Tiller shear bolt.

[rich1010220]

While tilling with my 1610D and 1200 tiller the times quit turning. /forums/images/graemlins/confused.gif I found the shear bolt on the tine shaft broke. A 5/16 bolt fits perfectly and I'm thinking of using a grade 3. Is this the proper thing to do or do I need to get an origional shear pin.

Rich

 

[BrettW]

Rich, can't help you but can you tell me where the bolt goes or is ? I can find mine at all. Do you have a yanmar tiller? thaks, bw

 

[rich1010220]

Brett,
The bolt is on the outout shaft of the chain case right next to where the tines are. I took the bolt to work and tested it on the Rockwell, a grade 3 bolt was almost the same hardness. I put it in and tilled some more tonight. I do like things proper so that is why I'm looking for the correct pin. It is a RS1200 Yanmar tiller.

Rich

 

[Anonymous Poster]

This post makes me think. I need to check my shear pin, and maybe everyone should. I was tilling last weekend when a big rock got jammed in the tines and killed the motor. That shear pin should have sheared, so I'm thinking someone replaced it with something stronger not realizing what it is actually for. Luckily no damage was done but you never know next time.

Mike

 

[GaryK]

Most shear pins on tillers and other PTO equipment are grade two, the bolts with no hash marks on the top. the idea is to destroy the bolt and not equipment. I would not put a #3 in. Are you sure its 5/16, most are 1/2"? Have you thought about putting in a clutch, saves replacing shear pins and is easier on the equipment

 

[rickatom]

I am using a yanmar rs 1300 tiller behind my YM2000 tractor. I am having the same problem with bolt shearing as rich101...... Anyway, I have installed a spring clutch on my pto, and I am still having to replace grade 8 bolts in the tine shaft. I am getting so frustrated with this and dont know why this is happening. I would think the clutch would eliminate the bolt breakage problem. I tried grade 5 bolts and they shear like nothing. When I got the tiller I had to do some reworking. It looked as though the splined shaft had been welded at one time. Wondering should I do this again being I do have the spring clutch.

 

[kenmac]

sounds like the slip clutch isn't working properly. JMO ..I think the clutch should slip B-4 breaking a grade 8 bolt

 

[Roonabeck]

I'd follow this advice to make sure you have the slip clutch adjusted properly: http://www.tractorbynet.com/forums/attachments/218188-slip-clutch-adjustment.html

 

[rickatom]

I just backed all the bolts off and spun the tines. Now starting to re adjust the bolts. Maybe factory paint was holding. Right now it is tighter about 3 threads from the end without slipping.

 

[jonyyuma]

To me,IMHO, YOU MIGHT LOOK INTO THE BEARINGS.. That is a lot of torque to be shearing high grade bolts??