47-55.1 DD Steering Rod wet noodle

[NeoJuice]

Ok I made a stupid mistake. A long time ago when assembling the truck I mounted my steering column in the lowest position in the stock column hole. Later on I found out my under floor brake pedal comes very close to the bottom of the steering column and your foot hits up against the column making it very unsafe.

After thinking about a solution to this problem I removed the floor column mount, cut out the metal I welded in to fill the top of the hole. Welded the mount bolt holes shut and decided to start again.

I adjusted the dash column mount and set the new floor mount location at the top of the stock hole. After making this move I now have plenty of room for the brake pedal and plenty of room for your feet from hitting the column.

With the increased angle now of the column I ordered up a double u-joint from speedway motors because the normal joint angle was not going to cut it.

After doing some test fitting and trimming of the DD shaft I got everything pretty much where I want it. But here lies the problem........Before when I had the column in the lowest position my Heim joint kept everything stable and firm with no flopping and was as smooth as butter.

For testing purposes I temporarily mounted the Heim bracket about 1.5-2" higher then it was before to check for stability. Well as you can see it's flopping around like a wet noodle which I'm not happy about so I'm looking for a solution to my problem because I just keep staring at it over and over trying to come up with a solution.

Option 1 - Move the heim joint up closer to the double U joint and make a bigger bracket because it's up so high or maybe off the firewall

Option 2 - Move the heim joint right next to the middle u joint to stop the flopping around. The heim would still be located on the upper D shaft just sitting right next to the u joint.

Option 3 - Somehow add another heim joint to the lower DD shaft to stop the wet noodle from flipping around. This would almost appear to be impossible between the frame, header & inner fender clearances. This would also be used in conjunction with the upper heim joint/mount to make things stable.

If this was the case I would assume that for every section of DD shaft a person has there should be a Heim. I was looking at this thread https://67-72chevytrucks.com/vboard/...d.php?t=810497 and he only has one as I did before.

But I'm wondering the issue I'm experiencing now is because of the double u-joint instead of the single one as before.

I've included a couple pictures of the old setup and videos to show the new setup. You can see how tight of a space I'm dealing with now that the front is back on the truck.

Videos: https://photos.app.goo.gl/c2VDdnstPxnXXcVaA

Thank you.

[1project2many]

That's actually a three-joint shaft, yes? The angles between the three U-joints are very different. This causes the lower shaft to turn at inconsistent speeds. It can also cause the upper joint to bind or to move the shaft around.

Also, are the U-joint yokes butted against the end of the shaft? Are the bolts tight? Try loosening... you might need a slip joint.

[joedoh]

try option 4, move the heim to the lower shaft. the column is rigid, moving the heim to the lower shaft will make it rigid, so the double joint on the upper shaft will not be able to swing around.

[NeoJuice]

Originally Posted by 1project2many

That's actually a three-joint shaft, yes? The angles between the three U-joints are very different. This causes the lower shaft to turn at inconsistent speeds. It can also cause the upper joint to bind or to move the shaft around.

Also, are the U-joint yokes butted against the end of the shaft? Are the bolts tight? Try loosening... you might need a slip joint.

Yes three joints. I have a spline u joint on the steering rack with DD to the middle then DD up to the top double u joint.

The set screws on the bottom spline joint are drilled and locktite. On the middle u joint the bottom set screws are drilled and locktite. I had to remove the set screws from the upper middle so I could remove the shaft and shorten it.

I haven't drilled a divot on the upper DD shaft yet for the set screws because I wanted to test everything before making it permanent. The set screws are tightened down with an Alan key for testing.

[NeoJuice]

Originally Posted by joedoh

try option 4, move the heim to the lower shaft. the column is rigid, moving the heim to the lower shaft will make it rigid, so the double joint on the upper shaft will not be able to swing around.

That's understandable to do that but the problem is there is no room to move the Heim to the bottom DD shaft as I mentioned lack of space between the frame and header. Can you buy a slip joint DD shaft?

Any thoughts on option 2?

[joedoh]

Originally Posted by NeoJuice

That's understandable to do that but the problem is there is no room to move the Heim to the bottom DD shaft as I mentioned lack of space between the frame and header. Can you buy a slip joint DD shaft?

Any thoughts on option 2?

option 2 will not change the problem, you will still have an unrigid upper shaft and an unrigid lower shaft, both pivoting on the heim. thats where your wiggle is coming from.

you can buy a slip DD but its also not going to solve your problem.


you will have more room on the lower shaft heim because your upper shaft can take more angle than it used to, so just scoot it out and make it fit.

[NeoJuice]

Originally Posted by joedoh

option 2 will not change the problem, you will still have an unrigid upper shaft and an unrigid lower shaft, both pivoting on the heim. thats where your wiggle is coming from.

you can buy a slip DD but its also not going to solve your problem.


you will have more room on the lower shaft heim because your upper shaft can take more angle than it used to, so just scoot it out and make it fit.

Thanks joedoh, I appreciate your expertise. I love your truck and fab skills, I also follow your build thread.

