Metric Man

In my first attempt at servicing a BB I'm doing my old Trek 4300. I removed the crank arms on both sides no problem and got the left BB to come off but the one on the right side won't budge. I assume that it is still a counterclockwise to remove, but I'm wouldn't bet my life on it. Are BB's sometimes almost impossible to remove? Also, I found out that the bearings are sealed so I guess there isn't any real service I can do except clean them up...is that correct? And yes, I do have all the correct tools.

JanMM

Drive side/right side is reverse threaded; turn clockwise to remove. Can be hard to loosen. You may not need to remove it. Was the BB turning smoothly? Is it a cartridge BB?

Metric Man

I'm not sure what cartridge means...it has two sealed bearings inside. I got out the left side, but the right was stuck in behind the BB cover. Removing clockwise doesn't make sense on the right side...but I trust what you are saying. Thanks.

Also there wasn't any problem, I just wanted to lube it.

operator

Your terminology doesn't make any sense. Square taper shimano carts generally aren't serviceable in this manner. Take a picture of the unit or whatever you've already pulled out of the shell.

mechBgon

The 4300s I remember from recent times fit that general description. Wait, just remembered I have a photo of that type... does it look like this one? The silver tube butts up against a steel bearing cartridge at the left end (not visible here)?



If so, the one practical thing you can in there, is to slather grease on the male & female threads of the frame and the bottom-bracket, and lube the interior of the left cup, before you reinstall it. I was building a Trek yesterday that was built bone-dry AND evidently installed using air tools... it took a 4-foot lever to crack the driveside loose. Can't imagine what it would take 10 years down the road once they'd corroded to eachother.

Metric Man

I realize they aren't serviceable now, but I didn't have that knowledge before I got into it, and in the automotive industry, which I am very familiar with, these would be called sealed bearings...if the bike industry calls them cartridges I can go along with that...it's just not a term I am familiar with. My real question was does the right side BB remove in a counterclockwise direction or clockwise?

z415

Here.

Metric Man

Yep, that's the dude. The right side has a butt, or lip on it and the left doesn't. I also noticed that if you tighten it too much it squeezes the "carts" and makes it harder to turn the cranks...now that I know the proper direction I'll give it a big heave ho...maybe I'll break out the impact wrench.

Metric Man

Yes, thanks.

operator

On your bike the right side (drive side) will definitley loosen clockwise.

That bb MUST be tightened to proper torque, regardless of whether it causes more friction/binding issues in the bottom bracket. The reason why it does that is

a) crappy OEM bottom bracket
b) bb shell facing/thread issues

When you're reinstalling that bb

1) Grease shell threads
2) Grease bottom bracket threads
3) Grease the bb body itself where the left cup would contact

Grease VERY generously.

Use copper anti-seize if you don't plan on pulling the unit reguarly (you don't need to do this) and it gets ridden in all weather conditions. This will prevent a future thread entitled "Help, my bb is seized".

Bianchigirll 

my question is why were you servicing your BB? was it lose or making noise? IMHO BBs and headsets should not be routinely taken apart for routine maint. on a commuter if everything is working fine an annual overhaul is inorder but that is about it.

also on older style "cup and cone" BBs the right cup was calle the FIXED cup and should never be removed unless replacing the bb. I do the same with the cartridge style too.

Metric Man

The bike is 3 years old and was making a clicking sound occasionally so I figured it needed attention. As it turns out a little grease and re-torquing fixed the click. Thanks.

z415

Most definitely use anti-seize.