School Me On Front End Alignment?

[Nothing Special]

.... And while you are reading what the FSM says, I wonder if the spec's are wrong. Surely it should have said .025 degree, meaning from .035 to .085 degrees....

This is just me applying the sniff test, but a tolerance of +/-0.025 deg doesn't smell right. +/-0.25 deg seems fairly tight to me. A tenth of that? No way.

And I wouldn't get worked up about the fact that the tolerance is twice (or even four times) the nominal. The value of the nominal is very subjective based on where it's referenced from. If the nominal was measured off the axle axis it would be 89.94 +/- 0.25 which wouldn't raise any eyebrows.

Still, it seems a little odd to me that they don't mind that much toe out. I'm no expert, but it seems like I've always heard you want neutral to slight toe-in. (And yes, I do get that if the tolerance was less than the nominal that it wouldn't allow toe-out, and I'm tearing my previous argument apart!)

[Gary Lewis]

.... And while you are reading what the FSM says, I wonder if the spec's are wrong. Surely it should have said .025 degree, meaning from .035 to .085 degrees....

This is just me applying the sniff test, but a tolerance of +/-0.025 deg doesn't smell right. +/-0.25 deg seems fairly tight to me. A tenth of that? No way.

And I wouldn't get worked up about the fact that the tolerance is twice (or even four times) the nominal. The value of the nominal is very subjective based on where it's referenced from. If the nominal was measured off the axle axis it would be 89.94 +/- 0.25 which wouldn't raise any eyebrows.

Still, it seems a little odd to me that they don't mind that much toe out. I'm no expert, but it seems like I've always heard you want neutral to slight toe-in. (And yes, I do get that if the tolerance was less than the nominal that it wouldn't allow toe-out, and I'm tearing my previous argument apart!)

I'll get pictures tomorrow, but I'm running a complete 1995 F350 steering setup. That includes an F350 pitman arm and a tie rod connecting the front spindles.

On the +/-, I'm just going to ask for it to be set to .06 degrees of toe-in. I'm thinking that is the main culprit in this, so I think going with the factory settings will be a good starting point.

[Gary Lewis]

I'll get pictures tomorrow, but I'm running a complete 1995 F350 steering setup. That includes an F350 pitman arm and a tie rod connecting the front spindles.

On the +/-, I'm just going to ask for it to be set to .06 degrees of toe-in. I'm thinking that is the main culprit in this, so I think going with the factory settings will be a good starting point.

Ok, here's a pic of the linkage from the front with the weight on it. The red arrow shows the end of the track bar, and you can see the other end of it attached to the axle. (And the Royal Purple bottle and the paper towels on the floor show my ill-fated attempt to cleaning drain the PS/hydroboost system. )

And here's a shot from the other side.

[Nothing Special]

Ok, here's a pic of the linkage from the front with the weight on it. The red arrow shows the end of the track bar, and you can see the other end of it attached to the axle. (And the Royal Purple bottle and the paper towels on the floor show my ill-fated attempt to cleaning drain the PS/hydroboost system. )

And here's a shot from the other side.

Definitely the one solid tie rod rather than the two angles rods of a TTB steering. So you shouldn't have any of the wander issues Bill was thinking about.

As far as bump steer goes...

If you DIDN'T have the track bar, as the axle moved up it would move pretty much straight up (being controlled by just the leaf springs in that case). In that case the distance between the right knuckle and the steering box would decrease, but since the drag link wouldn't magically shrink it would push the steering off to the right. And as the suspension compressed the truck would tend to veer right (or the steering wheel would move to the left)

Since you do have a track bar which is pretty short and at a pretty steep angle, as the axle moves up it will actually move quite a bit to the right. Moving up would shorten the distance between the right knuckle and steering box, but moving to the right would increase that distance. From the geometry the increase would be greater than the decrease, so since the drag link won't magically stretch either, you should get some bump steer of the truck veering left (or the steering wheel turning to the right) as the axle comes up.

