DanStew

Looknig through the writeups both with purchased kits and home brew SAS, i noticed that every kit has a seperate crossmember wqelded to the bottom of the original crossmember on the frame? What is the purpose of this? Couldn't the existing crossmember be strengthened with some plate steel or angle iron and the front mounts weld to that? This would lower the front monuts a touch. I can see there maybe issues with the steering, but is that the only reason? I am really leaning to putting the shackles in the front and use either the RUF or possibly source out some longer springs to get a softer ride. But i like having the shackles in the front and believe it would be a bit easier to setup the SAS that way. I am just looking for the reason why all the SAS setups i have found adds the mount under the existing crossmember?

Elvota

Well, I don't have a definitive answer... but I will tell you that even with a Marlin SAS crossmember welded from end to end under the factory crossmember my frame still started to crack. It cracked right behind the factory cross member, so I had to reinforce this section to keep it from failing.

Like so:



I don't think that part of the frame is really designed to hold all the weight of the vehicle. I think the new SAS span helps a bit laterally, but not in regards to frame attachment.

Also, I think most SAS kits are designed to be bullet proof and easy to install. With a one piece hanger, it's hard to have alignment issues and also gives room for steering components.

As far as shackles in front, it has been done... but I think the ride will actually be rougher. With rear shackles, the axle moves back when you hit bumps... and that's what it wants to do. With front shackles, the axle needs to move forward... into the bump. Front shackles are also more exposed to damage.

Some of this is just thinking out loud, and I'd be happy to hear more arguments for front shackle setup over rear.

Elvota

While trolling around the net, I found a pic of this self made hanger:



Seems to eliminate and beef up the factory crossmember entirely. Would give you the lowest ride height possible as well. Would jjst have to figure out your steering clearances and such.

LTrunner

the only reason for that hanger is cause i's WAAAYY stronger than this

waskillywabbit

iTrader: (-1)

Adding a front spring hanger/crossmember...
1. beefs up the OEM
2. adds lift
3. adds lift for steering clearance
4. moves the front axle forward
5. you can weld it on before cutting off the IFS
6. tried and true method

among other things but these are the most obvious.

My bet is it was weak or cracked before you ever SAS'd it you just never noticed and the extra force to it just amplified it.

That hanger is on a Formula Toy and really not relevant to a SAS since F-toys are setup differently (engine is back 6-8" and down 1").

If it ain't broke, don't fix it.

DanStew

Here is the link to the pros and cons of the reversal.

http://www.jeeptech.com/susp/elkcahs/

When I installed the waggie axles under my jeep i kept it at shackels forward and the ride wasnt so bad. Was stock yota mini trucks shackle forward? And by chance Spring under?

Elvota

I suppose that is possible, but there really isn't any load at that point in the frame with the IFS.

I figured once I put the vehicles weight in front of that weld I really started to stress it. Maybe the 2nd Gens are that much heavier to really start moving things around when on the trail.

I still think starting with a pre-fabbed SAS hanger is the way to go. Just an area of possible weakness to keep an eye on.