New "Truck Arms"

I'm interested in using a new set of the early Chevy truck arms for for the back of my Buick. In descending price order, I've found the NASCAR arms from stockcarproducts.com, the tubular arms from CPP and just today I found what seems to be the best solution for a new arm at earlyclassic.com.

Are there any other maybe less expensive choices for a new stock type arm?

Thanks,
Eric

 

Go to your steel supplier and get some 2x3 ibeam, drill out the web, put a big rubber/poly bushing up front and an axle mount pad on the other end.

 

I agree. Roll you own. That way you can be sure that they are a perfect fit.

 

Not sure what they cost, but these look nice.

http://www.hotrodstohell.net/truckarm/truckarm_tri_fives/truckarmtri_fives.htm

 

Those earlyclassic.com arms are really nice. Much nicer than a plain ol I-beam.

 

These here are Chevy pickup rear trailing arms that were refitted under a gasser.

 

Thanks, I checked out the hotrods to hell. Once you add the brackets and u-bolts, the Early Classic are still the cheapest.

 

Really?! They just look like a piece of plain ol box tubing to me. I MUCH prefer the look of a drilled I-beam, similar to the drilled originals posted by Oliver Bros...

 

this place sells a whole kit



http://www.hotrodstohell.net/truckarm/truckarm_index.htm

 

So its kind of like a 2 link? or wait, i see the long arms and the leaf springs. is that what is going on here? where is this normally used? what are the advantages of this set up? Never heard of this setup before short of seeing similar stuff on an old truck

 

I've never seen it with leafs (other than above). It's usually used with coils or bags (i'll be using coils). You also need a panhard bar to limit side to side movement. The Buick already has one and I'm hoping to adapt it to the new rear.

 

The setup in my pics are primarly used for aiding in traction, I believe.

 

i'm going to build a set for my RPU, i have some 2-1/2" by 1/8" wall square tubing, i'm going to split it and weld it back together back to back much like the stock truck arms.

 

I plan on running truck arms on my next hot rod frame I build, it was a toss up between them and a torque arm rear suspension, and the truck arms win because of the simplicity of the system and the fairly compact design. It's really popular with the "G-Machine" corner burning crowd as well as generations of NASCAR racers.

Not to hijack this thread, but does anyone know who sells the giant u-bolts and the weld on axle perches?

 

Nothing wrong with I-beam I guess but yes, these really do look better:



I personally don't think a big giant heavy piece of 3x3 beam is really needed to locate the rear axle on a 2200 lb car.

Most probably already know this but the OEM Chevy stuff is actually two pieces of channel welded together. IMO the Hot Rods to Hell stuff is overpriced for what it is and the Early Classic stuff is kinda pricey too.

I'm going to make my own arms out of 1.5x2.5x.120 rectangular tubing and I'm going to use a big uni-ball on the front end. I was going to use a flange to mount to the axle but I might go the u-bolt route now.

 

THIS is the best way posed so far. What so many people seem to not understand, or choose to ignore, is that these arms must be able to twist longitudinally when the body/chassis rolls relative to the rear axle. That's why GM built them as they did. They are very strong in beam, but the back to back C channel (or an " I " beam that is not too thick in section) allows the twist.

The consequence of no twist is to bind the suspension articulation at best, and rip the mounts off the rear axle at worst.

If you doubt this, try making a simple model with a pencil and popsicle sticks or a piece of tubing and strips of metal, hell a soda straw will suffice, holding the 'arms' close together at the front and turning the "axle" as it would in the vehicle. You will see very quickly the need for the 'twist'.

While some of the suppliers make nice looking tubular or square tube arms, it is my belief and contention they do not work properly....they just look good while not doing it.

Ray

 

The U-bolts should be able to be made locally by someone that sells trailer, semi or suspension parts. As for the perch that is up to you to make.

 

Beef Stew, to each his own I suppose. I don't think those arms look bad, but I tend believe the I-beam would also work better.

Hnstray beat me to the punch with the next point I was about to bring up, and another reason why I-beam is often used. 2x3 I-beam is no larger than box tubing and it flexes/twists slightly like the original sandwiched C-channel design. Even moreso when it's drilled. Box tubing resists this motion, forcing the bushings to take all the rotational movement. I guess the bottom line is: there's more than one way to anything... Just use a bigger bushing!

What he said!!

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What's wrong with using the original truck arms?

 

Nothing wrong with originals........IF you can find a good set. In the Midwest (rust belt) where I live, good ones are rare as hen's teeth.


To the poster who asked about axle housing saddles, Stock Car Products have then, nicely made and not too expensive in my opinion. I also bought their truck arm, made similar to GM originals and am very satisfied with the product.

Ray

 

This is exactly why I'm going to use a uni-ball instead of a bushing. Not the perfect solution but IMO better than a rubber or urethane bushing.

 

Thats what fitzee and I did to make HAMBAndy's rear suspension...but we used some 2x4x1/8" that had been tapered already as it was originally intended to be used as front frame rails for some other project.
Worked quite well and looks good with the taper.

 

I had a helluva time finding them myself. I had to go to a industrial truck supply house. they sold stuff for big rigs, and 2 1/2 ton trucks that sort of thing. They had them in stock, everyone else looked at me like I was from mars. they weren't exact replacements but they were close enough to work.

 

Aren't you supposed to put on floating mounts with a leaf/link system?

U-bolts can be sourced through any competant parts house, made by dorman/ motormite.

 

Actual NASCAR truck arms hanging in a NASCAR shop (Hendricks if I remember right)




Rear of a NASCAR car, you will notice in both these pics they are I Beams - If they can't twist, they don't really work properly! My understanding is the NASCAR rule book mandates I-Beam design

 

Any reason why a couple of early Ford axles couldn't be modified to work in this application?

 

Classic performance products has both.

Chris

 

And probably more than adequate for the ammount of suspension travel you'll have on a lightweight hot rod (that is what we're talking about right? We never discussed what you were putting them on...) I'd still feel more comfortable with an arm that "gives" a little bit, but that's just me.

 

I don't know what kinda parts house your going through but you can't find them through:
carquest
autozone
o'reiley's
advanced auto parts
napa auto parts

The stock U-bolts for those arms are HUGE, and rightfully so there is only one per side.

 

Here are some pics of the truck arms that I make for our Nascar late model stock cars. These are based of off stock dimensions, length and size.

laser cut then to the press brake




In the jig fixture