Loose bolt on left crank arm

[DaveM]

(07-01-2012, 01:49 PM)adarg Wrote:  o I hit the crank arm with a hammer in place.

This may help seat the crank arm properly. However, it may also damage the bearings/races. Generally not a good idea to hammer on bearings. FYI

[nfmisso]

(07-01-2012, 01:49 PM)adarg Wrote:  Hi everybody.

I had the same problem mentioned here- that the crank arm kept falling off. I tried something today and maybe it can help you guys as well: I made sure that the square shaft's stem does not touch anything on the crank arm, so I hit the crank arm with a hammer in place. In doing that I tried to achieve a snug fit between the square shaft and the crank arm. After doing so I closed the nut tightly.
I will report if the crank arm holds in place.

Adar;

Great way to damage the bearings......

[spanner_152]

Hi all. I have a 2007 diamondback dirt jump bike. And I am having same problem with the none drive side crank arm making a "clinking" sort of noise when I peddle, I have tried changing the bolt & it just still keeps coming loose & if it goes tight the piece of plastic thats like a washer on the bolt doesn't sit properly. I've tried tighening it etc and nothing will work.. Has anyone any suggestions I can try? Ie replace the BB if that could be the problem ? Thanks.

[nfmisso]

(01-03-2015, 01:25 AM)spanner_152 Wrote:  Hi all. I have a 2007 diamondback dirt jump bike. And I am having same problem with the none drive side crank arm making a "clinking" sort of noise when I peddle, I have tried changing the bolt & it just still keeps coming loose & if it goes tight the piece of plastic thats like a washer on the bolt doesn't sit properly. I've tried tighening it etc and nothing will work.. Has anyone any suggestions I can try? Ie replace the BB if that could be the problem ? Thanks.

There should not be a piece of plastic like a washer on the bolt. The load path should be all metal. Pictures required.

It is more likely the left crank arm became loose, developed wear and now needs to be replaced. The BB axle is hardened steel, the crank arm is generally aluminum.

[spanner_152]

Hi sorry for not being descriptive, it is a "m8" bolt if that's any more use? It looks to be as if there is something missing behind were the crank arm goes sometimes I can get the bolt to tighten but other times it just comes loose within minutes of riding. I will post pics up soon as I get chance.