JoshC's SAS #2

[Byrd91]

Kirby is totally right on this one. A 4 link or dual radius arm setup (on solid, not TTB) has bind built into the suspension. A 3 link like redranger posted or JoshC posted (well 1 radius arm and 1 link is basically a 3 link) is ideal because 1 side controls the arc of the axle while the other is just a long for the ride and holding the axle laterally. You get to 2 radius arms or 4 links and stuff one side and droop the other its trying to twist the axle in half = binding = not good flex. 3 link or radius arm then depends on preference and what type of front driveshaft you have...single u-joint goes naturally with 3 link (axle stays parallel with outputshaft) and double cardain or CV goes with radius arm (axle rotates to point at outputshaft).

Yomie, are you going to run with no trac bar? Otherwise whats the advantage of your setup?

 

[FROADER]

You get to 2 radius arms or 4 links and stuff one side and droop the other its trying to twist the axle in half = binding = not good flex.

I'm going to disagree with that. Just an example why.

If a 4 link is set up correctly, there will be no bind.

 

[Byrd91]

Froader, you are right. I went into autocad and played around and in the most common situations (upper link shorter than lower) the path is actually very similar in bump and droop. Still won't be exact, but not nearly as dramatic as what I thought would happen.

 

[Kirby N.]

If the links are paralell and same length, then there is no bind. That is set up correctly. Look at stock jeeps. They are set up correctly. I think the bind is significant because I have seen it in real life situations. Have you ever experienced the difference a wristed arm makes? Also, with Jeep long arm kits- Radius arm style- it is very significant when one upper is left off. There is some bind going on there in a R/A setup. It doesn't take much to limit travel. That is why Trucks with rubber c-bushings instead of Poly ones get significantly more travel...

 

[Kirby N.]

I would say ricks is probably setup correctly. If I paid FST to do it, it would be setup correctly.

On 3 links w/ panards, the upper link must be beefy. There is a buttload of stress on it. Also, the joints are probably better as a johnny joint, hiem or superflex RE joint (or anything with out slop) because I think a poly one would contribute to bad characteristics under hard braking at highway speeds.

 

[redranger4.0]

I would say ricks is probably setup correctly. If I paid FST to do it, it would be setup correctly.

On 3 links w/ panards, the upper link must be beefy. There is a buttload of stress on it. Also, the joints are probably better as a johnny joint, hiem or superflex RE joint (or anything with out slop) because I think a poly one would contribute to bad characteristics under hard braking at highway speeds.

all my links are 2" .25 wall DOM with Flex Joints (similar to superflex joints) on both ends of the links

 

[Byrd91]

Kirby, good point on the parallel links...This usually is mostly a logistics issue, mounting the equal length parallel links on the frame end...though doable obviously. Radius arms are the opposite story as you said, crazy bind built in and remedied by wristing or a single link on one side...if it were me thats what I'd do (radius arm on one side) for 3 reasons....less joists, less mounting issues, and my TTB already has a double cardain d-shaft.

 

[redranger4.0]

Froader, you are right. I went into autocad and played around and in the most common situations (upper link shorter than lower) the path is actually very similar in bump and droop. Still won't be exact, but not nearly as dramatic as what I thought would happen.

another thing to consider is that in that pic you gave both the "axle and frame" end alot of seperation, which is going to change how it behaves

 

[Byrd91]

Very true, you get the frame ends of the links closer together and it'll go to crap quick as it approaches being in affect a radius arm.

 

[JoshC]

Alot of good info in here guys, thanks alot!! I've been gone for a couple of days so i couldn't get on.

Three link is what i want. I met a guy down the road from me that is a retired welder and he has absolutly everything thing in his garage and he said he'd do anything i needed! He TIG welded my tree stand for me thursday, some of the aluminum welds were cracking. So, if i can find out for sure if the axle tubes are DOM then i'll be in the garage cutting off the wedges.

 

[redranger4.0]

Alot of good info in here guys, thanks alot!! I've been gone for a couple of days so i couldn't get on.

Three link is what i want. I met a guy down the road from me that is a retired welder and he has absolutly everything thing in his garage and he said he'd do anything i needed! He TIG welded my tree stand for me thursday, some of the aluminum welds were cracking. So, if i can find out for sure if the axle tubes are DOM then i'll be in the garage cutting off the wedges.

why does it matter if they are DOM?

 

[JoshC]

Well it doesn't really, i'd just prefer they weren't cast.

 

[redranger4.0]

All the tubes are going to be DOM, its only like a small section on certain Ford D44's that have a cast peice in them.

thats the cast peice cut inhalf and off the axle tube

 

[Kirby N.]

Ummm, yeah you should have asked if they were cast not if they are DOM. They are definately not cast. Pieces on the axle are- "c"s, knuckles, center section etc. But the axle tubes are not cast.

 

[JoshC]

Finally got off my rear and ordered a set of gears for the 44. I've got everything to rebuild it once i get the gears in.

Explorer is in the garage and ready to start pulling the D30 out. I've gotta do something for a stand for the front end. I think i'm going to go off the front of frame under my bumper so i'll not have anything in the sway when i'm working the suspension and tranny cross member, how does that sound?

 

[redranger4.0]

Ummm, yeah you should have asked if they were cast not if they are DOM. They are definately not cast. Pieces on the axle are- "c"s, knuckles, center section etc. But the axle tubes are not cast.

this depends on what year 44 he has if its a 78-79 then it has the cast section if its a 77 then i doenst

 

[JoshC]

78 i believe. Would a picture of the C's help clarify anything or do they all look the same?

 

[Stic-o]

You can tell by the u-joint.

'78 uses 1310 joint
'79 uses 1330 joint

or so I have heard

 

[JoshC]

What's the difference in the ujoints?

 

[Stic-o]

What's the difference in the ujoints?

1310 and 1330 use same cap size( 1 1/16") However 1310 is 3 7/32" (or 3 1/4") wide and 1330 is 3 5/8" wide

Then you got 1350 which is the same size as a 1330 but with bigger caps.