I'm about to make my rear trailing links which will be raised at the frame end with a giant Canadian heim and was wondering what I should use at the axle end. Is the stock style rubber bushing the way to go or should I look into Johnny Joints etc......
Also, since I'm an idiot when it comes to 3 link geometry, any ideas about the length? I was planning on fabbing the mounts so that the length of the arms would be about the same as stock with about 1/2" of adjustment either way. What are the pros/cons of longer arms with or without an A-arm extension? (I'll want to be able to adjust the pinion angle for a CV shaft)

The RTEs come with spacers so you can adjust it, aluminum I think. I would think the standard bushing would be fine if you are using Johnny joints at the frame.

some of the guys here in OZ take the stock arms up in the same plane, make them longer and attach to new mounts fabbed at the outrigger. apparently these rigs seem to climb better.

not to say you coudn't make it better again doing something to the a arm???

puffdragon and agrover could have something to say

i dont understand how the suspension works as far as Antisquat etc......

just starting to understand axles gears etc

cheers, Serg

some of the guys here in OZ take the stock arms up in the same plane, make them longer and attach to new mounts fabbed at the outrigger. apparently these rigs seem to climb better.

not to say you coudn't make it better again doing something to the a arm???

puffdragon and agrover could have something to say

i dont understand how the suspension works as far as Antisquat etc......

just starting to understand axles gears etc

cheers, Serg

Longer arms will give less rear axle steer during articulation. Continuing on the same plane would move the chassis mounts higher, out of harms way. I could be wrong, but my minds eye tells me that anti squat characteristics would be increased slightly which IMO is not necessarily a bad thing, but others may disagree.
This may not be too important to you, but some manufacturers deliberately design a certain amount of roll steer into the front and rear links of softly sprung vehicles large bodied vehicles,to counter the effect of sudden severe cross winds.ie if the crosswind pushes on the left side of the truck, it rolls the body to the right on its suspension slightly.the front and rear control arms on the RHS ,which angle up from the axle to the frame mounts flatten out, slightly lengthening the wheelbase on that side. The left side of the truck is slightly lighter due to roll so the control arm geometry shortens the wheelbase slightly. The net effect is that the truck steers slightly into the wind rather than doing a sudden unexpected lane change,
Bill.

The RTEs come with spacers so you can adjust it, aluminum I think. I would think the standard bushing would be fine if you are using Johnny joints at the frame.

The center-to-center distance of RTE trailing arms is damned near stock,just realigned with a variety of aluminium spacers provided for fine tuning the length in 1/4" increments. If one uses bent rear trailing arms, I see no reason to deviate from the stock frame bushings. By bending the arm, at standard ride attitude (can't exactly say standard ride height on lifted/modded trucks:D ), you're allowing the arm to be neutral in the bushing with regard to articulation, hence, you have the full range of motion of the frame bushing, rather than starting out with it partially compressed at standard ride attitude with stock trailing arms. Everyone I have spokenw ith concerning trailing arms has strongly discouraged me from using heim joints at the frame end as these folks (with far more experience in such things as I) all seem to think that the beenfits do not outweigh the costs.

No, I haven't given this any thought:flipoff2: Thanx for letting me do your lift AFI, I learned a lot about suspension doing that job!

PT

I think we need to understand your goals here. What are you trying to achieve by putting in the heim and moving the frame mount up? How much lift are you running? Is the A frame in the stock location?

As stated, if you just move it up anti-squat and roll steer will increase.

Thanks for the opinions... my reason for wanting to move the mounts up to the side of the frame is just for getting rid of the stock ears hanging down. (and I enjoy the building part of this game) I don't know squat about antisquat or roll centers etc (but would like to learn about vehicle dynamics if you could recommend a book) Anyway, the rig is on a 3" lift with 2" of body lift and cutout fenders, 3-link in front and 35's are most likely as big as I'll go. I just want to end up with a capable all around rig.

OK, then your safest bet is to make them longer in the same line as they are now. This gets the mounts higher without affecting anti-squat and reduces roll steer.

