My New Front Arms

[colsoncj]

I've thought about that, but have noticed from pics and searching a few things:
1. it leaves the ear of the unpinned arm sticking down at full twist/flex, thus could be a rock grabber. Now I've seen the pics and know it would take some good odds to actually snag it on one, but I also know my luck with snagging items on undercarriages on rocks..
2. Also at full flex and with repeated use you could eventually start to distort the bracket from the unpinned arm wailing around. not a big deal, but something to consider. however if that ear is removed from the arm, nothing to wail around and thus nothing to smack the bracket.

I figure I'd try the hitch pin first (easily done and no harm no foul right?) Then take it from there. If I see it really giving a beating to the bracket then I might consider something like this, and when I get there I 'd already have asked all the pertinent questions in this thread to have an idea on some solutions!

I now also realize (after re-reading) that Spike meant that the removal of the ear wont change the caster angles, like tool was able to achieve by making now arms. (does that make sense)

I swear I'm not trying to be difficult, just trying to learn more about these crusiers.. so different from 4runners. and in a good way!

 

[-Spike-]

I now also realize (after re-reading) that Spike meant that the removal of the ear wont change the caster angles, like tool was able to achieve by making now arms.

Yes, lifting an 80 will put the caster out of spec, so some kind of correction is needed. Tools R Us is at a height that is beyond caster correction bushings and plates, and likes to fool around with stuff like that, so he went nuts.

I run the hitch pin solution for added flex and comfort on trails. The actual added flex is probably less than a inch or two, but it flexes easier, since the arms aren't fighting each other. It makes for a much-improved trail ride, but coupled with my lack of a front sway bar, it makes highway driving a bit unnerving, so I haven't felt the need to cut off the front bushing just yet. I have my stock arms around somewhere, and am thinking of cutting one of those and pairing it with one of my Slee caster-corrected arms to see if I like it or not. I'll have to compare the arm lengths first, of course.

-Spike

 

[colsoncj]

Thanks for all the info!! I really appreciate it.

 

[Tools R Us]

It may be an naive question, but couldnt one just take and cut the front part of a stock arm off to achieve practically the same results?

The answer would be, it depends on your caster correction, probably not. I’m lazy and have spare arms, so if it would have worked on my setup that’s what I would have done.

There are two flex limiters with the 80 setup: First is the width of the arms, narrowness of the axle brackets. As it’s flexed, the compressed arm becomes effectively longer, the drooped arm shorter, so they try to pull the axle sideways. This causes the arms to run into the brackets, the higher the lift, the worse this problem becomes due to arm angle. When the arms hit the brackets, flex is pretty much stopped and big loads are put on the brackets.

See the pic below of arm to bracket contact, if a straight edge were placed on the bracket it would be easier to see that the lower corner of the bracket is significantly flexed.

The second issue is the four bushings, they attempt to split the load, keep the axle to arm angles relatively even side to side. The bushings do flex (they have to for axle flex) and the compressed arm flexes down relative to it’s at rest position, the drooped arm moves up. The higher the lift, the stiffer the bushings the greater the flex spring rate, resistance.

See the bushing pic, the arm angle is significantly changed relative to it’s at rest angle.

The problem with stock arms is the tie-rod to arm clearance. When the rig is lifted and caster is corrected the arm to tie-rod clearance is reduced. In some cases greatly reduced it looks good when sitting in the garage or cruising on the street, but when flexed the arms hit the tie-rod limiting travel and putting huge load on steering components.

Depending on lift/caster setup you maybe able to use the hitch pin mod with stock arms, be sure to check tie-rod clearance with the stock arm side fully stuffed and turn the steering both ways.

When the front bushing part of the arm is removed, it fixes both problems, greatly reducing flex spring rate, but the single bushing side is allowed to move relatively freely in relationship to the axle/tie-rod. The two bushing arm side controls the axle angle, so when it’s compressed, the axle rolls back and on the droop side (single bushing) the arm rotates up into the tie-rod.

Sorry for the long-winded reply just to say that there isn’t enough tie-rod to arm clearance to run it with stock arms. They need to dip down more under the tie-rod, this lowers the ground clearance in this area. I have hit them often, but only hung-up on them once, of course Mr. Shotts was there to video and post it for posterity!

John Shotts (shottscruisers) : photos : Charouleau Gap with the CopperState Cruisers 12/07- powered by SmugMug

 

[colsoncj]

Thanks for the thorough reply! It makes perfect sense, and its appreciated.

 

[got cope?]

I made a quick page with a few pictures of the new arms.

80 Series Arms

Any particular reason you chose to put the single ended arm on the d-side? Curious.

What effect would it have if you switched it? besides the dive and lift would change sides upon braking and acceleration.

And an off the wall ?. What affects on geometry would occur if custom arms were made and mounted on top of the axle housing?
Im considering a setup like this on a Diamond housing in the future. but was wondering how it would work on top of the housing, mainly for ground clearance.

im looking at making custom arms similar to yours but
probably 4-6" longer than stock.

thanks.

