Near Failure - Driveshaft Bolt
 

I'm pretty sure this should have been a spirol pin, but it was a Gr.5 bolt instead. I don't know how long it was in there for sure since this is off my donor 126. This shaft had a lot of wobble when I watched it through the holes in the frame. I hope it's just the coupler that is wallowed, and the input shaft of the tranny isn't too bad.

http://i43.photobucket.com/albums/e3...BoltMedium.jpg

Jim:

IIRC, I think that should be a solid metal dowel pin in the drive shaft.

Maybe some of the Gear Drive guys can chime in on this.

Nope, spirol pin, just like the hydros.

I've had two tractors with the steering columns destroyed because someone let the drive shaft go. One was a PS unit.

Scott

My 122 has no choice but to use a grade 8 bolt to hold the drive shaft coupler together. It will not hold using a spiral pin. Suppose she's a little worn, but that was what held it together when I bought it.

Not hold because they fall out, or because they break? If it's falling out, you need to safety wire it so it can't. A grade 8 bolt is going to destroy the coupler and input shaft on the trans.

I gotta agree with Matt, a grade 8 bolt is too hard... If you absolutely have to use a bolt, I believe a bolt that is softer than the the metal in the coupler and the input shaft would be best. Just be sure to replace it once in awhile before it gets very worn.

A better idea yet, may be to try to get a metric spirol pin that will fit the worn holes, I believe Mcmaster Carr has them for a reasonable price.

Sam, McMaster has M6 and M8 pins. M6 is slightly smaller than 1/4". M8 is so close to 5/16 it almost doesn't matter. Jumping from 3/8 to 10mm would work for my loose steering though!
Jim

I replaced the Po's bolt with a spiral and got half a swipe of my yard moved before it spit it out. It's not breaking them, just throwing them out. I can see where the softer bolt would be better. I have Mc master Carr on my book marks maybe I will try a metric spiral pin. That little pin such a headache to put in on that narrow frame tractor though. I do have my clutch patrts here so I will be tearing into anyway this spring.

You can also safety-wire the spirol pin in so it doesn't fall out.