robbiewolfer

So I removed the brake caliper and rotor and trying to disassemble the whole trailing arm. I encountered the spindle hex nut and the cotter pin is completely rotten. I tried taking it out and both ends broke. What is the best way to remove the nut with a busted cotter pin? Do I get a small flat head screwdriver and break off the remaining cotter pin between the spaces in the hex nut?

Gale Banks 80'

If You can get to the Side of it I would drill out the soft Cotter Pin end enough to clear. If You can't get to the Sides I would use a Cold Chisel sharpen'd to the correct width and cut em off.

TimAT

Drilling it out would be the easy way. But if you can't get to it, you might be able to just unscrew the nut. Not very easy to do, but the nut and bolt are tougher than the cotter pin. If it's all that rusty to start with, that might be the only option. And you'll probably replace the hardware anyway.

Indiancreek

If it's that rotten, I'd try an impact gun and see it the remainder of the pin will just shear off. Then when it's apart use a punch to drive the rest out.

roadblock69

That cotter pin is much softer than the nut. Put a heavy wall six point socket on the nut and remove it. The cotter pin will just shear off and you can use a small follow through punch to remove what is left in the shaft. That has never failed me.

Easy Mike

Knock it through with a drift pin or punch.