 

[concretejungle]

And an off the wall ?. What affects on geometry would occur if custom arms were made and mounted on top of the axle housing?
Im considering a setup like this on a Diamond housing in the future. but was wondering how it would work on top of the housing, mainly for ground clearance.


thanks.

a lot of guys in Australia have done that. Only down side is it requires about 6 inches of lift to give the arms enough room. I had thought about doing that, but then decided i didn't want to lift that high.

 

[got cope?]

a lot of guys in Australia have done that. Only down side is it requires about 6 inches of lift to give the arms enough room. I had thought about doing that, but then decided i didn't want to lift that high.

i did some more searching and saw that, very cool. thanks.

 

[Tools R Us]

Any particular reason you chose to put the single ended arm on the d-side? Curious.

What effect would it have if you switched it? besides the dive and lift would change sides upon braking and acceleration.

Doesn't matter, have had it both ways. It just seems logical to have the larger arm on the side with the diff hanging down and leave the other side with a slightly better approach angle.

And an off the wall ?. What affects on geometry would occur if custom arms were made and mounted on top of the axle housing?
Im considering a setup like this on a Diamond housing in the future. but was wondering how it would work on top of the housing, mainly for ground clearance.

im looking at making custom arms similar to yours but
probably 4-6" longer than stock.

thanks.

Anytime the arms can be made more level with the ground it will be an improvement, so my guess is it would work better with them on top.

 

[Tools R Us]

a lot of guys in Australia have done that. Only down side is it requires about 6 inches of lift to give the arms enough room. I had thought about doing that, but then decided i didn't want to lift that high.

It's true that 6" is the commonly used number for stock arms, but it depends on your setup. The stock arms have a bunch of bulk, big down swoop/bend (that becomes up swoop when flipped) to clear the tie-rod and generally not shaped correctly (sway-bar fitting issue) to be flipped. If your making arms they can be designed to fit better, increasing the compression travel, reducing lift needed.

IIRC these are (were) made by Dobbin Engineering?

 

[concretejungle]

True Tools, if you are making arms. If that were the case, it seems you are 90% from just making a 3 link? no?

If i were "making" arms to put on top of the axle, why not just use straight stock and 3 link it?

 

[millatruse]

Great thread! Nice work on your control arms Tools.

 

[Tools R Us]

True Tools, if you are making arms. If that were the case, it seems you are 90% from just making a 3 link? no?

If i were "making" arms to put on top of the axle, why not just use straight stock and 3 link it?

It's all about personal choice and the comprises that your willing to make. IMHO the tie-rod is exactly where I would want the lower links on a 3 link. On a 3 link setup the caster/axle angle stays close to the same with travel, the tie-rod to axle angle stays the same, the links swing in relationship big time, so lots of clearance is needed.

IMHO there are three choices: 1, Links under the tie-rod, they will need a big bend to clear the tie-rod when drooped/flexed, reducing clearance under them.

2, Run them over the tie-rod, they will still need to be bent, have lots of tie-rod clearance. Most important they will be mounted high on the axle requiring a tall top link tower to get good vertical separation and sway bar mounting will be a problem.

3, IMHO the best way to do it is move the tie-rod to the front and make the links straight with "proper" geometry. This isn't exactly a bolt on setup, lots of design compromises, challenges. Probably the best way to do this is start with a different axle.

Once I realistically looked at the compromises, design challenges and my uses for the rig. I realized that it was most of the way where I wanted it, just want to free up the front some. By retaining the radius arm setup was able to reduce the flex spring rate, allowing more flex and much more comfortable ride with minimal changes to the rig.

 

[Nay]

I agree that you need to go to a hi-steer setup with the tierod out front to really do a good 3-link.

Lots to gain with little pain with Tools' approach here - the arms under axle make good sliders on the 80, so if you take out some bind you have a good compromise.

 

[concretejungle]

didn't think about the tie rod. hmmmm...

 

[Tools R Us]

If your going to build arms, make them strong, this doesn't look fun,,, or cheap!

 

[concretejungle]

Ouch! care to share if we know who's rig that is?

 

[nicholas]

Dang, it took me a second to figure out where the parts were supposed to be. That doesn't look like very thick tubing on the arms.

Anyone know what size tubing Slee uses in their arms? Or if they are solid?

 

[clarkrw3]

V2 of slee's arms are solid...not sure who's arms those are. I hope they aren't slee v1 :

 

[Tools R Us]

Ouch! care to share if we know who's rig that is?

Don't know, found pic. Looks to be home fab arms and other stuff?

Dang, it took me a second to figure out where the parts were supposed to be. That doesn't look like very thick tubing on the arms.

Anyone know what size tubing Slee uses in their arms? Or if they are solid?

V2 of slee's arms are solid...not sure who's arms those are. I hope they aren't slee v1 :

From what I've been told there are at least three versions of Slee arms? The first were Outback/Slee, some had wrist joints at the chassis bushing, don't know who made them? They had some issues, the pic below is of a local, Mud member's arm, will leave it to him to claim it or not.

Second were tubular Slee units, none with the wrist. I haven't heard of any failures.

Third the currant solid machined arms, good luck breaking those heavy units!

Bottom line is if you run welded arms, inspect them often, especially if their the early type.