Friday, September 16, 2011

Creak Abatement Phase Three - plastic bottom bracket cup failure?

Creaky bastard.

I aint a smart man, but I know that the Turner was not engineered to creak. I also know it aint the pivots or the shock bolts, or for that matter the seat post (fairly certain). SO, the search continues.

Post ride inspection yielded this...

Shimano UN-54 bottom bracket cup failure. It is the plastic non drive side cup. Typical for UN-5*, but finding a UN-7* bottom bracket is getting harder and harder to do, so I threw the LX grade unit in there just to get the bike rolling.

The tools... 14mm socket and a wrench, and the trusty Park crank puller. Actually, this is a new Park crank puller, as the old one has flared too much to use. Not so trusty, maybe?

Old and new pullers. Quite a flair on the old one. This is how they wear out.

Twist out the 14mm bolt, check to make sure there isn't a washer in the crank arm still, and then thread in the puller. Twist.

We're fighting creaks here, people. So inspect that crank arm taper after its off the bike. Here the Turbine arm looks perfect.

Splined bottom bracket sup tool. Remember that removing the bottom bracket cups means turning toward the front of the bike on both sides. Drive side is reverse threaded... Unless you're name is Pinarello.

The offending crack. What a cheap POS. Shimano should know better than to make this part from plastic, and I should know better that to buy the LX grade part.

Actually, I own quite a few of them, so I should have known better more than once! Here, like an Arkansas Governor's cigar, the new retainer cup is liberally greased up and ready to go.

Thread it on in...

And snug it up! Next stop, install the arm, and then hopefully enjoy the sounds of silence!


KennyBloggins said...

Hi, saw this post and was wondering, did it fix the creak? I have a UN54 with plastic cup and it looks cracked and i've been having a really annoying creaking noise on my down pedal

utahDOG! said...

It did. There are many causes of creaks in the forward half of the drivetrain though, so your results may vary.