DIY- Adjustable rear trailing arms
 

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I thought i would give a how-to on this. everyone on here has been very inspirational and helping of others. so here is something from me. I wanted to build adjustable trailing arms for a few reasons. i can alter the wheelbase, alignment is easier, and i added ballistic joints that are teflon lined for uninhibited wheel travel in the rear, there is no compression of a bushing. Well on to the build, if there are questions ask away, i will answer to the best of my knowledge, and please forgive me if i made a mistake.

Anyways, the first thing i did was lay down some white poster board on my bench, i taped it down so it would not move. I then traced out the original trailing arm for the angle and pivot points. once i did this i marked out my tubing i was using (2"x3"x3/16") and found where my new angle will be located.
http://67-72chevytrucks.com/vboard/a...hmentid=415971
Once i marked out what and where my new trailing arms would be i proceeded to find the existing angle of the old trailing arms. i then used this angle to determine the pie cut i would need to kick up the rear of the arms. Sorry i did not show a pic of the angle finder.
http://67-72chevytrucks.com/vboard/a...hmentid=415972
What i did now was to take a rachet tie down and squish the two ends together until my desried anlgle was acheived. Once it was acheived i then tack welded in two spots on the top of the cut so it did not move, do not fully weld up yet. and make sure that the arm is still square.
http://67-72chevytrucks.com/vboard/a...hmentid=415965
i then cut the other arm with the same pie cut. once that is done i used the tie down againg to bring that one together, once it is i used C-clamps to clamp them together to make sure that they were the same angle. once this was done i tack welded the outsides of the arms. Then i removed the clamps and tack welded the inside of the arms, all the while making sure they are straight. once this is done i fully welded them up. at the same time, i made a boxing plate for the end of the arm and welded it in too.
http://67-72chevytrucks.com/vboard/a...hmentid=415967
http://67-72chevytrucks.com/vboard/a...hmentid=415988

Re: Adjustable rear trailing arms how-to
 

Well, i had that end of the arms done for now so on to the other end, because i was using flex joints, i got some DOM tubing threaded to accept my joints, the threads are 1 1/4". the sleeves are 5 inches long. on the end of the sleeves i attached some square solid stock in a cross fashin, this was then welded up to the DOM tubing. i made a plate for the other end of the tubing as well, i cut a hole in it with a hole saw and my drill press. i proceeded to insert the section now into the arm. i drilled four holes in the arm that equates to where the solid stock will be. i left the end of the DOM tubing sticking out 3/16" for welding. i also welded the backside of it, but make sure that you get it square.
http://67-72chevytrucks.com/vboard/a...hmentid=415993
Here it is welded up.
http://67-72chevytrucks.com/vboard/a...hmentid=415994
Now back to the other end. I now needed some extra strength for where the springs and rearend sit. so i cut 2 pieces 3" by 17" in lenght. i then used C- clamps to hold these in place and bend them as needed. they are centered and fully welded all the way around. now all that is left is to drill the holes for the rear differential and spring. the spring hole i am gonna drill a hole on just the top and insert a bushing with threads in it that will be welded to the arm, for the bolt to attach through the top.
http://67-72chevytrucks.com/vboard/a...hmentid=415995
One of the finished top with the joint
http://67-72chevytrucks.com/vboard/a...hmentid=415997
and the final product
http://67-72chevytrucks.com/vboard/a...hmentid=415996

Re: Adjustable rear trailing arms how-to
 

Here is a few more pics also, and a list of materials i used.

LIST:
Two 53.5 inch lengths of 2" x 3" x 3/16" tubing
2 Ballistic Joints
11 gauge sheetmetal
2 two 5 " lengths of DOM tubing

that is it, u can use whatever joints you want to, but this is what i did. and make sure you USE A SUFFICIENT WELDER TO DO THIS.

Anyways, thank you and enjoy

JAMES

Re: Adjustable rear trailing arms how-to
 

Weight wise, i weighed them tonite and they weighed 4 lbs less than the originals, so a savings of 8lbs, although i do not think that is gonna help me much with what i am doing, but every bit counts.

James

Re: Adjustable rear trailing arms how-to
 

The mounts on the front are being made from 3/16th steel plate, check my build up of HAVOC and this will explain more, the frame is no where near original any more, as for production, , there is always a possibility,

Re: Adjustable rear trailing arms how-to
 

hey guys, total investment for the control arems with the end links is about 140 dollars as for time about 6 hours, the adjustable ends are from ballistic fabrication and as for the pie cut, i figured out my angle with an angle finder, what you could do is bend a wire the original bend of the arms and now use it for you bend, but you have to use the other side of it, i am not sure that makes sense, i will try to get a pic of what i mean for tomorow night for you , is that ok.

JAMES

Re: Adjustable rear trailing arms how-to
 

Hey guys sorry for the late response. i will show some pics of what i did, these i took after the fact to show you so bear with me.

As for the angle of the arms, i traced them on white borad. i then took a cheap angle finder and made the same angle that the trailing arms were. once i found this i turned it 90 degrees and that created my angle that i had to cut out to bend my arms too. mathematics is what it is. add and subtract.

for the end piece, you are really gonna have to bear with me, i took my threaded rod and welded square stock to it in a cross fashion ( + ), then drilled coresponding holes in arms to then plug weld the stock too. this creates a stronger area than just welding it to the end.

as for the length i will find out and let you know.
If ther are any more questions just ask.