I think as long as you have both shackles "live", you have a chance of some side to side motion........however, with your trailing arms set up as you do, it doesn't look like they will allow very much movement. If it wants to wiggle a bit when finally on the road you could add a bar to positively locate it.
Hmmm.... interesting setup. I like it. Panhard bar? Hmmmm... That sucker is pretty burley and the transverse spring will handle a lot of side to side movement. My thoughts are no, you don't need one. Because of the regitity of the links mounted to the axle you've created a solid set-up. I wouldn't worry about it. Do you have a close up of how the links are mounted to the frame? Do you have bushings or something at that end? I hope your set-up isn't TOO rigid. You may find some bind in that. It IS similar to a ladder bar setup for sure. Nice work! Show us more.
One thing you do need is to have another look at your trailing arms. Don't take offence, as your fabrication looks very good...but, your trailing arms are going to bind if you ever go over a bump that is not hit by both tires evenly. Say for example, your drivers side tire hits a bump....there is no way for the drivers side axle to react to that force with out wanting to take the rest of teh rear end with it. Basicly, what you have created is one big ass sway bar that will stress every mount in the system when one tire hits a bump. The best fix for this situation is move the foreward mounting point of your arms closer to the center of the frame. Make your front mounts so that they triangluate close to the drive shaft. That way, thewre is a little "roll" when you hit a bump or go into a corner. Damn nice fab work. -Abone.
PS...To illustrate what I mean...jack the rear frame up and set it on jackstands so you have plenty of clearance to the ground. Next, put a floor jack under the center of the differental. Then, try to lift up just one tire. (say, the drivers) You will see that you can't lift one tire with out binding the hell out of the link on the side you are lifting. That, in turn binds the trailing rod cross member, the pass side trailing arm, the pass mount then the rear end. Sooner, rather than later, you WILL break something in the rear suspension. It looks like you definately have the skill to fix this problem. Make some new trailing arms that mount close to the centerline of the car, and you are golden. Good luck, -Abone.
If you are worried about side to side motion ad a z bar into the set up. My truck is set up this way with air ride. Truck has been together for over a year and no problems. I have put my truck through hell and nothing broke. As long as you welds are strong ,which they look great, you wont have any problems. Look at a truck mag, almost everyone that has bags is set up this way. Just build it and drive it till the wheels fall off.
What he said. Once that's fixed, yes, it needs a panhard bar. Although side to side movement is pretty limited, the rear will still swing all over the place on the shackles.
It was my understanding that unless you move the front of the links inward like was mentioned before, the ridgidity of the rear will have a tendency to steer the car. However, that being said you've done a great job of fabrication.
Yeah, what flamedabone said. Look at the rear suspension for 60 thru 72 Chevy trucks, very similar to what you did. They run the coil springs on the trailing arms, and require a panhard bar. It wouldnt be a bad idea to run one, I would if I was in your shoes.
i thought of doing a similar setup but i couldnt get past the fact that if one of the rear wheel hit a bump it would try to twist the rear or break a mount so i went 4 link Do you need a panhard ? i think you need a 4 link but i still have trouble understanding ladder bars. and if you run a triangulated 4 bar then you dont need a panhard bar BUT if you run a straight 4 link you do need one There was just a good post on suspensions ill try to look it up for ya Bill
Most factory trailing arms are actually 3 sided instead of a fully boxed tube, and are able to twist a little to prevent binding. If you look at the system used on a stock jeep tj (a vehicle that needs a lot of twist when off road) they're arms are 3 sided. When guys replace them with solid ones with no ability to twist, they start lifting a wheel, and many end up tearing the mounts right off the frame. I know that's more extreme than anything your rods gonna do, but it's a good way to illustrate the problem. You do nice work though, and should have no problem fixing it, but if you do introduce some "flex" you'll also want a panhard I think, unless you triangulate.
Thanks for the responses. I'm going to add the panhard to control the side to side. I used a poly bushing up front, but could have used a johnny joint or similiar to gain more "flex" without over engineering the suspension. I think the poly will be OK for the burbs. I guess I could have shown better pics and described my intnetions better. I'm not too concered with twisting this suspension up. My last project was dual trangualed 4 links F/R with air shox. So I'm up to speed on 4 links, but never built anything like the single buggy leaf. Thanks
you could remake your arms with two c-channels welded back to back ][ like the nascar ones. they will flex
Here's what I think you mean Flamedabone.... We are doing this setup on my 48 pontiac.... Not quite done but close... does it look ok...Big Dan... ( sorry bought jumpin in on the thread ) hope the pics come along
Forget what I said earlier. After seeing this you obviously don't need any help from me. I like the 4 link even better than your 2 link. Please do write back later and let us know how the 2 link rides. I'm very interested in this set up.
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