Adjustable rear trailing arms how-to
 

MODS move if needed

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.
Attachment 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.
Attachment 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.
Attachment 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.
Attachment 415967
Attachment 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.
Attachment 415993
Here it is welded up.
Attachment 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.
Attachment 415995
One of the finished top with the joint
Attachment 415997
and the final product
Attachment 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
 

wow man!
very cool write up!
thanks!
how do you figure they compare to the stock ones, weight wise?

Re: Adjustable rear trailing arms how-to
 

I will weigh them tomorow for you and let yo know.

Re: Adjustable rear trailing arms how-to
 

That's sweet man! Great idea!

Re: Adjustable rear trailing arms how-to
 

Very cool and a great way to replace rusted out arms. If you could figure a way to step them and adjust the pinion angle back into spec they would be an awesome alternative to drop block plus arms. The posibilites are really there for this idea. Again.. way cool :metal:

Re: Adjustable rear trailing arms how-to
 

cool, thanks!

Re: Adjustable rear trailing arms how-to
 

Very very nice write up. Thanks! :metal:

Re: Adjustable rear trailing arms how-to
 

I was thinking the same thing.

Re: Adjustable rear trailing arms how-to
 

is there anyway i can bookmard this thread of something

Re: Adjustable rear trailing arms how-to
 

You can subscribe to it through the forum, or you can bookmark it through your browser.

Re: Adjustable rear trailing arms how-to
 

What are you doing for the mounts at the front? I noticed that they were cut from the X-member. Nice work, time to go into production!!!

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
 

the stepping of the arms would be easy, as for the pinion angle, well that is a different matter, where the arms are connected to the crossmember, is where my adjustability will be, but things can always change, if you had a set ride height in mind, you can set you pinion angle and weld them to match that, just a little more time, but not bad.

Re: Adjustable rear trailing arms how-to
 

thanks for the info:thumbs:

Re: Adjustable rear trailing arms how-to
 

Great thread! I may have missed it but what was the actual angle that you used for your pie cut? I would love to build a set of these, although I don't think I would worry about the adjustable end.

Re: Adjustable rear trailing arms how-to
 

Looks good! I have to follow this one..

Re: Adjustable rear trailing arms how-to
 

Iffin I had the equipment and know-how would be making a set for my '67 as well.

How much time & money do you have invested in this? I know the new trailing arms are quite expensive. As far as the adjustable ends where do you find those?

Great write up, thanks for sharing with everyone.

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
 

Any update on the wire guide?

Re: Adjustable rear trailing arms how-to
 

i will do it today, sorry for the delay

Re: Adjustable rear trailing arms how-to
 

Do you have any other pictures of the "on the end of the sleeves i attached some square solid stock in a cross fashin,"?
Maybe a couple of pictures will clear it up for me.


Mick

Re: Adjustable rear trailing arms how-to
 

Looking @ the pics, it seems that he inseted square solid steel into the end of the sq tubing & plug welded it from each side of the tubing to hold it in place.