tired of spending $ for a front-end alignment, when all they do is adjust the toe? (1 Viewer)

[REZARF]

I'm shopping now....looking for 37" MT/R's. These SuX's CAN NOT be balanced. Took Pin's idea above and held a chalk line to the thread while they were on the heavy truck tire balancing machine....over half an inch wobble side to side on the tire. Maybe selling them or just keep them for hard-core trails and run the MT/R's for the lighter stuff and highway.

Hats off to Becker Tire in Wichita, 3800 block of west 30th S., for all their help and time figuring out how far off the tires are.

66fj40x2-

I had the same issues, same speed, same problems. I was running only 33's though, I replaced it all, steering stabilizer, TRE's, rebuilt my knuckles (messy job), new center arm the WORKS!... still had death wobble.

Bit the bullet dropped the cash for some 35" MTR's and my truck drives like a dream now. Seriously, if you are using your rig on the road at all, I couldnt recommend the MTR's more, they are really nice driving tires, and they dont wander or WOBBLE!

Best of luck, the death wobble was hands down the most frustrating thing delt with on the cruiser in over 6 years!

Rezarf <><

PS Summit Racing can get the MTR's to your door cheap! (well for a 37" MTR anyway)

 

[66fj40x2]

The kicker is I traded my 35" MT/R's for the SuX's....going bigger and all. They are a good off-road tire, tough as hell, and I'll prolly keep 'em, but the MT/R's are IMHO the finest on/off-road money can buy.

Discount tire can get the 37's in OKC for $188 (according to the web site). Trying to work a deal on Pirate for a set now I think shipping may kill the deal.

 

[jwest]

All these methods only measure relative difference, correct?

That being, the difference in distance between the two front wheels on the stern side of their rotation, subtracted from the distace between the two front wheels on the bow side of their rotation. Wherever or however you measure, as long as you're consistent, all you're measuring is condition. Toe in, neutrality, or toe out, right?

But my question is, how far from the center of rotation is the degree of toe in/out measured?
Say for example, 3mm toe in. How far from the centerpoint, the center of the hub, if you will, is the measurement established and set?

My point is that a distance measurement (inch or mm) varies by the methods used.
The farther from the center of rotation you measure, the greater the difference in numerical value.

For example, on the same vehicle, measuring 10" fore and aft of hub center in the first example, will yield you one measurement. Yet, using a 36" tire as in the next method, (roughly 18" fore and aft from center) will yield a completely different result.

.

 

[REZARF]

All these methods only measure relative difference, correct?

That being, the difference in distance between the two front wheels on the stern side of their rotation, subtracted from the distace between the two front wheels on the bow side of their rotation. Wherever or however you measure, as long as you're consistent, all you're measuring is condition. Toe in, neutrality, or toe out, right?

But my question is, how far from the center of rotation is the degree of toe in/out measured?
Say for example, 3mm toe in. How far from the centerpoint, the center of the hub, if you will, is the measurement established and set?

My point is that a distance measurement (inch or mm) varies by the methods used.
The farther from the center of rotation you measure, the greater the difference in numerical value.

For example, on the same vehicle, measuring 10" fore and aft of hub center in the first example, will yield you one measurement. Yet, using a 36" tire as in the next method, (roughly 18" fore and aft from center) will yield a completely different result.

.

huh?...

Actually, I would think that the plane used to take the measurement, should in theory, extend infinatley, only more acuracy would be gained by extending your reference marks... at least with zero-ing in your toe

But I do see where you are talking about at what distance do you measure the actual toe in, right?

Center of rotation or close to it, would yield the most acurate measurement...

Rezarf <><

P.S. I just made all that up! I dont have a clue

 

[mr_manny]

This is an interesting point...so my 1/16th toe-in measurement at 10" out is not the same at the edge of the rotor and not the same as something closer to center (slightly in front of the center of the rotor).

The professional alightment shops attach there equipment onto the edge of the rim, so would that equate to a measurement just outside of the rotor?

Does there equipment take the wheel size into consideration?
Does anyone know what the actual reference/measurement points are used?

My current toe settings are a definite improvement over what it was
manny

 

[REZARF]

Still a sweet set up for toe in stuff...

Maybe someone here knows!

Rezarf <><

 

[yooper]

I use push pins. Stick a push pin in the front of each tire and measure the distance between them - the pin makes a convenient place to catch the end of the tape measure. Then back the truck up until the push pins are pointing straight back and measure again. Adjust the toe with the tie rod, measure in back again, pull forward until the pins are in front, measure again. Rinse and repeat.

 

[projektdotnet]

Rinse and repeat.

yooper that is great!!!

 

[IDave]

Yes, it is.

