Cracks me up this thread has one star rating./ Maybe the jackasses want another " name their kids after cars thread again ". Amazing.
on a RAT ROD I once built I used front locating arms from an early bronco on the rear 9" out of the same bronco. Those Forged Ford arms actually looked pretty good after I drilled them. Talk about traction! Like I said, I did it on a Rat. Not traditional by any means. However, you may want to take a look at an '61 or so Chevy 2wd 1/2ton rear suspension. Tuff as nails.
That's how the aftermarket/NASCAR arms are made. BTW I thought about the little kick up section when I was designing my arms and I decided it was more hassle than necessary. I made my arms straight and then made up some 3/8" flanges that I welded to the rear axle. Then I split my arms up the middle and added a big long 3/8" thick flange to them and then put a 1/4" plate on each side to attach to the flange on the axle. The key to the whole design was getting the arms to stay under the floor when the rear suspension is fully aired out. When it's all said and done I'll cap off the front and back with some 1.5" wide strap and it'll kinda have a '36 rear wishbone look to it. BTW I can have one side of the axle tucked up in the c-notch and the other side touching the ground when I have the frame on jack stands and a foot in the air. NO BIND.
Beef Stew.....thanks for posting the pics... I do apologize for my comments that you found upsetting Sunday morning. I can understand how they could have been abrasive. If you will accept a compliment from me.................nicely done! Ray
Nice group of pictures so lets expand on this, Question to Beef stew since you used the pictures fabricated truck arms as an example why did you construct your arms out of rectangular tube which is just the opposite design? I'm not saying it wont work its just an odd method. One of the biggest problems with truck arm design and mounting is that it is difficult to square the rear end. My question is how are you going to determine the square of the rear axle to the frame with out using an accurate jig in construction. No where do most of these hand built truck arms have anyway to adjust the rear axle to square. A race car has a built in eccentric that allows the rear axle arms to be adjusted. It seems like every builder here just uses fixed front mounts. Is everyone relying on a tape measure accuracy measurement , what happens when the rear is found to be 1/4" out of square how do you fix it or is close enough good enough?
Very good question about alignment provisions. I have been intending to use a taut center line string on the chassis and plumb bobs on the axle housing ends and triangulate to a point near(er) the front of the car to square the housing with the chassis before bolting or welding the front mounts in place. I can imagine various ways of making that mount adjustable, but if it is accurate at the outset, that should be sufficient unless something changes, should it not? Ray
very good question dick brought up ,i've seen clark build his set-up, looks & works good but no adustement just like chevy ,i have 3 tapes in the shop that all measure a little different, sometimes close is not that good when tring to square something.
Dick, I think the factory trucks used shims at the front mount where it bolted to the crossmember. If not that is one simbple way to do it. If you built it and got all done and you are a 1/4" out of square you better start over and use a tape measure this time. The trailing arms must be I beams....anything else compromises the suspension. For those questioning the validity of a truck arm style rear suspension, let's not forget that in principle it is exactly the same as the tried and true and generally accepted pretty damn good Pete and Jakes / SoCal ladder bar setup that you find underneath most hot rods. I built a truck arm equipped 48 chevy pick up that to this day is still the best riding truck I have ever owned. My roadster was ladder bar equipped until I went 3 link and it rode and handled excellent. The only downside is the very limited adjustability and relatively high unsprung weight. In an average cruiser that sees a spirited romp here and there, neither of those are really major issues. I hae used factory trailing arms when available as well as the Hot Rods To Hell arms. I prefer the factory arms when when available.
Thank you Sir. Obviously the tried and trued method is with beam but after I spent a lot of time looking at what I was trying to accomplish I found that rectangular tubing would just straight up be easier to use. I also confirmed with some suspension folks that the rectangular tube was okay to use in this particular application and because of the big uniballs being used they all thought that it would be. I knew I wanted to run the big uniball in front and I wanted the bars to be flat. The uniball cups are 2.625" in diameter so I hole sawed the front end of the bars and the cups welded in nicely. And as you can see in the back, I just sliced the bars vertically on a mill and I had some flanges water jetted from some AutoCAD drawings I made up. All in all it all came together well. I was elated when I put it all together and started testing it to find that there was zero bind and tons of travel... more travel than I'll ever need or be able to use once I put shocks on there that only have 5" of total travel. As for the initial install, I spent hours setting up the rear axle in the car and measuring for squareness. What you can't see in the pics is that I did actually have the frame on a jig. Nothing fancy but it was jigged. I measured from the top of the bearing flange on the ends of the axle to a center point on the front crossmember in a triangular fashion and then measured from the ends of the axle to the front axle centerline (wheelbase). Once both wheelbase measurements and both diagonal mesaurements were the same I knew I was center and squared. I used huge clamps to hold the axle up against the frame inside the c-notch. Oh, and I also set the pinion angle during all this too. Once everything was perfect (perfect is within a 1/16" for me) I welded it all up. After that I rechecked everything to find that I was still within my tolerance.
Some more pics of the process: Notice how close together the front mounts are. This was important to make this setup work.
What matters is that you've validated that you've got appropriate bump/droop travel without stressing the arms, and it sounds like you've done that. How long are those arms?
