4 Link Tech or Four Link Tech

Rokcrler · Dec 12, 2016

Re: Re: 4 Link Tech or Four Link Tech

BUG-E J said:
Honestly on a solid front axle that will not be driven much on the street the best thing to do is get the high steer arms as flat as possible.

Flat arms = zero caster = squirrelly driving and steering especially with the back spacing on the wheels most run. Even crawling it'll push thru turns. 6-8 gives better turning and steering.

kmcminn · Dec 12, 2016

Re: Re: 4 Link Tech or Four Link Tech

Rokcrler said:
Flat arms = zero caster = squirrelly driving and steering especially with the back spacing on the wheels most run. Even crawling it'll push thru turns. 6-8 gives better turning and steering.

What did you set the angle up at on the jeep front?

Rokcrler · Dec 12, 2016

7* if i remember correctly, i'll have to check my notes.
I always shoot for 8, but all that depends on pinion angle also. Yours being a HP made it easier to not have shaft bind and have good caster throughout the cycle.

BUG-E J · Dec 13, 2016

Re: Re: 4 Link Tech or Four Link Tech

Rokcrler said:
Flat arms = zero caster = squirrelly driving and steering especially with the back spacing on the wheels most run. Even crawling it'll push thru turns. 6-8 gives better turning and steering.

A little positive toe fixes squirley steering

kmcminn · Dec 13, 2016

So say you are building you own front axle you would have the front of the steering arm higher by 7 degrees? And have the pinion angle pointed where you want it? What about a rear steer axle?

Rokcrler · Dec 13, 2016

Re: Re: 4 Link Tech or Four Link Tech

kmcminn said:
So say you are building you own front axle you would have the front of the steering arm higher by 7 degrees? And have the pinion angle pointed where you want it? What about a rear steer axle?

If you're rotating the C's, set your pinion angle then set your C's for correct caster.
If you're starting with OEM axle and not rotating the C's, it becomes a compromise, HP axles help and can be swapped from driver to passenger (see what I did to Broady's).
LP tends to have a bad pinion angle especially if you don't push the axle forward.
Yes zero caster works (see whitey) but at speed it is a bit squirrelly but manageable.

kmcminn · Dec 13, 2016

Re: Re: 4 Link Tech or Four Link Tech

Rokcrler said:
If you're rotating the C's, set your pinion angle then set your C's for correct caster.
If you're starting with OEM axle and not rotating the C's, it becomes a compromise, HP axles help and can be swapped from driver to passenger (see what I did to Broady's).
LP tends to have a bad pinion angle especially if you don't push the axle forward.
Yes zero caster works (see whitey) but at speed it is a bit squirrelly but manageable.

So 7 degrees is rotatinv the front axle pinion towards to ground? Just trying to figure out which way the degrees angle goes.

Beerj · Dec 13, 2016

kmcminn said:
So 7 degrees is rotatinv the front axle pinion towards to ground? Just trying to figure out which way the degrees angle goes.

Yes

BUG-E J · Dec 13, 2016

Re: Re: 4 Link Tech or Four Link Tech

kmcminn said:
So 7 degrees is rotatinv the front axle pinion towards to ground? Just trying to figure out which way the degrees angle goes.

Yes.

Bebop · Dec 13, 2016

kmcminn said:
[...] What about a rear steer axle?

Wondering about that too.

I heard 0deg of caster is good for rear steer, but I've also heard to set it up like the front.

mac5005 · Dec 14, 2016

Bebop said:
Wondering about that too.

I heard 0deg of caster is good for rear steer, but I've also heard to set it up like the front.

X3 on this. I'm curious about caster and Ackerman in the rear for rear steer.

Should the king pin inclination be sloped to the rear, parallel to the front axle caster

Or opposite, so that the vehicle center of mass is "jacked" while turning to ensure the return to center?

Here are A couple good links to read about link suspensions.

Have your thinking hat on.

http://www.pirate4x4.com/forum/general-4x4-discussion/2117386-mark-ortiz-chassis-newsletter-anti-effects.html#/topics/2117386?page=1&_k=riscnf

This thread title is to ifs/irs but principles are same for solid axle. They talk about what applies and what doesn't specifically to solid axles later on. This stuff is ahead of tech I have seen from anywhere else.

http://www.pirate4x4.com/forum/general-4x4-discussion/1928282-basic-ifs-irs-anti-squat-dive-tech-twist.html#/topics/1928282?_k=qfilf8

Forbanger · Dec 14, 2016

While I have never ran rear steer, I would assume you would still want positive caster. I'm thinking if you did not than with every bump or movement of the suspension the tires would want to naturally turn all the way to one side or the other. That is why you want positive caster. The more you have the more your tires will want to return to center or track straight. However I have never really had anything with rear steer so I was just assuming.

lowbudgetjunk · Dec 29, 2016

From another thread

mac5005 · Dec 30, 2016

Here is a link to a calculator I did to find spring rates based on preload and using measured values from current springs.

http://metalwerxdesign.com/files/springcalculatorv2.xlsx

Mooretoyx4 · Jan 5, 2017

Back on the topic of pinion angle and caster, what would be ideal angles when building at full bump? My t case flanges are at 0 on the angle finder.

clemsonjeep · Jan 6, 2017

I'd say your caster would probably be in the lower range at full bump. I believe mine was set at 6 at ride height and if I'm thinking right it was around 3 at bump and 9 or so at full droop. I've got 5.5" up travel and 8.5" down travel from ride height for perspective.

Beerj · Jan 6, 2017

If you run your numbers in the calc it will tell you pinion change which is in direct correlation with caster. That would get you pretty damn close I think.