Rear spring shackle question!!!

[Lucas1923t]

I have a 1923 t bucket that is using what I beleiive is the original spring. The bushings were worn out on the shackles so I decided to replace them. I ordered a set of 2" shackles from speedway and they really don't fit correctly. They mount the spring to close to the bracket. I posted a couple of pics so you can kind of see what I'm talking about. When comparing the two shackles the old one is 2.5" from center of bolts. The new is 2". Anyone know if they make bigger shackles?

I would also like to drop the rear of the car a litttle so its not so high. Whats the best way of doing that with the set up I currently have? I noticed most of these type of cars are built with a Z in the back so the frame kind of falls aroung the axle which lowers everything nicely. I'd like to lower this as far as I can without major fabrication.

Thanks for your help

 

[LumenAl]

I've never seen a setup like that... but I believe the shackles should be at about a 45 degree angle under load and yours are almost straight up and down... If it were me, I'd be looking to redesign a new bracket that would put the shackles in the correct position... I have a couple of ideas but lets see what some of the more experienced builders say...

 

[Ted Brown]

It almost looks like the whole set up is mounted on the top of the bracket, and it may be supposed to be mounted on the bottom, up side down, and yes the spring is not spread near enough, as how it sits with no weight on it, the shackles should be straight out, then when all the weight is on the spring, it (the shackle) should rest at a 45 degree angle, like Al said. You can also use any width shackle, I always us shackles 1/4 inch wider than the spring, to help eliminate bind as the car moves up and down, the radius rods move the rear end back and forth a bit, depending on their length. I have a set of shackles in my hand and they are 2 1/4" wide and 1 1/2" from shaft to shaft, so your's are bigger already. Hope you made some sense of this, if not message or e-mail me for better words and pics..

 

[Tbucit]

A few things, I go along with AL I have never seen thing like this, but that doesn't make it bad. First to lower the frame you might cut the cross member off and space it up with some tubing on top of the frame, if you have enough room not to contact the spring and frame. I have a little concern that the radius rods are welded to the housing instead of rod ends or clevises, may work fine but if I did it it would bind up for sure
Ted is right on (which no one here should have any doubt about) about the shackles, my current project is the first one I have used this set up on but there are plenty of pictures on the web that show how this works.

Keep us posted on the progress
Randall

 

[oldtman]

rear suspension, definately rework the rear hairpins to have adjustment and allow movement or the welds or tubing will eventually break.the next question is how much horsepower will you have My 3 rd chassis had a small tube about like yours with 375 HP and 4.56 gears the hairpins bent-broke.check out your speedway or RPM for ideas ,brackets .. larger hairpin tubing also new spring hanger brackets mounted lower on the axle. all the cutting and welding can warp the housing. It should be checked. I reworked one crosmember by making 4 cuts on the legs of the u channel ,,,cut out a wedge each side to pinch and added one to fill ,,It lowered it about 2 inches ..with the correct shackel angle most guys don't run the panhard bar. If the spring is streached enough the rear usually won't rock sideways.

 

[Youngster]

the spring mount you have are of the same type that was used for the rear sping on the mid '50's fords. the way they are mounted is part of the reason the rear of your car sits so high. look at a set of rear housing brackets from RPM or Speedway. be sure to mount the new spring mounts 46" apart so as to give the shackle room to work without hiting the mount. unloaded, the spring shackles should be nearly flat. these will lower the spring 6" or better. with the front end you have, you might not want to go lower than that or your frame will be higher in the front than it is in the rear.do this modification before you do any cutting on the frame. if you want to lower the front more you will need to fashion a new frame spring perch.

as oldtman said you will want to redesign your rear hair pins. lots of forces working against your set up. here again RPM or speedway has what you need. you will also be able to dial in your alignments and pinion angles that way. weld the hair pin brackets on after you set the spring up. since your spring is mounted to the front of the axle housing, the spring will need to pass between the tubes on your hair pins.

if your frame rails are straight ( no kick in them) your car is going to sit high. to lower it you will have to put a kick in the back and a raised spring perch in the front..