Wow thats nice. So you used 2x3 tubing 1/8" wall? I am still trying to figure if this is the way to go or an I beam. I was looking at the nascar arms that can be had pretty cheap, but my arms can be made about 60" I think. The nascar arms are 51" that I have seen. I am wondering if the extra few inches will give me a better ride and ? Thanks every one for helping me understand this better
First off, Let's all get comfortable.... Truck arms,,, So simple but so complicated... The pics of the fabricated truck arms are some I posted a while back. http://www.jalopyjournal.com/forum/showthread.php?t=451597&page=2 post # 32 I have built these parts and cars for near 20 years. As far as how to build in a factor of squaring the rear in the car. Here's how its done in the stock car world. There are times that it is an advantage to "pull ahead" or "trail" the rear on the right side. Here is a pic of the right side brackets. and the insert to move the rear. They are available in 1/16" increments. Up to a 1/2". But if you need a 1/2 shim to get your car square, you need a better tape measure or one less PBR. This is a right side mount under a racecar. And the left side. The stagger in the height of the arms is to produce rear steer in a left turn only application. Here's a pic of a crossmember I made for an up coming pick-up build that I'm doing. Ride height and forward bite requirements are the reason for so many options. Also the reason for the side angle in the brackets is that when you hold the truck arm to the rear saddle with a u-bolt it makes the truck arm tip to the outside of the vehicle as shown. Here are some pics of truck arm saddles. (the part welded to the axle tube) Fabricated Billet steel The other thing that many don't realize is that you made need to shim the truck arm to reduce or eliminate bind in travel. (rough ride) As far as material to build them or style (I-beam or rectangle tubing) That can be put in the same category of there is many paths thru the woods. It all depends on your application or need. Yes, they flex. Mono-balls work fine if maintained. Rubber is less maintenance but You'd better have your brackets/ holes and lengths in order. As the saying goes "there's no free lunch". To use these properly, have as much info as necessary to install them correctly. I guess I'll also throw my hat in the ring and offer up any help with your questions on your application. Hope this helps...
WOW! Thanks! Question: the first sentence below the last pic....what/where misalignment are you referring to for this correction? Ray
There are tapered shims made to go between the truck arm and the pad on the rear. If ride height or pinion angle needs to be adjusted. This is a 1" straight lowering block or shim. They make them in half degree increments.
I don't think GM used any shims... I've never seen any on the scores (literally) that I've worked on. It's just a bracket riveted to the crossmember. I'm guessing GM did a "it's square enough for mass production" approach. On my truck with those arms, I did use shims to fine tune the final axle centerline... truck is very lowered, so the axle centerline moves forward as the arms swing up in their arc.
I have a 72 truck chassis in my garage without the body or box on it. If you guys want Ill snap a couple of pics, just let me know what you want to see.
I bought mine from Stock Car Products, VA or W.VA i think..........I am not at my shop to get their specific address, but a google search should turn up something on them. I'll post the info later.......but it'll be an hour or two. I bought arms, saddles and the rubber bushings for the front anchor point....nicely made components. Ray
OK, for truck arm products, try this: www.stockcarproducts.com That will (should) take you to Carl's Racing Products.....home page...go down left column, near bottom, click on "rear suspension"....next page, right column, click on "truck arms and components". There may be many other sources, this is just one I am aware of, and these are the arms I purchased a while back. Ray UPDATE: another post went on here at the same time as mine. It said Stock Car Products is out of business. That post has since been deleted. So, I called Carl's Racing Products (804-368-8761)to see what was up, since his website has truck arms listed. Carl confirmed the demise of SCP and told me he does not currently have any on the shelf but is negotiating with a supplier and expects he will have some in a few weeks.. The post below offers additional info on this. I did not ask about Carl's source and I am not advocating anything or anyone in this post. Just trying to provide useful info. But "it is getting curiouser and curioser" [/COLOR][/COLOR]
Hnstray That deleted post was mine. I was concerned about getting some our favorite fabricators in hot water - didn't want to speak out of school, so to speak. I had forgotten about the Stock Car Products / Carl connection. Carl's is a good, solid buisness, they really know race cars and are easy to deal with. He sells race car parts and House of Fab handles the hot rod world. You can get your parts from wherever you choose. Sorry for any confusion.
well I would rather support a hamb member. especially when he is offering up what seems to be an extensive knowledge on the subject. I checked house of fabs site ,but didn't see much for sale. Maybe I will try pm
Another great thread on the HAMB! Pics and info will come in handy for two builds I've got coming up. I kinda like the idea of getting the channels bent at a sheet metal shop as opposed to splitting tubing down the center, and I guess just ordering up a used set of "real deal" Nascar arms would be easiest of all! Thanks to all that contributed to this hot topic!!!
so i was thinking today about how to make the angles back by the dif. and i think i have come up with a plan, sence i'm going to be starting with 1/8"X3"X3" tube i can bend the angles first before i split my tube, its going to be alot easier to bend the full tube as opposed to bending two c-chanels welded back to back, i also think i can make up some simple tooling to form a bead for the U-bolts.
Is like to see that also. With my experience, If I were to use tube I would Split it, v cut and weld the angle and use a piece of hollow round bar, for the ubolt.
One comment for you guys who intend to split a square/rectangle tube....do not be surprised if the pieces "bow" or warp as you slice them. Not an insurmountable problem if it occurs, just an annoying complication to correct. That is one additional reason why having the pieces bent from flat stock in a brake is more appealing to me. And I agree with 31Vickie with a hemi, I would not try to bend the square tube, but just saw a V notch, bend and weld. Same for fabricating from flat stock. Ray
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