Steering shaft/u-joint/phasing curiosity

69427

69427

The Artist formerly known as Turbo84
Joined
Mar 30, 2008
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Clinging to my guns and religion in KCMO.
Got a question about my steering shaft between the column and the rack. U-joint operations make sense when the various angles are equal and complementary (like a transmission and differential), but the rack "input" shaft and the steering column are in different planes and angles. In addition, unlike the sliding splines of the transmission output yoke, there's set screws for each side of the two u-joints to prevent movement. I'm curious if I'm overthinking (or probably underthinking) things here. I haven't felt any binding when I turn the steering wheel, but I keep wondering if there's supposed to be some small sliding/length adjustment when the two u-joints are always turning at different angles.

Help me clear up the fog here.
Thanks.
 
All I can say is that on my rack install winter 01-02 I used junkyard parts, primarily from a Lumina van.....plus others in a bucket full, I know, hard to describe...but the intermediate shaft was a DD arrangement, with a coupling/rubber disc in there, I went with it so to get the precise length for it by letting it settle in place, then had a buddy weld it so not to slide/give on the length....the two joints are not anywhere near the same angle....never gave it a second thought....never felt anything at the wheel either.....engine running/assisted, or occasionally not......

:clobbered:
 
So you have a ujoint from the steering rack to an intermediate shaft and then another from the intermediate shaft to the steering column? I have noticed that early C4's (using a similar configuration) used a solid intermediate shaft but later C4 use a splined intermediate shaft. I had always assumed it was due to the airbag eliminating the collapsible column.
 
BBShark said:
So you have a ujoint from the steering rack to an intermediate shaft and then another from the intermediate shaft to the steering column? I have noticed that early C4's (using a similar configuration) used a solid intermediate shaft but later C4 use a splined intermediate shaft. I had always assumed it was due to the airbag eliminating the collapsible column.
Click to expand...

Yeah, a single intermediate shaft with u-joints on each end (rack and column points).

The only thing that calms me somewhat on this issue is that the centers of each u-joint (the center of the X) should always remain in the same position in space, therefore the distance between the two centers remains the same.
 
Considered a double U Joint in the middle?
126955702ecc0d3b6.jpg

Or use Heims to hold the shaft "In Space?"
1269557030d79fe5b.jpg

I'm getting close to that point - firewall should be folded today - and those are options I'm thinking through.

Cheers - Jim
 
69427 said:
Got a question about my steering shaft between the column and the rack. U-joint operations make sense when the various angles are equal and complementary (like a transmission and differential),
Click to expand...

The equal angles for a rotating shaft is so the differential does not get a small cyclic torque variation. Since the rotation is fast, you get lots of cycles and possibly high cycle fatigue. On steering it probably is so small and such low cycles it is not an issue.
 
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