Heavy Clunk "Farmall A" Please Help!

Mon Aug 18, 2008 2:19 am

Hi All,

I just bought a 45 Farmall A, not for any other reason other than I liked the look of it and to give me another excuse to play in the shed (I mean I know nothing about early tractors). It does need alot of work but is complete minus the rear rims and centers (has 10 stud truck rims). My possibly silly question is when cranking with the crank handle (no elec starter) there is a heavy clunk coming from the engine, it sounds like something is hitting the inside of the crank case loud!. I have had the sump and rocker covers off and everything is intact just minor rust on rocker gear from condensation. Is this normal noise normal and what is it or does it sound more sinister?

Thanks, Tristan

Re: Heavy Clunk "Farmall A" Please Help!

Mon Aug 18, 2008 8:44 am

That is one of those things that is hard to diagnose without hearing it, but I do have a couple questions. Is it once per round, once every other round, or twice per round? If it is twice per round, just as it builds compression, it may be the magneto impulse tripping ( assuming it still has a mag rather than a distributor), which would be normal. Most people describe it as more of a snap or clack than a thud though. If that is not it, no, it is normal and needs to be seen to.

Re: Heavy Clunk "Farmall A" Please Help!

Mon Aug 18, 2008 8:52 am

The other question I have is do you feel anything when it goes "clunk"?

Re: Heavy Clunk "Farmall A" Please Help!

Tue Aug 19, 2008 3:02 am

Hi Again,

Had a little more of a look today, it would appear to be the mag' but hell that is the loudest mag' i've ever heard. Are A's renowned for having loud magneto's? Anyway it's not working so it will be coming off, possably the reason it's not going.

Thanks for those reply's; by the way it occures twice every full crank.