These guys offer a kit and there's a decent article that shows an install. I'm thinking about going this direction for my 50 Fleetline. The only problem I see is cost. http://nolimit.net/Instructions/trailing_arm_install.pdf
If the links are pointed toward each other so that they would interect around the front u-joint, and the actual ends are close together and far forward in the chassis, then they shouldn't really need to flex at all, right? I've always thought the only potential drawbacks were weight (long, heavy arms) and exhaust clearance?
the arms DO NOT FLEX! to prove the point, you could built the suspension with 2x4 solid bar stock. rubber bushings at the front of the arms, combined with the front of the arms being mounted close together provides the flex. the key is the arms being close together at the front, creating a triangle. it's basically the same principle behind the early ford wishbone suspension. "flexy trucks" are my thing too, i've seen guys build "one links" which are basically a wishbone suspension connected at a single point. for that matter, the ford truck radius arm suspension(which breaks all the rules) works quite well. it's all a matter of having bushings or rod ends at the end of the rod to allow enough flex, whatever the vehicle or suspension. as far as panhard bar vs watts link, there's a lot of roadrace cars, a lot of drag cars, a whole assload of airbagged cars that run the imperfect panhard bar. the difference is minuscule in performance in the vast majority of operating conditions. keep in mind, we are not building perfect cars here, compromises are made. i've put the research into what suspension would be best for my chevy, slammed to the deck on bags, the "perfect" suspension would take up the back seat area on a car as low as mine! compromise time. i settled on the truck arm style two link for a few reasons specific to my application: it's easy to package in a low car. it allows rock crawler like flex and travel, i get well over a foot of lift at 100psi, and can easily change a tire. i want to run some serious power through it, i don't need it to hook like a wheelstander, but more importantly no wheelhop or other problems. overall it works very well in an extremely compromised application.
I understand they work, and understand truck arms can be just as stiff, but that wasn't my argument. The chevy trucks are said to be VERY flexy, which is why this suspension works for them. And as someone stated, NASCAR doesn't have very much suspension travel at all. Does it work? yes. Would I use it? No, I wouldn't ride in anything that was driving on one, except a stock car that I can ruin the company who designed it that way . What would I do instead? Spend 25 bucks on 2 end bushings, and a couple feet of DOM tubing and be glad my suspension can articulate just fine if ever needed to.
Box tubing is not a good idea for this type of suspension. I've built atleast a dozen of suspensions like this. One friend had really weak coilovers on his car while building it. He complained about how much the I beams twisted. I had to explain to him that they are supposed to and that the weak coilovers were allowing the car to rock back and forth too much. He changed to a stiffer coilover and he was OK. To the guys that already have box tubing suspensions like this...try something for me. Unhook your springs/coilovers and shocks. With the frame on jackstands and the rear hanging, try picking up one side. If the other side comes with it the suspension is not working right. It may not be bad with the minimal amount of travel that most hot rods have but with something with travel it could cause breakage quick. Clark BTW here's pics of how I have done this type of suspension. I use 3" I beam and make my own arms. I try to make them as long as possible.
I have a 65 Chevy that has trailing arms, and coil springs, and a 65 gmc that has leaf springs, the story I heard (on a truck forum) was that the GMC could have been ordered with trailing arms as an option, and that the Chevy could have been ordered with leafs as an option, but I have never seen seen one myself, I believe this only pertains to the 60-72 era trucks. Dan
Grant...I've got over a 100,000 miles on my 48 with the trailing arms....no problems. Handles great...not "flexy". Launches nice...no wheelhop. I've built a couple of hot rods that handled like slot cars. Boy they were fun in the curves. I was driving the last car I buit (29 coupe) and the owner said he would of thaught I was in a Porche the way I was driving it. I like this style supension and would take it over a 4 bar any day! I've seen several 4 bar setups fail. Lower arms bent, busted brackets. Clark
The bed should not sway much if the tire pressure is good and you have good bushings in your panhard bar. Dan
If you are thinking of adapting the 67-72 Chevy truck route you can go to ECE http://earlyclassic.com/ You can get all the mounts and bushings and even new arms made out of tube steel. They also have adjustable panhard bars. I cant believe I just cut up and scrapped a perfectly good 68 chassis.
i like your idea about unhooking the suspension and running it through its travel, i wonder what would happen if some of the guys with split front wishbones rolled one tire up on a 4" block and then unhooked one of the bones?