I'm not sure if heims are needed unless you are going to increase travel quite a bit. Realigning the mounts to be square with the links due to the lift should allow for lots of travel. The easiest thing to do is cut the existing arms, sleeve and lengthen. Then make a new mount higher and forward in the same line. Weld it in square to match the lengthened trailing arms. Cheap and easy, just a bit of steel and welding.

OK, then your safest bet is to make them longer in the same line as they are now. This gets the mounts higher without affecting anti-squat and reduces roll steer.

I'm not sure if heims are needed unless you are going to increase travel quite a bit. Realigning the mounts to be square with the links due to the lift should allow for lots of travel. The easiest thing to do is cut the existing arms, sleeve and lengthen. Then make a new mount higher and forward in the same line. Weld it in square to match the lengthened trailing arms. Cheap and easy, just a bit of steel and welding.

Thanks! This approach makes perfect sense to me. I agree that I don't really "need" the heims but I allready have them and the DOM to do the job. (they are the mongo Evolution Heims) Besides, they should look pretty cool under there while I cruise the Sonic :smokin: So, do you think the stock rubber bushings on the axle end would be the way to go for longevity and reduced NVH? I should still have plenty of travel right?

Make sure your links are at least .25 wall. I have managed to bend one of mine and virtually collapse the tubing on the other. I am about to rebuild mine as well. Probably lengthening them and placing them inwards of the frame on a new crossmember I will build. Still working out the exact specs to virtually eliminate all axle steer. Also going from round tube to 2" box, .25" wall minimum. Might go bigger as I'm tired of bending things.

Edit: to actually answer one of your questions, regular bushings will work fine on the axle end. If you triangulate at all you will likely need a heim or johnny joint on the other to allow for some twisting.

I'm planning on using 2"x .25" round DOM and then boxing in with .25 plate at the bend.

Hiems are not necessary at the axle end at all. But they are very easy to work with and will outlast bushings by quite a bit. And, keep in mind that if you are going with 2in tube the cross section of tubing that holds the bushing will not be wide eenough to fit your weld in there on the stock mount. When I went up to 1.75in OD I could not reuse the bushings so I had to go to hiems to fit into the stock axle mount. I could have made the axle mount larger, but instead I went the easy way. All you have to make are the spacers to fit the stock link bracket. Besides, its stronger and prettier. :flipoff2:

Buck, you are my hero! :flipoff2:

Hiems are not necessary at the axle end at all. But they are very easy to work with and will outlast bushings by quite a bit. And, keep in mind that if you are going with 2in tube the cross section of tubing that holds the bushing will not be wide eenough to fit your weld in there on the stock mount. When I went up to 1.75in OD I could not reuse the bushings so I had to go to hiems to fit into the stock axle mount. I could have made the axle mount larger, but instead I went the easy way. All you have to make are the spacers to fit the stock link bracket. Besides, its stronger and prettier. :flipoff2:

I see what you mean about the 2" not working well with the stock bushing diameter. Also, with a heim at the frame end do I even need to mess around with putting a kink in the trailing arm? I see plenty of othe rigs that run straight ones and use them for "axle sliders". Any thoughts on the pros/cons of doing that.

I see what you mean about the 2" not working well with the stock bushing diameter. Also, with a heim at the frame end do I even need to mess around with putting a kink in the trailing arm? I see plenty of othe rigs that run straight ones and use them for "axle sliders". Any thoughts on the pros/cons of doing that.

If you relocate the frame mounts so that the bushings are neutral at standard ride hight, there shouldn't be any issues. The only reason I can see to have bent trailing arms is to achieve the correct gemoetry at the frame bushing.

I see what you mean about the 2" not working well with the stock bushing diameter. Also, with a heim at the frame end do I even need to mess around with putting a kink in the trailing arm? I see plenty of othe rigs that run straight ones and use them for "axle sliders". Any thoughts on the pros/cons of doing that.

This is desirable in my mind, as long as you do as Paul says (not always, but in this case). Definitely want the trailing arm bushing neutral. Ultimately I would rather remove the stock mounting point and redesign it to something a little more durable and out of the way.

This is desirable in my mind, as long as you do as Paul says (not always, but in this case).

Better to do as I say, rather than as I do:flipoff2: