Thread: Trailing Arm Suspension

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Hi all,
I have a 1929 Essex Coupe with a 350 sbc and th350 trans and an Eaton Positrac out of a 1968 Camaro. Right now I have the rear axle mounted on the original leaf spring suspension, which isn't parallel to anything. The front hangers are at 31.5 inch centers and the rear hangers are at 46.5 inch centers. I get excellent traction with them, but the hangers are pushing 75 years of age and I'm concerned about them giving away on me.

I've put about 10k miles on the setup since I upgraded the car originally and have not had any problems at all. But, I'd like to go to either a 4 bar or trailing arm suspension. I'm leaning toward a trailing arm because of what I've read in the different forums about 4 links and ladder bars being mainly for straightline driving. The trailing arm also seems to be the simplest to fab and install.

Does anyone have any experience fabbing and installing a trailing arm suspension in this type of car?

I'd also welcome any comments, pro or con.

Also are there any sites around that show what the proper geometry for the trailing arm would be.?

I have a plan view of the original suspension at this site.
www.nucwa.com/essexlube.jpg

Thanks ahead of time.
Gary

The car can be seen at www.nucwa.com/page6.html

Yeah, something like that.

Gary

I'm with Richard on the "refurbish" your stock set up idea as long as it does what you want traction and ride quality wise.

The ladder bar idea is pretty cookie cutter in rods..............and I'm not criticizing it by saying that. Pete & Jakes pioneered it in the earyly 70's commercially. www.peteandjakes.com If you go to a rod run and look under any number of early '30's fords, there's about a 40% chance that's what you'll see under there. The key to mounting the ladder bar (usually with coilovers, or pocketed coil springs, but also a Ford transverse leaf spring) is to have the bars "tapering" toward the center of the chassis as they go forward. This allows the rear some compliance from side to side as it rides over irregular surfaces. It's modeled much like the trailing arm suspension on GM trucks of the '60's/'70's, and is what NASCAR chassis employ. You'll also need a panhard bar, or a watts link to maintain lateral location.

The splayed rear springs on your Essex is a Hudson thing. They felt that it gave a more compliant ride (similar logic to the trailing arm discussion above) and was less prone to spring "wrap up". They used that design idea through to their end in the mid '50's.

Bob and Richard,
Thanks for the replies. I know what you're saying "if it ain't broke, don't fix it".
I'll look into getting the original hangers checked out or maybe having some new ones fabbed up.
Thanks again.

Gary

i am with the others in that i would refurbish what you have as it works well for you. no need to spend money for something that, while it would work well, would be a pain to install and setup. if you really want the chevy truck style trailing arm rear suspension, get a copy of stock car products catalog. they have everythiny ou need to swap over to the truck arm suspension. bear in mind you will need to some welding, including on the rear axle housing, and you will need to do some fabricating, adjusting crossmember lengths fabing up gussets, etc. one other thing to bear in mind is that the chevy truck arm suspension really plants the rear tires when you accelerate off a corner, and can cause damamge to the frame rails unless they are properly reinforced, and the chassis properly triangulated. and if you dont get the setup nearly perfect, very small tolerances in settup, your car will become a handfull to drive and you will hate it. the 4 bar suspension is tried and true on street rods, and is good for drag racing, and street driving. you can make it work on a road course, but it is outdated for that kind of racing. if you reall want to change the rear suspension go with the four bar and coil overs as everything is easier to settup, and like i say it does work great on a daily driver. leave the truck arm suspension to the chevy trucks, and the asphalt racers.