How safe are split bones on rear?

Cool, I am also running an early Cad 331. I was gonna use the Hydro but went away from it because of the rebuild costs of the Hydro and the length of it. I am now using the T-5 and a 36 rear with 36 rear radius rods. Also using the banjo because , planning to use a QC when I find the money in my pockets.

I am asking because you can do away with all the concerns by using the 4WD T-5 and the TT kit from Crazydaddyo. Here is the Kit. If you use this kit you can use the Ford TT and do away with all these "what ifs".


I look at this way. If I buy this $500.00 kit, I can just use stock stuff and just shorten the TT, drive shaft, and radius rods and done. Ending up with a rear suspension as Henry Ford intended. I also figure that the drivetrain modifications, building new 3 or 4 links suspension, making the appropriate drive shaft mods, and rear axle open conversion costs can exceed the $500 for the kit.

Its your car and your money do as you want, Just my $.02

 

By a wishbone spliting kit from Chassis Enginering ,they use tie rod ends that have plenty of articulation,are greasable and are designed for the stress of steering. Look how well they hold up. Never use heim joints on a street driven car.I have split bones on my 32 on the rear for 3 years on Pennsylviana roads with no problems

 

I agree that that is a good way to go. No interference movements and no science fair suspensions.

 

not to keep re-hashing this issue, but i was just looking through the '60s style t bucket thread, and i saw a BUNCH of cars with split bones mounted to the frame.

I've been on the t bucket boards for many years and i can remember ever hearing about anyone breaking a split bone on a bucket....

any reason for that?

does it have anything to do with the angle that the bones mont (sorta like a triangle) or is that i've just never see a story about it or has everyone with a bucket just been lucky or what???

Reason i ask, is that i'm getting ready to start on my bucket and the ONLY thing i havent settled on is the rear radius rods...

hair pins???

 

Everyone says "I have seen it done that way on T buckets with no problems for years", Well my argument for that is a T bucket weighs almost 1000 lbs less and there fore the see much less stress on any and all suspension components. Additionally ever see a T bucket hook up and get traction? No, again little to no stress on suspension components.

Sorry, I am not a T bucket fan. I would rather ride down the road in a Shrinners car than ride in a T, I would look stupid in either but at least the Shrinner car doesn't move fast enough to kill me!

 

I was thinking the same thing. Do they all have a top link or torque arm that you cant see? I am asking because I am currently thinking of a way to build a torque arm on my T. Anouther question, sorry not trying to hijack the thread, is a panhard bar nessary for split bones with the ends close together such as the pic I posted earlier? One guy I was talking to about it said with the mounting close to the middle of the car there is alot of force wanting the rear end to move side to side.hair pins.

 

I've been wondering the same thing for years. The vast majority of the split rear suspensions I have seen would fall into the category of 'gee, that doesn't look quite right'. Yet the builders swear by what they have built.

Some of this might be pride of authorship. Maybe some of these suspensions do indeed work. I suspect, however, that the following factors are more likely to be true:

1) Most of these cars are not driven very much
2) When they are driven, they are driven on roads that are not too bad
3) If the car has light weight and a stiff rear suspension (high spring rate) then the effect is mitigated
4) Most of these cars 'go away' after a brief life (not too many survivors - I have one, it was built in 1953 and guess what, it has unsplit bones with a torque tube)
5) After accounting for all of the above factors, sometimes these cars do encounter suspension problems. The worn parts/failure just gets chalked up to 'getting on it', which in everyone's mind is a lot more socially acceptable than 'I designed and built it bad'. Something wears out: maybe the arms or the end joints have been flexing for years, and finally metal fatigue sets in.

No one has ever, to my knowledge, done an accurate analysis of the problem or what really happens to these cars. It would be illuminating if some of these cars were put on a chassis plate, and the relative motions of the rear suspension measured accurately and charted, so that the weak links in the chain could be identified and 'best practices' established.

But that probably ain't gonna happen. In the end, everyone will continue to build what they think works. IMHO, whatever you build or how, you should be cognizant of the interference motion and aware of what component(s) are flexing to accomodate it. Forewarned is forearmed.

 

I think they'll be fine.. Here are mine working.




Jack Strunk at Dropped Axle Productions in Cincinnati, did the set up.

This car has 65,000 miles on it to date.. on Shit ass Ohio roads.

Car weighs 2400 lbs.

I agree with all that has been said. It's just a matter of doing it right the first time. Think things out, and understand the "workings" of suspension. It's mostly common sense stuff.

J Shaw

 

I wasn't sure either if you were talking about useing the buggy and 1/4's with the split bones.Sorry it's taken a while to get back to this.My wife and I drive an 18 wheeler an I try to get on here for at least a few minutes at each driver change.(around 0900 & 2100 hrs)Just wasn't any time last night.Gotta hustle sometimes.Thinking seriously about the buggy and 1/4 eliptic set up.I'm sticking with the 331 caddy for sure but now thinking about a t5 myself as I really don't know the condition of the hydramatic and concidering a dana 44 out back since I'd probably be nervous about hammering any rear w/ keyed axles.I know the 44 isn't what pops into everyones head when they think traditional hot rod but they were used in early 50's f100's.Not on purpose,but I seem to have something of an f-100 thing going on with effie front brakes,steering box,column,etc.I still like the look of split bones but coming to the conclusion that its probably not worth it.

 

NP. There's another thread going that is talking about Super Pivot ends. Supposedly they provide the articulation needed. Might be something to look into.

 

The articulation resistance comes from the hard connection directly at the rear axle, combined with having the radius arms attach at the frame and NOT focused to the center of the car to simulate the original configuration.
The issue isn't the style of bushing/pivot at the front mountings...its the actual spreading apart of the radius arms that creates the binding.

 

100% agreed.

 

Yeah I realize by spreading the ends to the frame rails you're basicly creating a big anti-sway bar.One that is NOT designed to work as such.While splitting the original front pivot point and keeping them toward the center of the chassis does induce binding it seems to me its not to the same degree as moving them out to the rails.It seems to me that the farther you move the ends in the more you're putting them inline with the pivoting of the rear axle.Also,anyone know what year torquetubes fit my '40 rear in case I decide to use it?Someone posted some pretty good tech on here on making your own open drive conversion.Anyone got a bent one maybe?All I need is the last 6" or 8" off the end.