Shimano cartridge BB lateral play

[icepick_trotsky]

I just installed a UN-54 for a square taper crankset. There is a small but noticeable amount of lateral play in the cranks, like the spindle is moving left and right on the bearings within the cartridge. The cups are snug.

What gives? Did I muck up the install or is it defective?

[Rob1519]

Try removing the cranks and reinstalling at a different position on the BB. Sometimes there will be a better interface between crank and BB.

If you can feel play in the BB without cranks attached, could be a bad unit

[oldpotatoe]

I just installed a UN-54 for a square taper crankset. There is a small but noticeable amount of lateral play in the cranks, like the spindle is moving left and right on the bearings within the cartridge. The cups are snug.

What gives? Did I muck up the install or is it defective?

Feel play with cranks off? Cups tight? Defective or worn out if not new.

[mtechnica]

I'm pretty sure it shouldn't have any play at all, none of mine ever have and I've had quite a few un54 and un55. A couple have squeaked and it went away though.

[11.4]

Lateral play as in the crank arms and the spindle are all moving side to side?

Is it a new bottom bracket?

Two possibilities: the cartridge has play internally, or the cartridge isn't mounted properly so the whole cartridge is shifting. I'm guessing the latter. They sometimes take a bit of wiggling to get them in position correctly before you tighten up. Try that again.

If the play is not in the spindle itself, I'd consider the crank arms suspect. Are they old with deformed splines? Or older cranks rarely had perfectly machined splines and as someone suggested above, you had to try a different orientation of the cranks on the axle to find one that worked better. Square splines were the devil's progeny and while I use them from time to time on the track, I'm happy we've moved past them. At least in a square spline, stick with Shimano or Campy (who weren't that good but at least consistent). If you had Zeus, Suntour, early Sugino, and so on, you never knew what you had.

[Billybob62]

Is it an old Raleigh frame with a 71mm bb shell?

[icepick_trotsky]

The play is definitely in the spindle, not the crankarms. I.e. both cranks move when I push on one. The whole 3 piece assembly moves back and forth. So I don't think the issue is in the tapers/cranks.

For reference, they are Shimano 600 cranks (62xx), and the BB unit is new fresh out of the box.

I'll pull them off and try reinstalling the whole thing, then report back.

[icepick_trotsky]

In case you were wondering, I removed the drive side crank arm, torqued the living daylights out of the drive side BB cup, reinstalled the crank arm, and viola, problem solved.