Yardvacuum Impeller Removal

[l008com]

So I watched a bunch of youtube videos for removing the impeller off my machine. This is so I can ultimately take the motor off and open it up because I think it overheated and melted it's camshaft. But anyway....

Multiple videos say to use a 7/16" - 20 bolt. So I go pick one up and when I go to thread it in, nada. Totally the wrong threading, although the diameter seems right.

So what's going on here? Did I buy a bolt with the wrong threading? Certainly possible someone could have put it in the wrong spot on the nut and bolt wall at the hardware store. Easy enough to check if someone can tell me what the " - 20" is. Is that like threads per inch or theads per something?

OR does my impeller just need something other than - 20 threading? Unfortunately you need this bolt to remove the impeller so I can't just bring it into the hardware store and try every size until I find one that works - which is what I normally do in a situation like this

BUT I do have a picture, maybe you guys can tell just by looking?


Assuming the "20" is the threads-per-inch, it looks like I have 19 threads per inch here. I assume that missing thread is just the perspective of the camera. So it is a -20 bolt, so I guess I need something else you think?


Oh also here's the model number(s) off the machine itself:
24A-070J799
247.77013.0

And the serial number is:
1H198G70100

 

[ILENGINE]

I have found a few references to spindle removal tool for MTD products

https://www.amazon.com/deawater-753-0900-753-0638-759-0638-Craftsman/dp/B0BXMTG7SB

 

[l008com]

I don't need the whole tool. I just need a simple short bolt to thread i to teh impeller. I can use a piece of rod or something else to be the "insert" it pushes against. Plus the reviews on that thing to not look good. And it looks like there are more than one threading these impellers have so it all leads back to the same question, which size threading am I looking for. I guess I forgot to include my machine model number in the original post.

 

[ILENGINE]

Went and measures the threads on my DR impeller removal tool and they are 20/inch. but it measures .327 in diameter which is smaller than 7/16 but doesn't match up with anything else. From the picture it looks like the threads in your impeller are damaged so they could be flattened causing issues with your bolt.

 

[l008com]

Yeah I don't get it, 7/16-20 is what this bolt is and the threads aren't right at all. YOu have to go through the impeller threads to get to the crankshaft threads so I'm nowhere near those.

 

[StarTech]

The tool pushes the impeller off so it is design to pass the 3/8-24 threading of crankshaft and bottom out in the blind hole. This prevents the tool from pushing on the end of crankshaft damaging the threads.

Matter of fact any puller that pushes against a shaft should have a sacrificial intermediate block (shaft protectors) as even those pullers can also damage threading without these. They also help prevent the shaft that being press against from flaring.

Here is an example of one in use.

 

[l008com]

Yeah but what I'm saying is that I can't get this bolt to thread into the initial threads that it is supposed to engage with. Once I can get it to engage, I can throw any old rod in the hole to act as a spacer/pusher so I don't to any damage to the threads on the motor shaft. But I can't do that until I get a bolt that will actually thread in to the impeller, which seems to be my problem. When I started to thread this bolt in, it got a few turns in but it was getting tighter and tighter until it basically stopped. It's gotta be a case of the wrong threading.

 

[ILENGINE]

Could it be metric thread.

 

[l008com]

I guess, it could be.

 

[StarTech]

Sounds like it is a M11-1.25 thread very close to 7/16-20 but is tight two ways. 7/16-20 are drilled out at .390 and M11-1.25 is drilled out at .384 and the pitch are slightly different too. Looks the same but are not.

It will nearly impossible to find a M11-1.25 screw.