Shaft coupling castle nut

[Skram]

I replaced my shaft seal today which overall went well. But when I went to tighten down the castle nut on the shaft at the coupling, if I tightened it down all the way the holes were blocked and I couldn’t get the cotter pin through. I had to back it off to where it was basically just finger tight to be able to get the pin in. Is this ok or do I need to try to readjust so the nut is tight when I put in the pin? I counted the exposed threads on the shaft before removing and after installing and they appeared to be the same. I think it’s that I drove the shaft into the coupling a little more then it was, rather than the shaft not being in far enough. It’s a 2007 X30.

[waterlogged882]

I replaced my shaft seal today which overall went well. But when I went to tighten down the castle nut on the shaft at the coupling, if I tightened it down all the way the holes were blocked and I couldn’t get the cotter pin through. I had to back it off to where it was basically just finger tight to be able to get the pin in. Is this ok or do I need to try to readjust so the nut is tight when I put in the pin? I counted the exposed threads on the shaft before removing and after installing and they appeared to be the same. I think it’s that I drove the shaft into the coupling a little more then it was, rather than the shaft not being in far enough. It’s a 2007 X30.

You're good.

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[gwozhog]

Your splines on the coupling and shaft are worn out and that is why it’s driving in to far. If you install a new coupling on a worn shaft it will wear premature too and that is why nobody sells splined driveshaft couplings with out buying the entire driveshaft too. You might want to install a washer to see if that will help because a finger tight castle nut is not good especially when you are in reverse.

[etduc]

^^^^
What he said. The prop would move back and forth. Diagnosis of this is a thump, when putting in gear. The prop can, loosen the prop nut. That's why you always use a new cotter pin. ( I believe, the torque amount is: 40-45 ft;lbs)

[waterlogged882]

The characteristic of a castle nut...use it to secure the prop then find the closest position (forward or backward...usually the later) to insert the cotter pin. The shaft position is irrelevant unless it is in a bad way. The castle nut still finds its home at the nearest hole and slot alignment for the pin.

The Ny-lok nut is a different application.

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[Skram]

Just to clarify, I am referring to the nut on the coupling side at the transmission, not the prop nut. I do think I like the idea of adding the washer to get it tight.

[waterlogged882]

Just to clarify, I am referring to the nut on the coupling side at the transmission, not the prop nut. I do think I like the idea of adding the washer to get it tight.

Sorry to have misinterpreted. That (photo above) is the only castle nut that I know.

You did say shaft/coupler...

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