I'll have to figure something out then to get that Heim on that lower DD shaft and from what I understand I should only need the one lower heim correct?

[joedoh]

thanks for the kind words!

I hope I am not being too matter-of-fact for you, i speak clearly to not be misunderstood and it can get misinterpreted. I have to do this exact job (mii, high angle joint, heim, V8, around exhaust) for a friend so its helpful to see what guys have done.

[mongocanfly]

If you dont have room down low, then you could add a heim to the center shaft, having 2 heims on it would make it a solid mount, vs the teeter totter effect your getting....and I'd make those heim brackets out of something a little thicker than what you have..that looks pretty thin..

[NeoJuice]

Originally Posted by joedoh

thanks for the kind words!

I hope I am not being too matter-of-fact for you, i speak clearly to not be misunderstood and it can get misinterpreted. I have to do this exact job (mii, high angle joint, heim) v8 so its helpful to see what guys have done.

Not all all. Just looking for clean answers all the way. I also come into a different position because of my old school sanderson headers as someone would maybe have the same problem with GM RAM horn style headers.

[mongocanfly]

Ad I'd loose that cardan joint at the top..not sure why youd need that...that's causing alot of your problems

[NeoJuice]

Originally Posted by mongocanfly

If you dont have room down low, then you could add a heim to the center shaft, having 2 heims on it would make it a solid mount, vs the teeter totter effect your getting....and I'd make those heim brackets out of something a little thicker than what you have..that looks pretty thin..

Thank you Mongocanfly for the input. Adding an additional Heim up higher was a thought I had as well. But being up that high again comes with the tricky task of making a bracket and where and what to mount it to. Thank you for the picture reference as well.

I made the bracket out of 1/8" flat steel, do you think that is not thick enough?

[NeoJuice]

Originally Posted by mongocanfly

Ad I'd loose that cardan joint at the top..not sure why youd need that...that's causing alot of your problems

Can you explain cardan joint? Do you mean the double u joint at the top?

Regards,

[mongocanfly]

I wouldnt make a bracket for steering with anything under 1/4"...thicker than that's even better..3/8 or 1/2 is my go to for that...
I can bend 1/8" with my hands so imagine how much force your exerting on it with the steering...
And yes ..a carden is a double ujoint...

[joedoh]

Originally Posted by mongocanfly

Ad I'd loose that cardan joint at the top..not sure why youd need that...that's causing alot of your problems

std u joints are only good for about 30-34 degrees, before they biind or start knocking against itself. any more than that and you need a double, good to ~70 degrees.

[mongocanfly]

I agree Russ but from what I can see he doesnt have much angle where its at... until he turns the steering wheel

[joedoh]

I cant say you arent right, but he does say in his post the original didnt cut it. its hard to see angles in pictures, maybe its toward the camera?

[mongocanfly]

(but he does say in his post the original didnt cut it. )....

I missed that...

Would be real curious to know what each joint angle is though..

[dsraven]

http://www.borgeson.com/joints.html

I agree with the strong bracket. also try to keep the angles of the shafts sort of similar because otherwise the joints fight each other and cause the shaft to speed up and slow down as you turn a constant speed with the steering wheel. this site has a good youtube to explain how it works.

https://shiftsst.com/blog/post/driveline-angles.html

any chance of fitting different exhaust or raising/lowering the engine for better clearance?

[NeoJuice]

Originally Posted by mongocanfly

I agree Russ but from what I can see he doesnt have much angle where its at... until he turns the steering wheel

I think it appears that way in the video because the bottom DD shaft is flopping around side to side and it's straightening out up near the column.

[jweb]

I have a similar steering set up and there was no need for a double joint at the column.

As mentioned above the standard joints are good to about 30 degrees, I don't think you need the double joint with the 2 piece shaft you have.

You could also do a rear dump header or manifold on the driver's side. I had '78 C-10 manifolds when I had a 350 in my truck

[NeoJuice]

With everything in alignment on the lower DD shaft spaced nicely between the frame and header you can see the angle of the upper double U joint. Attached are some pictures I took last night.

I'm still figuring out a plan and location I can put another heim on the lower DD shaft. Do to space restrictions it might have to go down by the steering rack but I'll have to take a closer look under the truck.

[joedoh]

ahhhh you are using it as an offset. makes sense now.

but you could use a single joint the same way, flip your heim so it is on the other side (pointing to the inner fender) and keep the same "jog" with the upper shaft.

[mongocanfly]

Yep....what Russ says...
Run your shaft out at more of a angle..

And it would also be easier if you had a slip joint in there somewhere...
I know your limited for room..so you may not have room for it

I dont think putting a heim down low is gonna help much with that carden...
If you have to keep the carden then you need double support on the shaft below the carden..

[jwhotrod]

the problem lies with the double joint at the top. you can have 2 joints in a shaft without support, when you add the third joint you need a support bearing. here that double joint without support close to it will be very erratic. so leave the bearing you have where it is and add another support bearing close to the double joint where the shaft turns smooth. the two bearings on that shaft will stabilize both that shaft and the lower one as well.