Ron

 

[Youngster]

these are not minor mods to what you have now but they would result in a safer and more enjoyable car.

Ron

 

[Lucas1923t]

I see RPM has a nice set of hair pins that includes everyting I need. Those should work fine. I think that would be a smart move on my part.

I'm trying to figure out what the rear housing brackets look like. Do you have a pic?

Thanks again for all your help!!

 

[Ted Brown]

Whatever you buy, be sure it has bushings like they use in 4 bar setups, this will keep everything alive, and give a little when cornering and such on the street, Race cars don't worry about this, as they just go straight (hopefully hehe ) and on flat ground.. Solid conectors make for a bind and things will break in time..

 

[Lucas1923t]

Ted,
When you say bushings, r u talking about rubber bushings. I'm trying to figure out where they would go. On the Hair pin you have three mounting points that normally would use a clevis and 5/8" bolt? Where would the bushing mount?

Thanks

 

[Youngster]

there are a number of housing brackets for the hairpins. that why i suggested you done the spring mount first. after they are on you will be able to see which hairpin bracket will work the best.

one other thing to consider here is the length of your hairpins. if you have the engine and trans in the frame. try to attach the front of the hairpin directly across from the front u-joint on the frame rail. this will keep the swing aches the same on both the hairpins and the drive shaft. this is where ordering your hairpins from RPM will be a plus. Ron can make them what ever length you need.


Ron

 

[Ted Brown]

Ted,
When you say bushings, r u talking about rubber bushings. I'm trying to figure out where they would go. On the Hair pin you have three mounting points that normally would use a clevis and 5/8" bolt? Where would the bushing mount?

Thanks

look at my Radius rods, they have the 4 bar bushings at all three points, (they can be made just like a heim-joint, mine are welded on) {I make my own adjustable bolts, nothing to work loose} if the car ever leans, and what street car does not lean? it has to have give, or something is bending or twisting, can't lean without doing this... that is also the reason to NEVER use Heim joints for suspension links, only to be used on tierods or panard bars, with absolotely no side stress... and still must be safety washered...

 

[Ted Brown]

Radius rod length, mounting at the front driveshaft U-Joint, is way too short as far as I believe and do... I have mine both, Ft and rear mounted to one common bracket welded to the frame.. I have over 200.000 miles on my T all with this setup, great traction, no wheel stands, years ago I did break a lower tube, not a large enough dia. Tube, and they need at least .188 (3/16)wall and 1 & 1/8 Min. OD Dia. tube, I now use square tubing for all bottom rear lift bar tubes.. as square is a lot stronger than round. at least twice... NOTE; that is if you run any high horse power engine.

 

[YblockT]

look at my Radius rods, they have the 4 bar bushings at all three points, (they can be made just like a heim-joint, mine are welded on) {I make my own adjustable bolts, nothing to work loose} if the car ever leans, and what street car does not lean? it has to have give, or something is bending or twisting, can't lean without doing this... that is also the reason to NEVER use Heim joints for suspension links, only to be used on tierods or panard bars, with absolotely no side stress... and still must be safety washered...

Hi Ted, I'll take the liberty of posting a couple of your pics that illustrate the bushing I believe you're talking about. You can elaborate further. (P.S. Been busy this week, so excuse my forum absence)

 

[Youngster]

just 2 schools of thought i guess. as with alot of chassis fundamentals, some apply and some don't. and as ted pointed out, there are other factors that come into play.

Ron

 

[LumenAl]

So if I'm understanding this correctly, it's like putting typical 4-link ends on a radius rod?

 

[Lucas1923t]

Thanks for all the help guys.

I talked to RPM and he's setting me up with everything I need. I'm hoping on getting everything in the car in the next couple of weeks. I will let you know how I make out. Thanks again!!