Gasser "REAR" suspension question.

[oldblueoval]

Greetings all. In the planning stages of a 64 Falcon gasser build. I see lots of posts and info on front suspension but what about the rear. Right now I am looking at moving the spring perches to the top of the axle and ladder bars while keeping the stock springs. Or should I keep the spring mounts where they are and get a higher arch heavier rated set of springs with the ladder bars. Trying to stay with leaf spring in the rear. Front is gonna be the trusty Speedway kit. Thanks in advance![

 

[Old Iron]

You can put the springs on top of the axle with no problem.

 

[bob w]

If you're going to use ladder bars with leaf springs you should use "sliders' or else the rear suspension will be in a bind situation. Google "leaf spring sliders" for a wealth of information.
If the front suspension raises the car quite a bit then move the springs to the top of the axle. Gassers of old generally didn't sit high in front, they sat high all around.

 

[Blue Eyed Devil]

In regards to the front axle - Avoid Speedway junk! Nothing "trusty" about it. Seen way too many horror stories to trust my life and others on the road or track to one.

Check out Bill over at waccustoms.com. He makes a KILLER product right here in the USA (Torrington, CT) and he stands behind his work. You won't get a stronger or more well made product, plus you will be supporting a American small business.

Yeah, they perform...

 

[oldblueoval]

Thanks to all. Blue, I have not heard any bad reports on the Speedway stuff, but, I cant say I have heard any good either. Wondered about the difference in length between the leaf spring pivot point and the ladder bar mount. Gonna try and do an actual build thread on this one. The other issue is power plant, 347 stroker ( price ) or build a 351? Thanks again, keep the input coming![

 

[Skip]

Thanks to all. Blue, I have not heard any bad reports on the Speedway stuff, but, I cant say I have heard any good either. Wondered about the difference in length between the leaf spring pivot point and the ladder bar mount. Gonna try and do an actual build thread on this one. The other issue is power plant, 347 stroker ( price ) or build a 351? Thanks again, keep the input coming![

Which 351 do you plan on using? I have a couple of Cleveland 4Vs. One in my Cougar. That makes sense. Its a breather and designed to travel all day at high speed. Think NASCAR. The other is in an altered chassis that I picked up a year or so ago. I don't see it as a good choice in this application. My Cougar is a dog out of the hole. Not exactly what we want in a gasser.

Have fun.

 

[Bamamav]

If you're going to use ladder bars with leaf springs you should use "sliders' or else the rear suspension will be in a bind situation. Google "leaf spring sliders" for a wealth of information.
If the front suspension raises the car quite a bit then move the springs to the top of the axle. Gassers of old generally didn't sit high in front, they sat high all around.

Another way of doing it is to take a section of tubing that will just fit over the axle tube, split it, put it around the axle tube and weld it back together. Make sure it will spin on the housing. Then, weld that to a spring mount pad and bolt the springs up to the pad like normal. This will allow the axle to rotate when it goes up and down in it's travel, the ladder bar mounts, which are solid on both ends, keep it from moving in anything but an up and down plane. You might need a panhard bar to control side to side movement, or you could put a stop rail on both sides of the axle tube spring pad mount to keep it from sliding back and forth on the axle.

I have seen kits for this type spring mount with rollers that fit against the axle, they could easily be copied if you don't like the idea of the tube rubbing the axle housing.

 

[oldblueoval]

Thanks Bama! That is a slick idea. allowing two different arcs for the two different lengths. Looks like I will be going with a 302/C-4 combo. Got a 1971 302/ C-4 out of a Torino/Fairlane. All original components, never opened up and very little wear. Plus-FREE![

 

[Bamamav]

You're welcome! It allows the suspension to work without binding. Old school tech used before ladder bars became popular, or where they weren't allowed.

What's the plan for the 302? Stroke it out to a 331 or 347? C4's can be built pretty bullet proof nowadays. With a high enough stall, wheelie bars may be needed!

 

[donsrods]

Not trying to promote a member on here, but Ron Pope (RPM) will make you up anything you want and his prices are really competitive. He did the front and rear suspension, including axle, hairpins, spring, etc, for my altered, and it came out great. Plus, he will make it any design you ask for.

Don

 

[Bamamav]

You're welcome! It allows the suspension to work without binding. Old school tech used before ladder bars became popular, or where they weren't allowed.

What's the plan for the 302? Stroke it out to a 331 or 347? C4's can be built pretty bullet proof nowadays. With a high enough stall, wheelie bars may be needed!

I meant to say before 4 link bars became popular, not ladder bars.

 

[05snopro440]

I plan to use long (48-54") ladder bars with the buggy spring on my A. It's a setup that I know works and gives awesome traction.

I'm curious how parallel leafs with ladder bars would ride on the street. Bama, with the tubular section you mentioned, does that still help with weight transfer on the strip? Seems like your diff would be free to twist and change the pinion angle, and isn't that what you're trying to stop? I would think a sliding mount at the front of the ladder bar would be more effective, but I could be wrong. I'm just trying to learn.

 

[Bamamav]

The only time the pinion angle would change is when the axle moves up and down. The ladder bar keeps it from rotating the axle. The pinion angle will still be in line with the ladder bar no matter if the spring squats or rises. The springs only hold up the car, the ladder bar now controls the location of the rear.

 

[oldblueoval]

Thanks Don. Your build threads are kicka--!! Love reading them.[

 

[05snopro440]

The only time the pinion angle would change is when the axle moves up and down. The ladder bar keeps it from rotating the axle. The pinion angle will still be in line with the ladder bar no matter if the spring squats or rises. The springs only hold up the car, the ladder bar now controls the location of the rear.

I understand that, but I don't understand how the ladder bar keeps the axle from rotating if you've got a loose tube joint around the axle?

 

[Bamamav]

The ladder bar is attached to brackets welded solid to the axle, the spring is the only place that is mounted "loose" around the axle.

Another way to visualize it is to think of the ladder bars as being the same things as the long "truck arms" used on 67-72 Chevy pickups with coil springs. The axle can move up and down, but can't rotate because the arms won't let it. The difference is in the springs--the coils don't bind where a leaf spring solidly mounted will, thus with the tubular mounting around the axle the axle can move up and down, but the ladder bars keep it from rotating or the spring from "wrapping up" if the spring was solidly mounted.

Clear as mud now?

 

[05snopro440]

The ladder bar is attached to brackets welded solid to the axle, the spring is the only place that is mounted "loose" around the axle.

Another way to visualize it is to think of the ladder bars as being the same things as the long "truck arms" used on 67-72 Chevy pickups with coil springs. The axle can move up and down, but can't rotate because the arms won't let it. The difference is in the springs--the coils don't bind where a leaf spring solidly mounted will, thus with the tubular mounting around the axle the axle can move up and down, but the ladder bars keep it from rotating or the spring from "wrapping up" if the spring was solidly mounted.

Clear as mud now?

Ok, that makes more sense. I was thinking you meant the loose mount around the axle from the ladder bars, not the springs. Maybe I should read slower next time.

The loose mount on the springs with ladder bars would work well.

 

[Dr Crankenstein]

A leaf spring changes in length. A ladder bar does not. The combination will bind unless the axle is free to "float" on the spring...

So, if you allow the axle to both slide on the spring (bob w) and rotate freely (Bama) you eliminate bind, at least in "square" vertical motion.

.

 

[Bamamav]

Thanks for the confirmation Dr Crank. You have probably seen both methods used and in action, so you knew what we were saying.

 

[26Troadster]

bobw and bama have got you going in the right direction. i always used competition engineering axle floaters.