Noise from crankshaft spindle and pedal falls off

[mm391]

Hi,

IN the last 6 months I have been getting really bad noises, creeks, clunks etc coming from somewhere around the spindle connecting to the crankshaft. Every time I put pressure down on the left hand pedal, either it or the spindle attaching to the peddle creeks, clunks real loud and the the pedal works itself loose. I have tightened it up every time and after a couple f days it becomes loose and almost falls off again. Can anyone help explain why and how I may fix it myself?

Thanks

MM

[mm391]

(05-26-2012, 05:06 PM)mm391 Wrote:  Hi,

IN the last 6 months I have been getting really bad noises, creeks, clunks etc coming from somewhere around the spindle connecting to the crankshaft. Every time I put pressure down on the left hand pedal, either it or the spindle attaching to the peddle creeks, clunks real loud and the the pedal works itself loose. I have tightened it up every time and after a couple f days it becomes loose and almost falls off again. Can anyone help explain why and how I may fix it myself?

Thanks

MM

Sorry actually being a bit clearer it is the square taper crank arm that comes away from the spindle. The pedal actually is fine. The bike is an Dawes XC 2.2 and the crank arm has "Truvativ" Powered by SRAM on it.

[JohnV]

The noise could be from the bottom bracket bearings needing cleaning, greasing or replacement. If the taper on the spindle and square on the crank arm look good, the crank arm falling off could be solved with some LockTite on the bolt threads as it appears that they are loosening up as you ride.

[mm391]

Thanks very much. How would I clean the bottom bracket bearings?

[Painkiller]

If it is a cartridge BB you must replace it, if your taper on your crankarm has been deformed you will have to replace it. inspect it closely.
on yours I recommend the non- hardening lock-tite and do not grease the spindle first. If it fails after that get a new crank

[xerxes]

Most bottom brackets are sealed units now, so if it is indeed that the bearings are shot then you would replace the whole unit.

The Shimano UN54 or UN55 are good quality, fairly cheap and they last for ages: http://www.chainreactioncycles.com/Models.aspx?ModelID=71369&utm_source=Google&utm_medium=Shopping&utm_name=UnitedKingdom

Having said that, creeks and clunks are often as a result of the crank arms not being on the square taper properly. Take them off, clean the square taper and the square hole in the crank arm and re-assemble: http://www.parktool.com/blog/repair-help/crank-installation-and-removal-square-spindle-type, that might solve your problem.

[trevgbb]

crank arm falling off;
this is a persistent problem and has been raised here many times, no amount of cleaning and loctiting will prevent it happening if the square hole in the arm is at all bell mouthed.
see this post as just one example;
http://forums.bikeride.com/thread-4036.html
You need to assess if the noise is caused by loose or damaged bearings in the BB, or is due to the problem with the crank arm.

[saam89]

hi people was just wondering if you could help me with this probblem im having i have have put a vid up soz about the wind you can hear the sound best right at the start

http://www.youtube.com/watch?v=_xUy3OpmDdY

thanks for your time

[Bill]

1. Check pedals first for creaking by putting pressure on them with your foot while stationary.
2. Bottom Bracket loose or needs cleaned.
3. Seat post may make a creak like that.