Best way to remove midshaft coupler

[Waternut]

I've heard a lot of people say to heat the coupler to aid in removal but how do you keep it from spinning? I saw one person say a pipe wrench but I can just see that gouging the piss out of it.

 

[Matt_E]

You use an old pump shaft or the actual tool (splined end just like the pump shaft)

 

[Motorheads5]

You can grab the shaft in a vise beyond the seal and bearing surface closer to the coupling. That way you will not scar up the seal surface, then heat it up and it will come right off with a large pair of channelok pliers or a pipe wrench, I have a chain wrench I like to use if you have one, use that.