I don't know, but I have seen some of the aftermarket truck parts supplyers selling boxing plates for beefing up the trailing arms, and some selling new "duty" trailing arms too. Dan
the truck arms are ment to flex, the racers will trim of 1/16 to 1/8 off the sides to loosen them up, stock cars have been using these for at least 35 years, hot rodders about 5. tells you something doesnt it.
I don't know, but there is a hotted up semi pro streeted (not as blatant as pro street, till you lift the hood) '68 truck that runs around here with the stock arms and Mickey T's on the back. It has a hotted up Big Block Chevy in it for power, I don't know if he really has to, but he runs it on AV gas (it sounds hot). He takes it to the strip on occasion. The arms look to be stock, but I have never asked if they are repops or not though.
The other "advantage" I see is in the k.i.s.s. (keep it simple stupid) factor. Fewer moving parts,fewer links,fewer welds,fewer bushings equals less chance of failure. On a vehicle being driven on the road, not the track, I'd rather have reliability than adjustability.
Clark-- what do you use for bushings @ the front end of the arms? An does the front mount provide for any adjustability to square the rear axle? I'm really considering this type of setup for my Fleetline... I ran Chassis Engineering's leaf spring kit in my previous 52 Chevy, and I really liked it. (Though pricey, I've said many times it was some of the best money I spent on that car.) In one way I'm leaning to using what I already know... ...But hearing so many people talk about how good truck arm setups handle... Anybody run a sway bar (OK, "anti-roll bar") with truck arms?
Steve @ Hot Rods to Hell's been doin em for years (truck arm suspension). He says the advantages are all the way from ride quality, handling, to drag strip traction. 38 Chevy's to 60's Nova's and everything in between. I believe his shop in Glendale Cal is still going, while he moved his family up north somewhere to further his kid's NASCAR career
I am running a home built truck arm setup on my 55 olds(I copied Clarks style), with firestone 2600s mounted about 12" in front of the rear and it gets lots of lift and rides like a caddy. I will run this setup on anything that I build from now on.
Slide...I've run a lot of different things. I started out using the stock Chevy truck stuff but that way costs a little over $50 for the bushings. Lately I've been using eurethane 4x4 truck spring bushings. They come in packs of atleast 6...enough to do 3 cars and I've gotten them for as cheap as $20. The bushings are two peice and look like an oversized 4 bar bushing. As far as what the stock arms will take..Mikey builds some pretty crazy motors. At one time he had a 430 small block with Nascar heads and all the good stuff (you guess the horsepower) that with 10 inch slicks didn't bend the stock arms. He's detuned the truck now. Clark
Clark- thanks! I've often wondered if anyone made a whompin' big bushed rod end that could be adapted to the front of these to allow a bit of adjustment.
When "experimenting" with this ^^ (when it was legal in Cup), we used a big 'ol spherical end retained by snap rings. Adjustment is done (still) using an eccentric mount. vic
I'm running the truck arm suspension on my A and love it. See my shitty website for some more pics under "Current Projects" http://www.hotroddynamics.com/Current Projects.htm
ive been thinking of doing this to my 56 olds, with a watts link or a wishbone. first gotta get the frt susp done.
The 49 & 50 olds used a very similar set up as the Chev pickup discussed here. The difference was the Olds, used 4 rubber insulators at the connection of the rear end housing and torque arms. I set one up using the Olds arms without the insulators, using U bolts to hold rear axle back in the 60s. I mounted the pivots very close to the center as mounted in the Olds. Jack
Does anyone have any experience in runnng one of these setups with a transverse leaf rear spring, say a '40 rear spring?
We installed a set on an El Camino that we put a 502 crate engine in etc.... A great set up from Hot Rods to Hell. Wil www.sakowskimotors.com
My buddy in NY (Grand Island) has been using the Chevy truck arms since the early 70's in his '34 Fords. Also another in Rochester, NY has been installing his version of the same, but using tubing, for almost as long. They work great.
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