Mud Buddy 18 Mini, has a worn 10x8 on it I want to replace, I removed the end nut with an impact wrench (that was easy) and now I see it is a threaded prop on the threaded shaft, it looks like it's supposed to just screw off, but it is stuck on good, any tips on how I'm supposed to remove the thing??? Thanks!

By the way, the Mud Buddy "prop removal" page seems to deal with a completely different setup. It looks like my prop is just on a threaded shaft, there's no nut behind it, just the bearing thing that does not turn with the prop.

Here's some pics. As you can see, the old prop is destroyed by my hammering on the blades with a sledgehammer. I tried Liquid Wrench, then heat. No movement. Yes I've been hitting it the right way to UN-screw it from the shaft.







Short of taking a grinder with a cutting wheel to it to cut a slot along the length of the prop before whacking on it again, I'm at a loss.

I can see now why Mud Buddy went with a hex shaft later on.

Ideas as to what else to try?

Prop wrench works well. You can also use a rubber hammer.

OK WHoDat, I'll bite. What is a "prop wrench" supposed to do? What is it supposed to hold, the prop? If it's holding the prop, what am I supposed to turn, the shaft? How do I turn the shaft? All I have to grab is about an inch and a half of threaded end.

I thought about getting a couple of nuts jammed together on the stub of the shaft and holding the prop immobilized with the 2x6 & rope method, but I figure a lot more force more likely to break it free would be generated by slamming the prop with a sledgehammer. But I will try the jam nut method next I suppose.

just to be sure, you say you have been attempting to turn it the correct direction. i beleave it is left hand thread? so you have been going to the right, right?

PB Blaster....and LOTS of it. Let it soak overnight.

While you're waiting on the PB Blaster to soak into the threads, read this thread:

viewtopic.php?f=41&t=44986

"Left" and "right" are relative depending on your vantage point. If you're looking at the back of the boat and motor from a position directly behind it, the propeller and shaft turns counterclockwise, which we'll call "left." The threads on the shaft are such that the propeller is continually trying to screw down tight onto the shaft, not unscrew and fall off. In other words, if you were to hold the propeller tight in your hands and placed it on the threaded shaft with the motor running, it would catch the threads and quickly tighten all the way down and snug up just before it tore your hands apart. The part of the prop that would put pressure on your hands would be the leading edges.

So to UNscrew the prop from the shaft, force needs to be applied in the opposite direction--the trailing edge of the prop.

If you look at the pics closely you can see the pitch of the thread on the shaft. It's clear that when the big rounded trailing edges of the blade are whacked it wants to make the prop turn in the direction to UNscrew it from the shaft.

BluShamu I looked at that thread at the link and am confused. Some of the pics show a threaded prop, and I see the piece of wood between the blades to make it immobile, but I can't figure out how that would help my situation. In other words, I can't see how making my prop immobile is going to matter. Let's say I make it immobile. NOW what do I do? What do I turn, and how? Please look at the pics I posted and describe what I'm supposed to do assuming I've made my prop immobile. Thanks.

You use the 2x4 for leverage to unscrew the prop....not to make it immobile.

Another guy uses an axe handle.

I dont think its the leverage that is in question here fellas - when he has a prop wrench on it - what stops the shaft from spinning while hes trying to torque on it?

Just pull the shaft /prop and replace both if you can't get it off.

Bring the flame wrench (torch) to the party and heat the prop up. It'll swell and you can use the 2x4, flat bar, or whatever you have to unscrew it. Good time to replace the seals while you're in there, especially if you bring some heat to the prop. Good luck.

Yes ^ but it seems like there is nothing to stop the shaft from moving when he goes to torque on the prop. It spins the shaft.

How do you get a threaded prop off if the shaft spins?

How do you immobilize the shaft iot create enough leverage to remove it??

There is no bushing behind the bearing housing to keep the shaft from moving.

Grind down two nuts and put the on the shaft to use as jam nuts. Then he can hold backup with an box end

Slide a pipe over the box end and let it hit the concrete. Then beat the prop

Ted....is the prop stuck on the shaft? Or, can you not stop the shaft from spinning while you are trying to get the prop off?

He has two options to stop the shaft from spinning.

Either remove the clutch cover and find a way to stop the spinning up there. (PD has a slot and a hole to wedge a 3/8" diameter bolt to stop the shaft from spinning in the clutch area)

Or, he can remove the outdrive and put the other end of the shaft in a bind to get the prop off.

Seems like a pita if thats the case. ..

Page 20 of this .pdf link shows how PD has a hole stop. I perused MB's site and couldn't find any maintenance information.

Here's a link to a MB page with some info:

Is this what they are calling the "forward prop nut?" I thought it was something to do with your seal. If that thing turns when you turn the prop....by all means put a pipe wrench on it!