 

[FJ40fiji]

Every alighnment spec I ever saw was in degrees, but I haven't looked up my cruiser so I don't know how it is expressed. But yes, the distance away from the point of rotation (trunnion, or king pin, not hub, but close enough for all intents and purposes) at which you make your measurement does influence your results. Measuring the difference between the front and back of the tires, or angle irons or what ever began as just kind of a way to estimate what the angle was (use a little geometry because it is easier than actually measureing angles). But since almost no one is running stock tires A: measureing off the front of the tire will give us all different dimensions, B: Our ideal settings are going to be unique to our suspensions and tires. That said, I'd recomend picking an above method (we all need at least a little toe in) and trying it. Then observe your tire wear and handleing and make adjustmenst as suits you.
To help you visualize why it would be different at different distances, imagine a triangle that points down and is very tall. If your axle were at the top, and the sides were angle iron clammped on then imediatly in front of your axle there would be some distance between the sides, but as you move away the distance is less until the sides meet. If you extended the lines past the axle towards the rear they would be increasingly seperated. At the distance where the sides are touching in the front, you'd be subtracting zero from your rear measurement.
The equiptment at an alignment shop should be measuring the angle of one tire relative to the other with both pointing forward. If you are not pointing forward, the alignment should change (Akerman steering principle) so try to be centered.

 

[FJOE]

Yooper I like this..."I use push pins. Stick a push pin in the front of each tire and measure the distance between them - the pin makes a convenient place to catch the end of the tape measure. Then back the truck up until the push pins are pointing straight back and measure again. Adjust the toe with the tie rod, measure in back again, pull forward until the pins are in front, measure again. Rinse and repeat."

 

[FJOE]

I use push pins. Stick a push pin in the front of each tire and measure the distance between them - the pin makes a convenient place to catch the end of the tape measure. Then back the truck up until the push pins are pointing straight back and measure again. Adjust the toe with the tie rod, measure in back again, pull forward until the pins are in front, measure again. Rinse and repeat.

Can I use a couple of nails? Just kidding.....

I find it unusual that no one mentioned the rear axle thrust. making sure the rear axle is square to the frame is important to minimize dog-tracking. This can also be done with a chalk line easily. If the axles are perpendicular to the frame all sidewalls on on side of the vehicle should be able to touch a taught string held the length of the vehicle at spindle center . maybe this will help since we are talking about alignments that can be done at home.

 

[bad_religion_au]

Can I use a couple of nails? Just kidding.....

I find it unusual that no one mentioned the rear axle thrust. making sure the rear axle is square to the frame is important to minimize dog-tracking. This can also be done with a chalk line easily. If the axles are perpendicular to the frame all sidewalls on on side of the vehicle should be able to touch a taught string held the length of the vehicle at spindle center . maybe this will help since we are talking about alignments that can be done at home.

can i have that in laymans terms i'm pretty sure my rear axle isn't straight

 

[FJOE]

can i have that in laymans terms i'm pretty sure my rear axle isn't straight

Put a string to the side of your back tire pull it tight all the way to the front of the truck to the side of the front wheel. if the axle is square the string should be able to touch the side walls of both tires at 3 o'clock and 9 o'clock without any gaps .

Hope that clarifies it for you.

 

[bad_religion_au]

Put a string to the side of your back tire pull it tight all the way to the front of the truck to the side of the front wheel. if the axle is square the string should be able to touch the side walls of both tires at 3 o'clock and 9 o'clock without any gaps .

Hope that clarifies it for you.

indeed it does

 

[Jerry D.]

I use the push pin method for the toe, one pin in each tire at its center line, one piece of string with reference marks on it.

I have heard there is a difference for the toe distance with radial and bias tires due to their characteristics to wander and/or track. I’ve set both the same way and haven’t notice any problems.

Should this be of any great concern?

Jerry D.

 

[jimkyser]

Put a string to the side of your back tire pull it tight all the way to the front of the truck to the side of the front wheel. if the axle is square the string should be able to touch the side walls of both tires at 3 o'clock and 9 o'clock without any gaps .

Hope that clarifies it for you.

Actually, that really shouldn't work for an FJ40, or most any other car, for 2 reasons.

1.) The FJ40, like most vehicles has a slightly wider track width for the front axle than for the rear (55.3" vs. 55.1"), so the outer surfaces of the front and rear tires should be in separate but possibly parallel planes. As such, even if you steered the front tire to be perfectly parallel to the rear, the front edge of the rear tire should be missed by the string. Yeah I know, it's only 1/10" but this should still be true.

2.) If the FJ40 is properly aligned, the front axle will have a few degrees of toe-in as discussed earlier in this thread. That means that the outer surfaces of the front and rear tires are in skewed, not parallel planes when the front wheels are pointing 'perfectly' forward . This should cause the string to move even farther away from the front edge of the rear tire and if you tape the string to back edge of the rear tire and bring it in slowly until it just touched the back edge of the front tire it shouldn't be touching the front edge of the front tire either.

 

[tyama]

I'm glad this thread came back. I was just about to take the 'nilla ('70 fj40) to the tire shop and decided to do it today with some angle iron. I measured 8" instead of 10" and discovered the front was 5mm wider than the back. Now that it's corrected, it looks like the caster shims are right and all I need is to get the 34" super swampers balanced.

Good thread. ty