knocking from steering u-joint

[Otter74]

I recently noticed a knocking sound from my steering when I wiggled the wheel to the left (left only) at a standstill with the wheels centered. I had my girlfriend move the wheel while I peered underneath the car and listened, and isolated it to the steering rack area. Pulled the trunk carpet up and opened the smuggler's box cover and aha - the two halves of the U-joint in the smuggler's box are hitting each other. If I pull on the u-joint I can feel and hear a little bit of looseness/play somewhere. (this may or may not be normal, or related - but the knocking I'm hearing is definitely the U-joint hitting itself.)

I did some searching (sorry, the links are opened on my iPad and I'm typing on my laptop) and found a few old threads with helpful information. I may have a worn U-joint that needs to be replaced. If so, how critical is it? Can they be rebuilt, or do they have to be replaced?

The other reasonable possibility that I can see is that there is a worn bearing either in the steering shaft coming out of the rack, or in the steering column or intermediate shaft, either one of which can be allowing just enough play in the shaft location to allow the u-joint to hit itself when you begin to turn the wheel to the left.

Which of these is more likely, based on experience? Is there something else that I'm not thinking of? I saw in an older thread that the lower steering column support bearing is a n open ball bearing with a loose press fit, but this seems unlikely to me as a root cause. The steering rack was rebuilt maybe 5 years ago by the previous owner.

I took a photo of it to attach here, but for some damn reason I am unable to email it to myself. I'll add it when I can.

thanks,
David

[DRACO A5OG]

Place a vice grip on the shafts below and above the U joints, if there is slop, you need to replace it. Changed mine last year, trued to put a good used one but that too soon got sloppy.

While you are there, take a closer look at the Donut Needle bearing under the clamp holding down the lower steering shaft.

[Otter74]

Originally Posted by DRACO A5OG

Place a vice grip on the shafts below and above the U joints, if there is slop, you need to replace it. Changed mine last year, trued to put a good used one but that too soon got sloppy.

While you are there, take a closer look at the Donut Needle bearing under the clamp holding down the lower steering shaft.

Thanks, I'll check that. I assume that the clamp (and needle bearing) you refer to us the one shown in the photo. There appears to be a little bit of radial play in the lower steering shaft - maybe 1-2mm at the splines, I'd guess.

[steely]

I could be wrong, but from the picture that U-joint doesn't look to be stock.
What does the one upstream look like?
My 87 uses 930-347-025-01, and from Pelican that part is compatible back to 74. (even maybe earlier)
Can you post your MY (maybe include it in your signature)?

[steely]

Here's just a partial shot of mine, an the clamps are solid, not rolled:

[DRACO A5OG]

OP 's is OEM yours is the superceded one.

I originally had OP's and when I ordered the new one yours arrived .

Yes, OP, that is the lower shaft needle bearing. So with the Vice grip on top and bottom did the U joint show slop? Of course it is easier to remove and check for slop but hate for you to remove and lose your alignment but if you rotate like Steely and remove, you will keep the alignment intact. Just note wheel and steering wheel positions.

[Otter74]

Originally Posted by DRACO A5OG

Place a vice grip on the shafts below and above the U joints, if there is slop, you need to replace it. Changed mine last year, trued to put a good used one but that too soon got sloppy.

I did this, and there is a *little* bit of play in the U-joint. I don't have a known-good joint for reference, but the amount of play is not what I'd subjectively call large. I can't seem to get any play out of the lower steering shaft coming out of the rack beyond that which appears to be designed in by the presence of the donut, which suggests the neede bearing is fine, though I did not disassemble anything. If I replace the U-joint I suppose I'd repack the bearing WIIT.

This suggests a little bit of wear in the U-joint, but at what point (of wear) should I consider this important? There is no untoward clunking in the steering from any other cause, and I don't even notice it if I am driving.