Steering U-joint Question

I feel like I've read on either the Ididit or Flaming River sites that an a carrier for the steering shaft is often needed when more than 2 u-joints are used in a set-up. Does a double joint count as 2? I am hoping I can get away with 2 single joints (one at the base of the column and one at the steering box that replaces the rag joint), but the upper joint will be right about at the max limit for angle. It seems if I put a double joint there, the steering starts to get wonky - thus maybe a shaft carrier is needed?

 

Decided to try notching the motor mount and use a single joint between column and intermediate shaft, plus the one at the saggy box....I think this might work...

 

How much clearance does one need?

 

Maybe it requires the angle of all the joints to be in the same plane or equally out of plane in opposite aspects, but when I replace the single joint with a double joint, the 2nd joint and lower shaft starts moving in a circle. Not surprising based on the borgeson and Ididit discussion, but just confirmation that its is needed for 3 joints.

The lower steering shaft is a 3/4"-1" double D telescoping shaft. the 3/4" section goes to the ujoint at the saggy box which required a 30 spine to 3/4" DD joint. I think it goes 17-24" and I am somewhere in the middle of that range. In addition to safey, I just find it much easier to get stuff all installed and removed (which I have now down way too many times) with a slip joint.

Its close to the limit for sure....I have a double joint that I can replace it with, but then the carrier bearing is needed of course. That can be done, but wondering more about the clearance around the motor mount. The double joint is longer will drop the shaft just a bit more, giving just a smidge more clearance, but its not really significant. If the motor mount clearance needs more, then its more what you describe, with a short section of shaft and another single joint (plus the support bearing).

In ether case, I guess the support bearing would need to be mounted to the inside of the frame rail just behind the motor mount. How adjustable are those support bearings in terms of getting them positioned right - basically, are they length adjustable, or do I have to control that with the mount. Also, the shaft is not parallel to the frame rail, so how much angle can they work with? I know there is a sort of spherical/heim joint style bushing/bearing in it that I assume can accept a reasonable amount of off-angle?

 

Maybe the picture is a bit deceptive as its taken looking down and not showing the true angle from the side....I am more worried about the maximum joint angle and shaft interference with the motor mount than premature wear, assuming it just get sloppy and sticky etc as opposed to catastrophic failure at speed....Borgeson says maximum angle of 35 degrees (on a single joint) and when i was testing some different arrangements, anything at 35 degrees or so, and you can feel it bind and stick and jam up. The angle I have is just over 30 degrees on flat ground - it works fine as is, but its more a question of how much flex will occur. I am going to re-install the set-up as is and get a better angle measurement, and the maybe try jacking up different corners to see how it affects things.

I don't know whether it 'matters' or not, but you can definitely see it when you watch it....it was a bit eye-catching, but I know I've driven some similar set-ups and never 'felt' it when driving.....

 

there is very little angle at the bottom joint - it was a rag joint that I replaced with a u-joint as CW seemed to suggest that was much better. The box was mounted with the nose down more than any other I've have seen, i think specifically to accommodate the prior rag joint and keep the lower shaft straight into into the box - and it worked fine for the front cradle mount. But the side engine mounts are further back, and right in the pathway...by notching the mount, I am keeping the lower joint angle very small, and reducing the upper joint as much as possible. Its all a combination of trade-offs I guess....but I don't always know what I am trading off. I don't like gambling, and even less so when its blind.

nothing makes me comfortable with my work - not enough experience to know, and too much of what I do only kind of works out right....Some future owner will definitely be making 'can you believe what the PO did here' comments!