big improvement. Brake effort is almost too low and feel too firm, too much authority. I didn't think I'd have to look into it, but guessing I may have too much front brake bias. What a ride...

[70_F100]

A lot of this depends upon your toe-checking procedure.

If you're jacking the front end up to mark the center of the tires (where the toe should be checked), the I-beams swing in and change the toe. You have to move the truck far enough to get everything to settle down before checking. This usually means that the marks have long-since disappeared before you get everything settled down.

If you're checking without raising the truck and marking, and you're just measuring from the center point of the tread, there's a distinct possibility that you're not actually getting the center point of the tread, due to tread design, wheel wobble, etc.

If you're measuring from the inside of the wheels, you're not getting the correct measurement. The radius of the circle is not the same at the rim as it is at the tread.

To "properly" check the toe, you need some turntables designed specifically for front-end alignment.

Before I would put a lot of time and effort into solving a problem which "may" not exist, take the truck to an alignment shop and have them do a complete alignment, since all of the components changed could have also changed the caster and camber. At minimum, have them check the full alignment (whether or not they can do it completely by bending the I-beams) and have them set the toe. They can then drive the truck (even around the parking lot will suffice) and recheck the toe.

[ChrisB]

Great reply. We have turntables, we also have what we call toe plates. These toe plates have been very repeatable on other vehicles. On other vehicles one can check the front and then check a solid rear axle alignment and get repeatable '0's every time. When we first set the toe the other night we had it sitting on turntables.

Last night, after the first short drive, no significant tire temp introduced, I checked it sitting on the ground. I was able to loosen the toe adjustment sleeve (new) and literally turn the whole assembly by hand,easily, not loose and sloppy, just very precise and easy to turn. I turned it one turn to adjust for the toe out Isaw, measured '0' toe with the toe plates, (manufactured strictly for this purpose) and tightened the sleeve.....drove it 2 mintues, left and right slalom, in and out of a few driveways etc, stopped moderately a few times to check brake feel/start bedding, returned, again with no significant tire temp, ambient temps in the 50s, no speed higher than 40 mph....and the toe was between 3/16 and 1/4 'in or negative'

Now admittedly, these plates are pushed up against the outside of the tire and sit flat on the ground, it's not the center of the tire as a reference, so some sort of sidewall variation undulation what have you could be in effect, but Iike I've said, repeatable results when measuring other vehicle front ends, especially solid rear axle alignment as a point of reference.....

Pulled into large flat concrete floor garage straight ahead when measuring, no jacking. For grins we did check it after having the front tires mounted but off the ground on a lift, put in on the ground, which as you know leaves the tires cambered positively until the vehicle or steering is moved quite a bit. The toe was found to be 1/2-1 inch negative (in) which we considered to be normal given the droop in the beams and its effect on the steering arms etc....

Maybe this is just settling in of new components. The poly bushings are the main thing on my mind....

[ChrisB]

Just checked it again on a flat concrete floot with same plates and after 50 miles of highway driving. To my amazement it's right where it was last time I checked. between 3 and 4 16ths negative toe. I am going to set it somewhere between 0 and -1/16th and see what happens the next time I check, need to go run some errands anyway.

BTW, still full of brake fluid after some growing pains seepage here and there last night. Hubs felt ambient temp to the touch after driving 60-65 mph for 20 miles...looking good. Front tires were noticably warmer than rears which always felt almost ambient temp. I couldn't feel a difference between outside block and inside and middle of the tire.,,,,notion being that excessive toe in either direction will increase heat and probably show more to one side or the other depending on whether the inside or outside of the tire is 'leading' so to speak.

[ChrisB]

Alright, again, could easily turn it by hand, wow, I could get use to this new stuff.

1/2 turn of the sleeve set it to -1/16, not having the specs in front of me, I'm guessing that's probably about right for going down the highway with the least drag. Wouldn't if be great to have an alignment machine that checks while you're headed down the road or at least somehow compensates for the rearward push on the front wheels....

[70_F100]

Alright, again, could easily turn it by hand, wow, I could get use to this new stuff.

1/2 turn of the sleeve set it to -1/16, not having the specs in front of me, I'm guessing that's probably about right for going down the highway with the least drag. Wouldn't if be great to have an alignment machine that checks while you're headed down the road or at least somehow compensates for the rearward push on the front wheels....

It's been a few years since I did alignments, but most vehicles I have aligned called for around -1/16 to -3/16, meaning the preference is -1/8.

The point of toeing it in is to compensate for that rearward push of the tires. Once you get moving, the toe changes to nearly straight ahead. If it were toed to zero, moving down the road it would change to toe-out.

[ChrisB]

I think right now I'm just chasing the settling in of this stuff. That -1/16th turned into about -1/32nd to zero so probably -1/32, The good thing is things are calming down, no wild swings. I'll keep watching to see what happens and hopefully settle in on somewhere in the called for range.

I haven't put the digital meter on it, not handy at the moment, but it's looking like I may have a slight positive camber issue now, as in more than it may have had before. IIRC, when I measured it a ways back it was straight up to maybe a tenth of a degree or two positive. Truck didn't get any lighter.

These brakes are almost too easy now. Ihaven't tried hard, no snap braking etc. but I haven't had any rear lockup yet. I've left my old wheels/tires on for the interim so they don't get brake fluid on them/flat spots....who knows....

Moral, don't change bushing etc. set the toe yourself or have it aligned and then just forget about it. You're better to set it close yourself preferably then after say 50-a few hundred miles take it in for a final adjustment.... more to come.