Steering shaft upgrade

Ok, so here's part II of what I did to upgrade my steering shaft. The stock coupler leaves a lot to be desired. More than likely yours is worn out. They sell rebuild kits, but after all of that the spring clip is hard to get on, and when it comes off it makes a mess. And then it wears out again.

So, lots of folks are going to steering u joints. Less play, and they can provide more header clearance. But then the question of binding comes up, because the stock coupler also slides in and out. I don't actually think this is a huge deal, but I figured I'd humour the doomsdayers and see if there was something I could do about it.

What I came up with was a telescopic DD shaft from Borgeson that I bought here. This is a short one, 13" fully extended, 9.5" fully collapsed. And, it goes from 1"DD to 3/4" DD.



The 3/4DD side allows the use of most steering couplers, including this beauty from Borgeson, #034934. This ones a 3/4DD to 3/4" 36 spline vibration damping u joint, and it fit my Flaming River steering box great. **Disclaimer** not all mopar steering boxes use this size!!!

I got mine from summit, here. $110. Not cheap, but since nothing else will dampen the vibrations anymore, I went with this one. One disadvantage to this one is its almost exactly the same diameter as the original, so, not much header clearance savings.

Next is the hard part. I cut the power steering shaft that I had and ground and filed a notch in it to accept the 1" DD telescopic shaft end. I did this so that it wasn't butt welded together, and because it made it easier to keep the shaft aligned properly. After all, I fit this with a ER16 bearing at the lower column, so no play to make mistakes. You can see that the steering shaft is 1" at this point, so you're left with a couple of little "tabs" that slide over the flat sections of the 1" DD shaft. After all, the outer diameter of that is 1" on the rounds.



I then clamped the steering shaft and telescopic shaft together in a piece of channel I had to keep everything straight, and welded it together.



Unfortunately, this is where I messed up my "how to". I stopped taking pictures and I forgot to write down the length of the stupid steering shaft where I cut it to set it up for my Flaming River steering box. I may have to pull the steering shaft and get those measurements for you guys. Anyway, I set it up so that the telescopic section of the steering shaft was collapsed about 1", so, it will still extend up to 1", and collapse up to 2.5". The additional extension I left mostly in case I change to a regular steering u-joint at some point, or if they change the length of the vibration damping unit. You'd want to leave a little extension for body flex, but a 1/4" would be more than enough for that. After all, the point was to prevent the u-joint from binding if there's chassis flex.

Keep in mind that cutting and splicing the telescopic section DOES keep the original collapsing shaft from collapsing as far as it normally would in an accident. BUT, I know the original part of the shaft will still collapse close to 6", and the telescoping section will collapse another 2.5", so that should be plenty. If its not, you're in trouble anyway.

Next I fit the lower column bearing (see this thread here), drilled the 3/4DD end of the shaft for the set screws, and reassembled the whole mess.





And then put it in the car! :cheers:

Yes, the coupler looks HUGE. Most of it is the angle of the photo. I measured it, I swear its a little less than the diameter of the original coupler. Also, you could skip the vibration damping piece and just put on a regular U joint if clearance is what you're looking for here.

Man that coupler is huge. Do you feel a difference in the steering?

74DartSwinger360 said:

Man that coupler is huge. Do you feel a difference in the steering?

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Yeah, that is a draw back of the vibration damping unit. Hopefully it clears my Doug's headers. It should, it's just a touch smaller than the stock coupler on the wide part of it. Of course if it doesn't I'll just switch it out with a plain steering u joint, there should be more than enough extension in the telescoping section for that.

As far as a difference, its not on the road yet. No engine in that picture...

72bluNblu said:

Yeah, that is a draw back of the vibration damping unit. Hopefully it clears my Doug's headers. It should, it's just a touch smaller than the stock coupler on the wide part of it. Of course if it doesn't I'll just switch it out with a plain steering u joint, there should be more than enough extension in the telescoping section for that.

As far as a difference, its not on the road yet. No engine in that picture...

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Almost seems bigger than stock in pics. And didnt know if this was recent or old pics new thread kinda thing...Although looks like the paint is the color of your 71

74DartSwinger360 said:

Almost seems bigger than stock in pics. And didnt know if this was recent or old pics new thread kinda thing...Although looks like the paint is the color of your 71

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Yeah that's the angle of that picture, it does make it look bigger. Trust me, I measured it before I did all that work, the diameter is just a bit smaller.

I did the work last week, its in my '74 Duster. Little lighter than the Butterscotch '71, I think that one's called "golden fawn". :toothy10:

72bluNblu said:

Yeah that's the angle of that picture, it does make it look bigger. Trust me, I measured it before I did all that work, the diameter is just a bit smaller.

I did the work last week, its in my '74 Duster. Little lighter than the Butterscotch '71, I think that one's called "golden fawn". :toothy10:

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Oh thought duster was running and driving. oh well dont matter what car it is still cool

74DartSwinger360 said:

Oh thought duster was running and driving. oh well dont matter what car it is still cool

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Haha. It was. Long story. In less than a year its been a /6 car, a 318 car, and very soon to be a 340/4speed car. Didn't update my sig when I pulled the 318 a couple months back.

72bluNblu said:

Haha. It was. Long story. In less than a year its been a /6 car, a 318 car, and very soon to be a 340/4speed car. Didn't update my sig when I pulled the 318 a couple months back.