Eyeballing it I'd say you'll have less bump steer with the track bar than you would without. And I don't see a good way to move mounting points to minimize it. So I don't think I'd suggest any changes in this area. But I think you will get some bump steer that you'll have to live with.

For what it's worth, solid axle leaf sprung vehicles never used to have track bars, and when Ford started putting them on F-350s a lot of people thought it was a terrible idea, that it would kill the suspension travel and the ride. I have no personal experience, but I have heard that the track bar was a significant improvement in handling. It must make the suspension stiffer (since the springs have to bend sideways or twist or something to let the axle move over as it moves up). But evidently that's not a huge issue.

[85lebaront2]

Ok, here's a pic of the linkage from the front with the weight on it. The red arrow shows the end of the track bar, and you can see the other end of it attached to the axle. (And the Royal Purple bottle and the paper towels on the floor show my ill-fated attempt to cleaning drain the PS/hydroboost system. )

And here's a shot from the other side.

Ok, as the axle moves up in relation to the frame, (a) the track bar will push the axle to the right and (b) the drag link will push the knuckle out at the front as in a right turn, BUT the track bar being shorter and at a greater angle will move the axle to the right further than the drag link, so the truck will pull to the left. This will be more evident at higher speeds as the tendency to pull to the left will result in the truck tilting slightly toward the right which will result in more downward motion on the right side moving the axle further to the right and giving more of a pull to the left.

Is it possible to lower the inner end of the track bar or raise the outer end so it is closer to parallel to the axle?

[Gary Lewis]

Ok, as the axle moves up in relation to the frame, (a) the track bar will push the axle to the right and (b) the drag link will push the knuckle out at the front as in a right turn, BUT the track bar being shorter and at a greater angle will move the axle to the right further than the drag link, so the truck will pull to the left. This will be more evident at higher speeds as the tendency to pull to the left will result in the truck tilting slightly toward the right which will result in more downward motion on the right side moving the axle further to the right and giving more of a pull to the left.

Is it possible to lower the inner end of the track bar or raise the outer end so it is closer to parallel to the axle?

Thanks guys. But lets see what the truck drives like when I get the toe-in set properly. It may be quite livable at that point. But that won't happen until next week at some point.

[ArdWrknTrk]

Thanks guys. But lets see what the truck drives like when I get the toe-in set properly. It may be quite livable at that point. But that won't happen until next week at some point.

Gary,

Off topic but, why on earth didn't you just put the return line in a jug and start the truck?

You know it's going to pump until* it has no more.

Sure the line up to the booster would drain back, but you're not going to hurt the pump.

It's a core at this point anyhow.

*😖

[Gary Lewis]

Gary,

Off topic but, why on earth didn't you just put the return line in a jug and start the truck?

You know it's going to pump infill it has no more.

Sure the line up to the booster would drain back, but you're not going to hurt the pump.

It's a core at this point anyhow.

I didn't think of that, Jim. But should have!

[ArdWrknTrk]

Gary,

Off topic but, why on earth didn't you just put the return line in a jug and start the truck?

You know it's going to pump infill it has no more.

Sure the line up to the booster would drain back, but you're not going to hurt the pump.

It's a core at this point anyhow.

I didn't think of that, Jim. But should have!

Simple isn't always stupid.

[Andre]

Thanks guys. But lets see what the truck drives like when I get the toe-in set properly. It may be quite livable at that point. But that won't happen until next week at some point.

Gary,

I am with Bill and Bob on this issue, with the suspension going up and down, the axle will be pushed somewhere due to the stiff linkage you have added. Might be worth to install something similar to and shock absorber in the same place, this just to verify if it would change something.

Further more I find your angle from the pitman arm to the main steering shaft steep, sure you dont need to install a pitman arm that come down much more, to reduce the angle of the steering shaft?

Adjusting toe in is an option, zero is the worst, on my Bronco I decided to use some toe out, mainly for being a 4X4, and when that is selected the wheels will be pulled in to much.

Why have you not installed a steering dampener, this could reduce the bump part as well?