Help. New XT cranks squeaking / squealing...

[singletrkmind]

I installed a brand new XT crankset a couple of months ago with new BB. When I first installed, I didn't grease the shaft, just the parts indicated on the install sheet from Shimano. After a couple of rides I started hearing a high-pitched, high-frequency squeal. In other words, it sounds like the rhythm of the squeal is faster than the crank is turning (which seems like it might be bearings). I have taken the cranks back out a couple times and greased everywhere to no avail. Anyone seen this before? I think the bearings are sealed so not sure if I can get grease in them.

Any good way to test the bearings that you could suggest?

Thanks.

[keen]

I installed a brand new XT crankset a couple of months ago with new BB. When I first installed, I didn't grease the shaft, just the parts indicated on the install sheet from Shimano. After a couple of rides I started hearing a high-pitched, high-frequency squeal. In other words, it sounds like the rhythm of the squeal is faster than the crank is turning (which seems like it might be bearings). I have taken the cranks back out a couple times and greased everywhere to no avail. Anyone seen this before? I think the bearings are sealed so not sure if I can get grease in them.

Any good way to test the bearings that you could suggest?

Thanks.

Here's how to lube the bearings. I lube new bearings, before use, as factory greasing is sparse : Outboard Bearing Bottom Bracket Service Guide. With Pics.

[SimpleJon]

New bearings shouldnt squeal:
Did you preload the bearings before tightening the non drive side crank arm?
Are you sure it's the crank and not something else? Pedals would be worth checking

If you are sure it is the bb I would probably look to get a warranty replacement

[singletrkmind]

Excellent, thank you!

[Slash5]

Was the bottom bracket faced? Sounds like the bearings may be misaligned.

[goodmojo]

Excellent, thank you!

I have an slx bottom bracket that started squeaking a month after I got my new bike. I took off the cranks and found that the bearings were crunchy on one side. I opened up the cartridge, cleaned the bearings a bit (just by wiping as I turned the cartridge) and put in new grease. They were still a little crunchy but definitely rolled a lot smoother. The most important thing is that they are quiet now. If they burn out in the future, I can use that as an excuse to upgrade. I think they will be fine for long enough though.

Also my bike shop was like the cartridge is not serviceable you need a whole new BB, @ $50 or $75

[eatdrinkride]

I'm guessing pedal squeak. Just drop some oil on the spindles and see if it goes away...or remove the pedals and ride for a while

[Berkley]

I have an slx bottom bracket that started squeaking a month after I got my new bike. I took off the cranks and found that the bearings were crunchy on one side. I opened up the cartridge, cleaned the bearings a bit (just by wiping as I turned the cartridge) and put in new grease. They were still a little crunchy but definitely rolled a lot smoother. The most important thing is that they are quiet now. If they burn out in the future, I can use that as an excuse to upgrade. I think they will be fine for long enough though.

Also my bike shop was like the cartridge is not serviceable you need a whole new BB, @ $50 or $75

Enduro bearings makes sealed bearing replacements designed to press into the stock Shimano BB cups. I've done this on two of my BBs now and they hold up much better. Cheaper too, IIRC the bearings were $15-20. And less wasteful :-)

[singletrkmind]

Was the bottom bracket faced? Sounds like the bearings may be misaligned.

What do you mean by "was the BB faced"?

[singletrkmind]

OK, I just looked it up. The old BB that was on there did not make any noise, that was one that I replaced a few years ago because the factory Truvativ one got "crunchy". Do you need to have the BB re-faced each time you install new BB cups?

[eatdrinkride]

Do you need to have the BB re-faced each time you install new BB cups?

No.