JD68 rear axle drive pin

[Tlakulevich]

Hello
I have a John Deere model 68. 20 years ago a shear pin or drive pin broke at the rear axle, preventing the mower from moving, either forward or reverse. I ended up looking at a repair manual to see how to replace the pin ( I do remember the pin cost 30 cents). It seems like the same thing happened today. The engine still runs, the mower still engages, it just doesn't move. I've looked underneath and can see the belt spinning, the shaft spinning, but the rear axle doesn't move. Am I even looking at the right spot? I can't see where a drive pin would go. Any help would be appreciated.

 

[DaveTN]

Some of those pulleys on top of the transaxle in the rear have half-moon keys rather than pins. I've had several partially shear,on Craftsman front and rear engines and wallow out and ruin the pulley if they keep spinning. As a last resort, you may have to pull the transmission/transaxle to get to the pulley, which is usually held on with a snap ring. But with the pulley and shaft spinning you could have an internal transmission problem. One other thought before you go into the tranny. Did you take one of the rear wheels off? There's a key on the shaft to hold the wheels in place. If it fell out that would cause the same condition. Sorry I couldn't help further.

 

[srekins]

This axle has a 3/16 x 1 inch groove pin. It goes through two parts of the axle. You can lift the rear of the mower and see the hole on the axle about 8 inches from the inside of the right tire. You have to line up the hole of an inner axle part with the outer hole and tap this groove pin in there.

We are having the same problem, but now, knowing HOW to replace the pin, we wonder WHY it keeps breaking. We love the mower, but it only runs for a while when the pin breaks. It seems that when we hit un-even ground, that it puts a sort of 'lag' in the movement of the axle and this causes friction that after a few times, breaks this pin. I am wondering if it is due to wear in the axle where the two outer parts of the axle come together.

I do have an assy. of this axle if you are interested. Email with 68 AXLE ASSY. in the subject line if you would like to see it to: Sheilarenee1959@yahoo.com

Good Luck