SOA caster angles? (1 Viewer)

[chicago]

Just wondering what caster angles you guyz are running with your SOA's in a SR configuration.
With my pinion set at 10 deg, and the ball ends at 4 deg the steering arms will BARELY CLEAR the spring pack.
I know that on an FJ60 you can get away with a bit more caster (up to 6 deg), but IIRC you dont wanna do that much on a 40.

Thanks for any input.

Im staring down the barrel at more $$$$ for different steer arms (4x4 labs) which he can "tune" them a bit. Not a bad thing, but not really what I wanted to do either.

 

[71-CRUISER]

I run the 4x4 Labs arms and generally set caster at 4-6* on SOA 40s

 

[rockcod]

SOA and SR, 10* pinion, 5* caster, All Pro Hy-steer arms and GM 1 ton TRE's

 

[chicago]

I run the 4x4 Labs arms and generally set caster at 4-6* on SOA 40s

I thought it was like 1-2 deg for some reason?

SOA and SR, 10* pinion, 5* caster, All Pro Hy-steer arms and GM 1 ton TRE's

How does it handle for you?
Steering twitchy at all?

I should also add that Im using FJ60 springs and axles. Makes a little bit of difference, but I cant imagine that much.

Also, the WB is at 102'

Thanks for the responses.
Please keep em coming!

 

[chicago]

BTW...with your set ups, about how much clearance do you have between the top of the springs and the bottom of the tie rod?

 

[Johnpenner]

Thx for this thread

What is stock caster?
Marlin Crawler sets pinion @ 10 deg. & stock caster, forgot to ask him what that was.
I was thinking about adding 1-2 deg more caster than stock.
SR?? spring reversal? longer wheel base? how does that look? Does it throw the front out there a bunch? I know the rear needs to go back & cutting the body looks great when done right.

 

[Johnpenner]

How about heating them & bending them up a little????

 

[rockcod]

I thought it was like 1-2 deg for some reason?

How does it handle for you?
Steering twitchy at all?

Not twitchy at all, freeway driving is a pleasure, it goes straight as an arrow.

Stock caster is around 1*

Click on my Sully thread all of my info is on there.

 

[71-CRUISER]

The more caster the straighter the truck will want to drive. Like stated above stock is 1* and anything more than 1 and less than 10 is OK.

Im SOA w/ 4x4 labs arms and flipped stock ft springs. The Tie Rod barely rubs my frame on the pass side at full compression and rubs the spring at full drop. I generally set the pinion angle and rotate the caster till the arms look like everything will fit and the caster is between 3-7*.

 

[chicago]

Thx for this thread

What is stock caster?
Marlin Crawler sets pinion @ 10 deg. & stock caster, forgot to ask him what that was.
I was thinking about adding 1-2 deg more caster than stock.
SR?? spring reversal? longer wheel base? how does that look? Does it throw the front out there a bunch? I know the rear needs to go back & cutting the body looks great when done right.

Here are a few pics of my set up and what I did. I cut off ALL the hangers and relocated everything and shot the rear axle back as far as I could get it. I threw in a dual t case set up, so I NEEDED to do this in order to get a usable drive shaft length.
The SR, I wanted to get the springs closer to the frame and more protected from the rocks than you would have with the stock shackle at the front configuration. Because I went with FJ60 springs and axles which are 3 in wider than the FJ40 stuff, I had to outboard the hangers all the way around for the proprer spring width. This will also help with off camber stability when wheeling so its a win win IMO.

 

[chicago]

Few more of the front set up thus far.

 

[chicago]

Here is one with the rear done. Gives an idea of how it looks.
Ill obviously need to do a comp cut to the rear quarter for the tires.
I initially had the WB set at 104.5, but I NEEDED to drop the drive shaft angle to clear my trans pan. Its SOOOOOPER TIGHT. Having a smaller dia. long slip shaft built as we speak.

 

[chicago]

The more caster the straighter the truck will want to drive. Like stated above stock is 1* and anything more than 1 and less than 10 is OK.

Im SOA w/ 4x4 labs arms and flipped stock ft springs. The Tie Rod barely rubs my frame on the pass side at full compression and rubs the spring at full drop. I generally set the pinion angle and rotate the caster till the arms look like everything will fit and the caster is between 3-7*.

This info actually helps me a GREAT DEAL.
When I set the pinion angle and measured the castor at the ends, the PS was dead @ 4*. The DS, however, was @ 2*... From the factory that way. This (of course) was where I started taking clearance measurements from.
I was of the impression that 4* was the max you would wanna go on the 40s. So even 2-3 deg up will help a great deal. Ill try that first and see where it ends up as far as clearance. If I can use my BRAND SPANKING NEW arms that I have I will. Dont wanna pay more if I dont have to.

Thanks for the input!

 

[pbgbottle]

mine is set at 5-6 degrees no issues drives straight

 

[chicago]

mine is set at 5-6 degrees no issues drives straight

Any rub any where with the links?
From the looks of the 4x4 labs set up, it would seem that you would have pleanty of clearance?
Im guessing that is one of the MAJOR advantages to that set up?

 

[chicago]

Still looking for some dimensions on the clearance from ABOVE the spring pack to the bottom of the tie rod if anyone can gimme an idea that would help immensely!

Please.

Bump!

 

[Pin_Head]

The more caster the straighter the truck will want to drive.

No, not really.

All you need is some caster to make it track straight and 1 degree is enough. More caster = more self centering force and higher steering effort.

The most caster I have ever seen on solid axle trucks up to semis is 3 degrees. There is a down side to too much caster, which is excess wear on the sides of the tires and a decreased contact patch is turns, which could be a problem on slick surfaces. Excess caster would not be a problem on a trail only vehicle,

 

[71-CRUISER]

edit: The more caster the more the steering will want to self center.

To much Caster does cause the issues that you mentioned, but as long as it is reasonable you wont ever notice it. The higher steering effort is all relative w/ Saginaw boxes, rams and 36"+ tires.

 

[chicago]

No, not really.

All you need is some caster to make it track straight and 1 degree is enough. More caster = more self centering force and higher steering effort.

The most caster I have ever seen on solid axle trucks up to semis is 3 degrees. There is a down side to too much caster, which is excess wear on the sides of the tires and a decreased contact patch is turns, which could be a problem on slick surfaces. Excess caster would not be a problem on a trail only vehicle,

This will be a streetable rig, but not a DD. The only road time it will see is to an from the trails. With that said, those distances WILL be far in some cases.
How much of a difference will a few deg. make in respect to the handling? Say, if I set the castor at 7 or 8 deg., do you think I will notice it. I realize that this is TOTALLY subjective, but on my FJ62 that i built I set the castor at 5 deg and thought it handled great aside from a slight ANNOYING pull to the PS. Do you think that I would FEEL the additional 2 deg if I were to set it at 7?

Just curious. I know there is the 'ideal" and then there is the practical in this build game.

I should also add that I have never driven this rig. I brought it home not running and tore it apart. So aside from my 62, I have no other experience to compare to.

At the heart of this matter is the funds. I have a set of steer arms that I could MAKE WORK with less than ideal geometry, or I could spend MORE MONEY on a different set of steer arms that may make negligible difference from one to the other. This is why Im asking the questions as I dont know.


thanks for posting up!

 

[rockcod]

Hey Keith,

For what it is worth, I would take the time to save your money and buy the new steering arms and do it right the first time. I have rushed projects in the past, trying to get out on the cheap, only to end up doing it for a second time the way I should have done it in the first place. You know what the parts cost, now you need to figure out what your time is worth and if you want to spend it doing it for a second time.

Just my .02