Befco tiller problem

[Kalka]

Hello gentlemen I need little help with my old Befco 42 inch chain driven tiller. I recently opened up the chain drive to clean this area and refill the chain case with lubricant. To my surprise the shop that worked on it few years ago filled it with dry lube. Any way once I cleaned it all up I find that the chain in the lower sprocket is not fully seated and is actually damaging the sprocket teeth. can somebody direct me as to how to set chain back on the sprocket squarely.
thanks,
kalka

 

[Kalka]

 

[Yander]

Slide the sprocket off the shaft (Probably has as set screw you will see if you clean it up), put the chain back on and slide it back on the shaft. If the sprocket is too chewed up get a new one before putting it back on.

I would also clean that chain up with some diesel fuel and let it dry and relube everything with gear oil in the case.

 

[Kalka]

Thanks for the replies. Sorry for the delay . Family issues came up. How do I relieve the tension on the chain to remove the sprockets to fix this problem ?

 

[Harry in Ky]

Is there not an idler sprocket a little farther up that's not included in your photo? Most arrangements like that have one. Loosen up an adjustment bolt and the idler will move away from the chain and allow more movement.

 

[mikester]

Is that the correct chain and sprocket combination? Photo kinda looks like the chain was replaced with one of a different pitch.

 

[Kalka]

I have had this tiller for 25 yrs. Bought it second hand. This is the chain it came with. The chain is not meshed properly with the sprocket. That is what I am trying to fix.

 

[ericm979]

While it does look like the chain and sprocket are of different pitch, I think the wear on the sprocket would be a lot worse if it'd been run for long like that.

I think what's happened is that the chain is derailling and is riding up on the side plates. To fix this you need to release tension on the chain, fit it properly to the sprockets and then put tension back on. I think it might have ridden up because the sprockets are not perfectly parallel and the chain got loose. Roller chain can handle some amount of misalignment between sprockets but its more likely to derail.

 

[Kalka]

That is what I am trying to do. How do I release the tension on the chain? I released the spring holding the tensioner but nothing happened. So I guess I will have to get the sprockets off along with chain and try to reset it as mentioned above.

 

[workinonit]

You got a pic of the tensioner?

 

[Kalka]

Here it is.

 

[Sawyer Rob]

Check to see if that bottom sprocket isn't on backwards... OR needs to be shimmed out for proper alignment. OR the top sprocket is too far out, I can't tell from the picture.

SR

 

[Kalka]

Here it is.

 

[Kalka]

Will try. Thanks.

 

[Kalka]

Only problem is that I can’t seem to budge any thing. The chain is under lot of tension and tensioner is is stuck in present positio and I can’t loosen it.

 

[Sawyer Rob]

Looking better I see, that top sprocket is held on by a C clip, so I bet the bottom one had one too.

Spray everything with a good penetrant, that bottom sprocket should move back and forth on the shaft. Push it on and C clip it in place.

EVERYTHING needs to be freed up! That dry lube didn't do you any favors.

SR

 

[ericm979]

It looks like the tensioner is up against a hard stop- that bolt looking thing on the lower left side of the tensioner arm. You could try to remove that to let the tensioner come back some but if it's threaded into the body of the mower and there's a lot of tension on it, removing it might damage the threads. With the chain under tension you probably can't remove the sprockets.

You should probably replace the chain and probably the sprockets. I think the chain is worn so much that the tensioner could not keep it tensioned and that's why it derailed. Also that master clip is near to falling off! The sprockets don't look too bad. I think the dry lube was not appropriate and that made the chain wear out.

The usual measure for chain stretch is to pull it tight and measure some distance between the pins. Most chain has the pin to pin distance as some fraction of an inch making it easy to check with an SAE ruler. For example bicycle chain should not be stretched more than 1/8" over 1 foot. I dont' know the values for industrial chain like this.

If you're going to replace the chain, then the easy way to get it off would be to cut it with an angle grinder.

Industrial roller chain is sized in pitch (pin to pin distance) and width. When I have replaced it I found tables on line of the common sizes and matched mine up. It was not hard to do. Cut it by grinding off rivet heads and pushing the pins out. Cut a section with an inner link on each end and connect with a master link. Size the length by counting the outer links on the original (a full link is one inner and one outer).

 

[Gregster613]

I'm certainly no expert but it also looks as if you could shorten the chain one or two links. Then "maybe" the tensioner will be able to do its job. The master is right there with a loose clip on it.

 

[Sawyer Rob]

IF, that chain has stretched so much that it needs shortened, then it needs replaced, not shortened.

Stretched chain ruins sprockets...

SR

 

[ericm979]

When a chain has worn a lot, it wears the sprockets faster. Industrial chain is pretty inexpensive.