Upper tri-link build

[Kaczman]

why would that be? no trackbar, steering should remain pretty much spot on, no?

Think of it this way:

1. the wishbone can only travel up and down.
2. the draglink will travel in an arc as it moves up and down
3. since there is no way for the draglink to extend and compress, and no way for the axle to shift side to side the only thing that can happen is bumpsteer.

I've never regretted full hydro. I'm dumb and have had it up to 75 MPH and loved it.


Terry- turn the joint 90* now. It easier to fix in the shop.

-Jon

 

[Weasel]

Think of it this way:

1. the wishbone can only travel up and down.
2. the draglink will travel in an arc as it moves up and down
3. since there is no way for the draglink to extend and compress, and no way for the axle to shift side to side the only thing that can happen is bumpsteer.

I've never regretted full hydro. I'm dumb and have had it up to 75 MPH and loved it.

-Jon

Yeah I thought of that later...I've been running ragged this week and have not been thinking straight.

 

[87xjco]

Well I didn't change the joint orientation, I consider this a prototype arm that may not work at all. If there is a 2nd generation, i'll change that.

Just did my first test drive today, it drove pretty well until I hit a series of bumps at about 30mph, then I had pretty severe death wobble.

The toe hasn't been set though, maybe that will help.

I do notice the body rolls a little when I quickly turn the steering at a stop, more so than before.

So I still don't know, I need to get it aligned and do some more driving before I decide if I'm gonna keep it.

 

[David Taylor]

What is your caster ? It looks more than a little off.

 

[vetteboy]

What is your caster ? It looks more than a little off.

Good point - from this pic it looks like it's tilted even a little bit forward:

You definitely don't want that...crappy caster angle is a prime contributor to death wobble, and bad steering feel in general.

Have you cut/turned the knuckles on this axle at all?

 

[87xjco]

Yeah it must be the picture.

The pinion angle is 7 degrees and the knuckles were rotated to 5.5 degrees positive caster

That build is in this thread. But the alignment hasn't been checked yet. I'll see how close it comes out to what I measured when I set it.

 

[hellbilly04]

Do you mean 5.5 deg neg caster? hope so cause it should be rearward tiping caster on the knuckle & your looks like it's tiping forward.

Yeah it must be the picture.

The pinion angle is 7 degrees and the knuckles were rotated to 5.5 degrees positive caster

That build is in this thread. But the alignment hasn't been checked yet. I'll see how close it comes out to what I measured when I set it.

 

[87xjco]

You had me confused there for a minute

Positive caster = top ball joint tilted back from the lower ball joint

Maybe this picture shows the angle in relation to the pinion better

 

[asp]

i just read this thread and thought it was neat. wondering how in panned out.

about the loading of the center joint- i think the builder wanted it oriented that way for better flex, but i see how it's not designed to be loaded that much front to back. either way, cool stuff.

 

[MoparManiac]

You posted in the guy's build thread about how he crashed it...

http://www.naxja.org/forum/showthread.php?t=69712&page=23

 

[asp]

ooh... i didn't realize this was the same one :doh:

 

[xjbubba]

I'd think that a track bar and a wishbone type front link would not be compatible. The same issue exists with trackbar/wishbone geometry as it does with the steering; when the body compresses/extends, the track bar will cause the body to shift left/right, while the wishbone tries to keep the axle centered. with the steering, the steering wheel involuntarily turns to adjust for the bad geometry. With the track bar, there's no relief.