rag joint insight

[Werner R.]

Re: Twenty Years ago I had the privilege

nice explanantion, but you left out one minor detail, and i hope you comment on this.
the lower end of the steering shaft has a large flat surface which gives clearance to the clamping bolt of the upper coupler. there is NO possibility of connecting the upper coupler 180 degrees out of phase becauses then you could not insert the clamping bolt. not even the mother of bubbas could do this!
therefore, since "out of pahse" insertion of the upper is physically impossibe, it makes no sense to diddle with studs etc.
also, i looked carefully at the input steering box shaft of 3 steering boxes, and i can find no hint of anything other than complete even splines around the entire shaft. well, maybe these three are bogus or foreign [not], but if they are correct [they are], then i don't know where you saw some uneven splining of the box input shaft. of course the output shaft has 4 evenly spaced missing splines so that the pitman arm can only be in one of four different positions.
i really liked your theory about the stud making noise as it contacts the upper coupler of a failing joint. john, can you possibly imagine hearing this while traveling down the road. if your ears are that good, then you ought to get a job with NASA listening for radio signals from distant planets.
i also looked carefully at several different kits, and all four hex nuts have exactly the same internal diameter and interchangeable; bolts/studs.
finally, john, i gotta say i love you and the posts you've given in the past. i've learned alot from you. i hope you don't think that my disagreement with you is personal. far from it. i find all of this stimulating, and this give and take is part of the joy of owning a vette and being a board member.
and really finally, i take it that your silence about the u-joint function of the rag joint is capitulation on that point. hmmmm? grey cool weather today and the vette is in the paint shop for a redo of a minor repair they did 2 years ago. i miss my car.

[John H.]

Re: Twenty Years ago I had the privilege

Werner -

That's why I don't use or recommend "rebuild kits" for rag joints - they are not the same as the original components - they just "do the job"; only the complete assembly is correct to the function and intent of the original design. I don't take any chances with any of my steering systems - it's the wrong place to make do with short-cuts.

Designs varied somewhat in detail over the years, but the rag joint came to the assembly plants as part of the steering gear assembly from Saginaw Steering Gear; they installed it to the input shaft in a fail-safe fixture that centered the sector shaft travel and oriented the splined portion of the rag joint to the input shaft in the straight-ahead position before installation of the clamp bolt. Saginaw also made the steering column assembly, and the upper flange came as part of that unit to the assembly plants; some designs had it welded to the steering shaft, and some had it clamped - in either case, the flange was oriented to the shaft at Saginaw such that the correctly-phased straight-ahead position of the flange coincided with the blind spline and index mark on the steering wheel end of the shaft being at 12 o'clock. That control, plus the error- and mistake-proof design of the rag joint attaching studs and safety studs, ensured that the assembly plants couldn't assemble the system out of phase; the threaded studs wouldn't fit in the wrong size holes in the upper flange, nor would the riveted safety studs.

NASA-level hearing or instrumentation isn't necessary to detect a failing rag joint; after driving a car with a normal joint for any length of time, the clunks, noise and vibration introduced into the steering column by the metal-to-metal contact of a failing joint sends a VERY clear message that something is not right in the steering system.

The issue of the rag joint also serving the function of a U-joint is obvious; dimensional variation of the body and frame, body drop positioning variations, and dynamic relative movement of the body vs. the frame as a result of compliance in the body mount cushions makes a flexible coupling essential. One-piece solid shafts were used for years on C1's and many unibody cars like Corvairs and the original Chevy II, but that was long before designers worried about "spearing" the driver in frontal collisions, and one-piece shaft/columns were a major PITA in the assembly plants at body drop - just ask anyone who has had to remove a '53-'57 column/shaft/gear unit with the body on the car.

And that's the way it was....and is today, except most rag joints have been replaced with rubber-isolated sliding-element enclosed-roller bearing tripot joints, especially with "front-steer" conventional steering linkage or with forward-mounted steering racks, both of which have very long shafts and design angularity through the joint in the system.

[Werner R.]

Re: Twenty Years ago I had the privilege

WELL, THANKS FOR THE RESPONSE. THAT DID MAKE SENSE. I CANNOT BELIEVE THAT ANYONE WOULD WELD THE UPPER COUPLER TO THE STEEERING COLUMN, BUT I'LL TAKE YOUR WORD FOR IT. NOW I GUESS I'VE HEARD OF "EVERYTHING". HAPPY MOTORING.
WERNER
ps i know it seems like we beat this to death, but i'll bet some members, including me, learned somthing useful and interesting.

now, let me ask you about the ....[heh, heh-joke!]

[Eric H.]

My Rag Joint Failed

while I was making a tight turn at the end of my street. There was obviously something wrong with the steering, apparent even at very low speed. Steered it back home without a problem on the "engaged safety prongs".

Ric

[Craig S.]

Re: Twenty Years ago I had the privilege

John - I for one learned a lot from your posts...very helpful!....Craig