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Oh Sweet gonna be a fun car. Gonna leave it looking as is for a sleeper look?

74DartSwinger360 said:

Oh Sweet gonna be a fun car. Gonna leave it looking as is for a sleeper look?

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For awhile. Eventually it's going to be a Demon. I've got a '71 dart front clip already, but I want to get it sorted mechanically first. At the rate I work that probably means it'll be a few years. It's going to get 18's with big *** tires before then, so not entirely sleeper.

Cool deal, my brother used a jeep u joint steering shaft from a grand cherokee on his 87 monte carlo ss he is restoring. Got rid of the infamous gm " rag joint" so yes i can def see an advantage to doing this. Stiffens up.the steering.

Great tech. Thanks for sharing. We need more threads like this on fabo.

Great job Brian. I'm getting ready to install a new set of Doug's headers on my Cuda and have a Flaming River U-joint I plan on swapping on at the same time. I bought it used over the net and wasn't told it was for a double D column but I got it cheap enough so I was thinking of a plan on how to adapt it to the stock steering column and have it slide in and out since I've read so many times that they have to because of the power steering box. The replacement bearing you came up with is a great addition too. Mine's not bad but I think for that small price I'll go ahead and swap it out.

Thanks!

I'm still honestly not convinced that the telescoping section is 100% necessary, there's more than a few folks that run steering u-joints without it. But, after thinking about it for awhile and finding the parts that I used to do it I figured that I could manage it easy enough, so why not. If it saves some wear and tear on the steering box, then awesome. And if it just extends the life of the u-joint, that's good too. Plus, the telescoping section gives me a little adaptability if things change down the road, so hopefully I won't ever have to do anything to modify the steering shaft again even if I change steering joints, steering boxes etc.

I do like this solution far better than the steering u-joints that have a straight round section. Those are intended to be welded on, and putting a pin through them doesn't make me feel good. Then you can get wear at the pin, not to mention there's nothing other than the pin keeping the shaft from spinning in the u joint. This way all of the joints are held together by the DD sections, even the welded part. The only part that can get you is the telescoping section, because it does collapse enough to slide the u-joint off. That's why I countersunk the set screws fairly deep. There shouldn't be any real strong forces acting in that direction, but for peace of mind they're countersunk and loctited.

NOT meaning to highjack thread ... BUT is there something you can buy ... to eliminate the factory joint for a manual steering system ?
By the way .. nice fab!

rrvolare said:

NOT meaning to highjack thread ... BUT is there something you can buy ... to eliminate the factory joint for a manual steering system ?
By the way .. nice fab!

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Sort of. And its not a hijack, that's actually why I did what I did with this fab.

You can buy a steering u-joint that will go from the 3/4" 36 spline or 5/8" 36 spline steering box to a 3/4" round, which is what the steering shaft is at that point. You just trim the end of the steering shaft to the right length.

The problem is that you either need to weld that joint onto the end of the steering shaft, or drill it and put a pin in. I don't like the pin, because if its not a perfectly round hole and the proper tolerance for the pin you'll end up with slop in the steering system. So, you basically need a machine shop to do it right, its not a typical do it at home operation. Or you need to weld it, which means you're not changing that u-joint any time soon. The steering u-joints for round ends are intended for racing, and intended to be welded.

Or you can buy a really expensive adaptor from flaming river, but even that just goes up higher to the 1" diameter section of steering shaft, and then has the same pin or weld issue.

The other issue is that the stock coupler slides up and down, which the u-joints won't do. So, if you incorporate a u-joint without a telescopic section you could, IN THEORY, introduce a binding problem when the chassis flexes, or wear out the steering box or u joint prematurely because of those stresses. Now, on an A body, with the steering angles that are set up from the factory, I'm not sure that part of it would be a big deal. Plenty of people run just a plain steering U joint with no sliding/telescoping section. For me, I just really dislike the pin that holds the u-joint to the shaft when its done like that. Its not a hand drill, or even a drill press type operation, it should be machined to be an interference fit with the pin to do it properly. If there's any slop between the pin and the hole, ie, anything other than a press fit, the pin and hole will wear and introduce play. And eventually ruin the steering shaft too.

The other way to swap it over to a steering u-joint would be to have the 3/4" round section at the end of the steering shaft machined into a DD shaft. That just requires milling some flats into the solid round tube. Then you'd just use a 34" 36 spline to 3/4" DD steering U joint, and that would eliminate the pin or weld issue. But it would still require a little machine work. You can probably grind the flats into the shaft also, but then you're traveling back down the path of introducing slop in the system if you don't grind everything true and flat.

This is all stuff I thought about when I did my modification. You could also weld in a section of 3/4" DD shaft to the end of the steering shaft, but then you're cutting and welding and still haven't addressed the up/down movement issue. Which is why I decided to weld in a section of telescoping DD shaft. Solves all the issues, and doesn't require a machine shop as long as you're careful to make sure the ends of the shaft stay aligned.

Thanks 72. I have used that same vibration coupling from Borgeson for several years now on my 66 Cuda and 67 Dart. I didn't give much thought to the in and out movement till I saw your thread. Have to rethink my columns now.

Subscribed for my near future reference. Great work!