Engine belt pulley on 3511

[quinny]

I am having problem with Zetor 3511, engine belt pulley below fan belt.The pulley keeps slipping off, the nut (starting claw) will not tighten on shaft, what should i do ?,

 

[dave_peters]

I'm not familiar with the setup on the front of the crank, Does the nut not tighten up onto the pulley?, in which case a washer behind the nut will firm it up. Most other tractors have a lock washer that has turn up tabs to stop the nut undoing, maybe you can use something like this. Use Loctite on the nut when its done up firmly.
Dave

 

[quinny]

Thanks Dave P, nut does not tighten on crank,thread seems to be worn, will try what u said.

 

[dave_peters]

If The thread is worn and the nut slips on the threads you have more of a problem. you could try a new nut, carefully so as not to strip it, liberally painted with loctite studfix or similar. If you are not using a starting handle on the dog there shouldn't be too much stress provided the pulley is snug on the crank and its key is not worn. It may be a good idea to remove the pulley, clean it thoroughly with a solvent like brake cleaner and loctite the pulley as well
Dave