Stepped trailing arms

[fixit-p]

I've searched all over and cant find any threads of anyone doing any trailing arms with a 2" step I've seen the adjustable, notched, boxed, blocked and the stock copies. So here I go... I've reverse engineered a set of stock arms and built in a 2" step and pinion correction for a 3" drop spring total 5" drop the miter cuts are all going to be beveled and welded with 7 ga. backer strips and doubler plates on both sides also 7 ga. One problem I'm running into is the mounting hole for the coil spring is rather close to the step and since my c20 has leaf springs I have no idea of the springs O.D. I'm planning on moving the front pivot 1" father since these wheels aren't centered any way and it would help with my spring clearance. Any feedback would be greatly appreciated.

[Spray-Bomb]

Cool Idea

[SCOTI]

Originally Posted by fixit-p

I've searched all over and cant find any threads of anyone doing any trailing arms with a 2" step I've seen the adjustable, notched, boxed, blocked and the stock copies. So here I go... I've reverse engineered a set of stock arms and built in a 2" step and pinion correction for a 3" drop spring total 5" drop the miter cuts are all going to be beveled and welded with 7 ga. backer strips and doubler plates on both sides also 7 ga. One problem I'm running into is the mounting hole for the coil spring is rather close to the step and since my c20 has leaf springs I have no idea of the springs O.D. I'm planning on moving the front pivot 1" father since these wheels aren't centered any way and it would help with my spring clearance. Any feedback would be greatly appreciated.

I've spoken w/one of our vendors about a very similar idea a while back (@ least 2-wks now..... ). We were discussing the current options for truck arms & I questioned why the heck can't the drop be built into the arms vs. having to purchase the arms & then stack a block on top of it.

Nice work! As for spring clearance, couldn't you 'trim' the upper portion a little more vs. it being square? If it was kicked back @ say 45° you'd gain a bunch of room from the looks of it. That would allow for more wiggle room should it be required, or.... switch to air bags .

[fixit-p]

Thanks guys. Scoti I did toy around with various configurations and angled the riser piece but the limiting factor there was the first hole for the axle seat is only about 7/8" from the inside corner to centerline of hole. I've got room for a 6" dia spring if I extend the arm 1" forward I'll have room for an 8" dia spring or like you said bagg it

[SCOTI]

Originally Posted by fixit-p

Thanks guys. Scoti I did toy around with various configurations and angled the riser piece but the limiting factor there was the first hole for the axle seat is only about 7/8" from the inside corner to centerline of hole. I've got room for a 6" dia spring if I extend the arm 1" forward I'll have room for an 8" dia spring or like you said bagg it

The 6" air spring diameter is the recommended size but the larger 7" diameter springs will also work. Since clearance is the concern here, the 6's sound like your best bet. Slam Specialties RE-6's are said to baloon less vs. Firestones if even the 6" diameter is cutting it close.

[LUV2XCLR8]

Originally Posted by SCOTI

I've spoken w/one of our vendors about a very similar idea a while back (@ least 2-wks now..... ). We were discussing the current options for truck arms & I questioned why the heck can't the drop be built into the arms vs. having to purchase the arms & then stack a block on top of it.

I'm still waiting for a set

and

Member fixit-p

[fixit-p]

Originally Posted by LUV2XCLR8

Member fixit-p

Thanks Yo...Well I finally had some time to put my arms together today here's what they look like so far.

[LUV2XCLR8]

Originally Posted by fixit-p

Thanks Yo...Well I finally had some time to put my arms together today here's what they look like so far.

I likey

[70k52wd]

Those are sweet. I have to use my new 69 dollar blocks for a while before I can justify getting these from you.

[gringoloco]

Originally Posted by fixit-p

...here's what they look like so far...

Cool. What else do you have planned? Some speed holes would look sweet running the length of them. Also, are you using inserts on the u-bolt holes? If you're using bags, a circle plate welded in place would be good. Super nice work!

[fixit-p]

Thanks guys I appreciate all the feed back, the feed back early on helped with the final overall look.

The holes for the U bolts are sleeved, I only welded the bottom side the top of the sleeve is compressed against the inside of the top of the tube. I left the tails of the arms long so I could intergrate a custom panhard bar and shock mounts. Speed holes are in the plans but I'm going to line them with some thin wall DOM to give it a solid look thats why I blended the front cap that way (not that anyone will see it once it's on the truck) Now I need to find some 1/2 ton components to bring it all together. Here are some more pics of the process.

[N2TRUX]

Cool piece. I agree with Scoti about more angle on the corners. It may not help the clearance issue but will look aesthetically better.

Then again, so would some cool holes along the length.

[fixit-p]

Thanks for the feedback I played around some more with angling the riser and its doable I would strap the bottom and just cap the top. I agree holes would look good I seen the ones bentfab built (those look amazing) too bad you cant dimple box tubing I thought about boring holes and lining them with some thin wall DOM or simply build them out of flat sheet cut outs which would be the best way. Here's a pic of the angled concept.

[royo]

cool i like it

[SCOTI]

Option #2 'looks' better (flows better). Option #1 works good enough if it's all you can do for extra clearance @ each area of concern (spring OD & rear-end mounting pad).

Since you have one readily available, I've been trying to find the length of these arms w/o having to pull my rolling chassis apart to do so. If you wouldn't mind, what's the exact length from the C/L of the front bushing to the C/L between the u-bolt holes?

[fixit-p]

Originally Posted by SCOTI

Option #2 'looks' better (flows better). Option #1 works good enough if it's all you can do for extra clearance @ each area of concern (spring OD & rear-end mounting pad).

Since you have one readily available, I've been trying to find the length of these arms w/o having to pull my rolling chassis apart to do so. If you wouldn't mind, what's the exact length from the C/L of the front bushing to the C/L between the u-bolt holes?

Yeah I like # 2 better as well # 1 is what it started out as and it evolved into # 2. I like to draw everything out to scale then I can copy and tweak to see what looks better.

The dimensions I took from the stock arms are from CL of front mount to where the arm slops up is 45-3/8" from that point to CL of the first U bolt hole is 4" and the U bolt CL to CL is 4-1/4"

[nuke1]

i like the idea, makes me think again

[N2TRUX]

I'll take door #2 Monte...

[fixit-p]

Door # 2 it is...

[SCOTI]

Originally Posted by fixit-p

Door # 2 it is...

Ohooooo . . .... ding, ding, ding, ding.... ding....

[Hard Luck]

Another thought for the springs is look to the cars of this era (which is where GM got the idea in the first place) On the cars the spring is placed on top of the axle. Play with placement of the top mounting bracket for the ride height you are looking for.

[SCOTI]

Originally Posted by Hard Luck

Another thought for the springs is look to the cars of this era (which is where GM got the idea in the first place) On the cars the spring is placed on top of the axle. Play with placement of the top mounting bracket for the ride height you are looking for.

Unfortunately that doesn't help w/the amount of drop which is what everyone is usually after.

[N2TRUX]

Much more pleasing to the eye...

[Hart_Rod]

Originally Posted by N2TRUX

Much more pleasing to the eye...

Agree............

[fixit-p]

Yeah my first car in high school was a 66 Buick Special it had trailing arms don't remember where the spring were but I did all I could to jack that rear end up to clear my tires was lots of fun.