DSC06849.jpg

What kibb said and use some heat.

What kibb said would work if there was more room on the shaft.

@blueshamu - there is no forward prop nut. Thats the bearing housing.

Seems like a crappy setup.

Looked at the mb website

What they show for a stuck prop - not the same setup for above pics.

There is nothing there to hold to stop the shaft from spinning while you are trying to remove the prop.

To answer some of the questions above, Buzz Killington has it right--the bearing housing just in front of the prop does not spin with the prop, and there's nothing to stop the shaft from spinning when you turn the prop. And yes, it is a crappy setup, and I think it is exactly why Mud Buddy went with a hex shaft design later. If this was a hex shaft, I would have had the prop off in 5 minutes.

I will say that even though you can't turn the prop without the shaft spinning, there's a lot of resistance when you slam the prop blade with a hammer. You can get some good licks on it that SHOULD have broken it free given those coarse threads, but I imagine that prop has been on since 2008, or if it was replaced, the threads weren't cleaned & greased before reinstallation/replacement.

I am going to try to cut a slot in the body of the prop along its length as close to the shaft as I dare, spray some PB Blaster on it, let it soak a while, and then whack away again. It WILL come off, it's just a matter of how much of an epic project it has to be. And HOPEFULLY I haven't already bent the shaft or damaged something else $pendy.

I just want to get the thing off so I can order a new prop. Given that it was a 10x8, which is now a 9-1/2 x 8, and given that a new prop would seem to come very close to hitting the splash guard, I am not sure an 11x10 is the thing to get. I bet a new non-worn 10x8 might push my boat just fine, and not lug the engine too much like a larger prop might. Oh well for now the dang thing needs to come off, first things first, I'll deal with size options later.

When ya do get it off put a 3/4 10 nut on before the new prop this will help next time. It will come off ya just have to beat the hell out of it. Dont cut the prop.

Last one I did for my buddy I had to slice prop with a cutting wheel and then drive a cold chisel into the cut. Came off nice and easy, now I go over couple times a year and break it loose.

I also thought someone made a tool that fit a impact gun to take these off.

Goose Crumpler, it seems you have traveled the road I am now on.

And man would it be nice to have some sort of tool that an air impact wrench would fit on.

Man this is horse sh*t

What a weird way to mount the prop.

Well, best of luck bud - subscribed - I want to see what you come up with.

All the best.

I worked on the prop removal project last night and took photos as it progressed.

Here's one of the prop after grinding and cold chiseling (supported by 2x4 underneath) and soaking with PB Blaster and even heating with a propane torch. It still Would. Not. Come. Off.

[imghttp://i1234.photobucket.com/albums/ff419/Tektremis/Mudbuddy/DSC06859.jpg][/img]


More grinding. More soaking. Still ZERO MOVEMENT. Oh yeah this pic shows the OTHER SIDE of the prop that I also ground a groove in. And you may also notice that I cut one of the prop blades off to make things easier to get to and to hammer on to try to spin it off.



At this point, it seemed there was only one thing to do with such a hopelessly lame beast ...



MORE grinding. To get in the tight spaces I had to even use the Dremel with a cutting wheel.

FINALLLY, it gave up the ghost. That SOB would NOT turn off, and in the end it had to be removed IN TWO HALVES off the shaft. As in one half pulled off, then the other. Oh yeah the bearing nut edges got nicked good by the grinders but I believe they are in non-structural areas. Looks like crap but should be OK. But I may want to replace that bearing in there, as the end may have gotten too hot when heating the prop.

Why was this prop so hard in coming off? The only thing I can figure is that those to bunged up threads right where the end nut and prop interface (you can see what I'm talking about in the pics) locked it up. It looks like those threads had come clean off. You couldn't really see it from the outside but it was right next to the shaft where it protruded from the prop. Maybe someone had overtightened the end nut? Those pieces of loose steel in the threads may well have locked it up.













Well I can say I'm very glad that this ridiculously difficult job is over. Thankfully the shaft is not bent. Hopefully I haven't bent or shaken anything else loose inside the engine or drive with all that banging. Hopefully the sealed or grease in that thrust bearing that the prop rests against didn't get burnt out.

So now it's time to order a new prop. 10x8, or 11x10? Remember it's only an 18 horse. Someone said if your prop's too big for your motor, it will lug and wear out the motor a lot faster than a smaller correctly sized one will. Everyone still say 11x10? Micah at Mud Buddy did, but then he also said I had a hex shaft.

Here's that first pic that for some reason didn't work in the above post.

Wow.....

11 x 10 for the prop. Glad you got it off. Put a bunch of anti sieze on the shaft before the new prop.There should be room for a jam nut as well it will give you something to hold on to next time. Mines the same way i change the prop once or twice a year due to sand. What size boat ya running? That will help with prop choice.