New problem with broom - lost hydraulics

oldnslo · Dec 18, 2022

Will having a U-joint and the single bearing potentially allow or cause the opposite end of the shaft to wobble? Reason for question is I believe u-joints change length every time the yokes rotate thru 90 degrees.

mrmikey · Dec 18, 2022

Will having a U-joint and the single bearing potentially allow or cause the opposite end of the shaft to wobble? Reason for question is I believe u-joints change length every time the yokes rotate thru 90 degrees.

As long as you have them timed you'd be ok. By timed I mean the yokes on each end being on the same plane, in other words, if you put a piece of round bar thru the yoke holes on each end they're parrallel.
Just thinking out of the box here so bear with me. If the spline on the pump is screwed up which makes it probably not worth while rebuilding why couldn't you weld the new yoke onto the pump shaft...nothing to lose since the pump would be toast anyway....just a thought

Doaaj50 · Dec 18, 2022

I think that the heat from welding on the pump shaft will destroy the pump shaft seal. If you go with a u-joint then I would look for a clamp style hub.

dstig1 · Dec 18, 2022

I got it apart and had a good look at it. The splines on the coupler are totally sheared off clean. You can see them down farther inside the coupler but they should be out to the end all the way:

I have read all the comments, and thank you for the suggestions and compliments on the work. I made it this way so there would be no loose parts. The pump does slide right into the coupler as I carefully aligned it during final assembly but it is certainly possible to be off a fraction of a degree (actually likely in reality) and that may contribute to it. I am also thinking shock loading may be an issue.

There is not enough room for another Universal joint and I don't think that is the solution. A few of you mentioned a Lovejoy coupling and I had been thinking along those lines too. Unfortunately that leads to loose pieces that I could lose but it is all secured in place at the end so there is no longitudinal movement within the shaft that should cause the spider to fall out, so I think that is the way to go to deal with any slight misalignment and shock loading. Now I need to find one rated high enough that fits. I have 4.5" to the front of the bearing (the blue line), and a ~40-45ish hp PTO rating:

The pump shaft is a bit beaten up but should be fine. And no I won't weld on the pump shaft at all. I have found lovejoys with the same 13 tooth 7/8" spline, so I just need to find a 1.75" dia keyed half for the shaft or modify the shaft end, which may be very tricky to pull off.

A couple mentioned grease and I had put some grease into the coupler but it was just regular bearing grease. I think I will get some of the Moly paste and use that in Version 2.

Here is what the pump shaft looks like.

The only nagging question I have is if something in the hydraulic loop jammed and caused this to shear or if it was just shock loading or the like that lead to it. If there is something in the hydraulics that caused this, the new coupling may last 0.1 sec... I guess I will find out...

mrmikey · Dec 19, 2022

If there is something in the hydraulics that caused this

Unless it's a constant beating/hammering I'm thinking the pressure relief should handle it. What's the relief set at, possibility it's too high?
The pump shaft doesn't look too bad at all.
If the coupling on the pump end is tight i.e. clamped as j50 said that may stop the wear on the pump splines and salvage what is left without finishing it off. You could leave enough space at the spider to make up for expansion. Wouldn't be more than 1/8" I would think.
Pics are great as is the documentation

oldnslo · Dec 19, 2022

Dave
Put a pliers on the pump shaft and see if it turns. Not uncommon they won’t turn by hand but should turn with pliers on the shaft.

When you pulled the pump out was there sheared teeth from the coupling in the pump splines or mostly just shavings? Sheared teeth would points towards shock load failure while shavings would points towards soft material wore out.

I was thinking remove the last carrier bearing and make new shaft with u- joint on each end.

dstig1 · Dec 19, 2022

Pump turns easy with pliers. Should be no issue there. Good call. Not sure on the shavings vs chunks in the splines as much of it fell out when I pulled it.

I found and spec'd a Lovejoy. Dayum they get pricey at this size! Should be out a week or so, and will get ordered tomorrow. The one issue I see for sure is that it is almost certainly going to interfere with the cross brace plate below the front where the coupler sits. So I will need to pull the subframe and hack out that section when it shows up and I know how much to cut away. I don't think it will cause any structural issues as it is quite robust. This way i will be able to fit everything on the bench where it will be a lot easier to work on, too.

oldnslo · Dec 19, 2022

Glad the pump appears undamaged

Hope the storm headed this way at end of week doesn’t dump on you when your broom is out of service.

dstig1 · Dec 24, 2022

My lovejoy showed up today. It is BIG. See pic. I sized it up with the space and you can see how it is about 1/2" too long to fit in between the bearing collar and the front. So I need to shorten it, which I was expecting, shorten the old shaft that it goes onto (sticking through the bearing below it) and cut a matching keyway in that shaft. Plus I need to cut away much of that plate you see down below. Interesting tidbit is the stub of the coupler on the right fits very nicely into the opening for the pump, so I can use that to align it all pretty darn close with the pump shaft. Oh and I need to come up with 7/16" key stock for the keyway.

Doaaj50 · Dec 25, 2022

Wow, that is a big coupling! It‘s a bummer that it doesn’t fit in your original frame. Thanks for keeping us updated as you work through this one. Can’t wait to see more pics of it back in action!

oldnslo · Dec 25, 2022

Can you put the pillow block bearing on the opposite side of the mounting bracket? Can’t tell from pictures if shaft is different size or not.

dstig1 · Dec 26, 2022

The shaft has a universal joint on the other end, then a solid 3/4" x 7/8" shaft that was welded to an adapter and then to the adapter a friend turned for me, and finally to the splined adapter. It was all made to sit at that spot, so the section that fits the bearing does not extend back any farther before it goes to rectangle. I could rebuild/rework the entire shaft farther back to flip the bearing but that seems like waay more effort than is worth it. I need to mill off ~1/2" total combined from both sides of the the coupler. I can take .1 off the face of the splined one and .4 off the keyed shaft one without running too close to the set screws, so that looks like the plan. I am still wondering if I am going to be able to piece it together in the space allotted. That will be the biggest challenge, but I think I can remove shaft sections to get there.

dstig1 · Jan 8, 2023

Finally an update to show. I have a friend who is a machinist that was on vacation and he knows this stuff much better than me, so i waited until he got back and we took a look at it then. Plus just busy with other stuff. Well the conclusion was to cut off the old thing entirely, flip the bearing (as we previously discussed on this thread) and make a new adapter piece. This way it appears we have enough room to get everything assembled properly and no modifying the Lovejoy coupling either.

The plan was to take 1.75" Cold rolled and bore a hole that the rectangular PTO shaft could fit into on one end, and cut a keyway for the lovejoy on the other end. Then insert the rect shaft, which will be centered now, and weld it in place. So the part is now made (pic) but I need to cut the PTO shaft shorter about 1/4" to make everything fit happy. Then I will weld it in place and should be done. I have to grind a little more clearance into the end plate of the subframe, but no biggie.

So pretty close to done now, just need to find time to weld it, wrap it up and reinstall. Hopefully the Lovejoy does the trick!

Here is the PTO shaft inserted in the hole in the adapter. It is a very light press into place. Tapping a block of wood is sufficient to drive it in. You can see the keyway on the far end too.

oldnslo · Jan 8, 2023

Appreciate the update and certainly hope lovejoy solves the problem.

dstig1 · Jan 15, 2023

Finally got it welded today but don't have it all back together. Having a hard time finding the full length Key stock. Need to try another Menards or two to find one that actually has it in stock...

I preheated it to 200+ deg first since it has a lot of mass of cold steel. Just my basic propane/MAPP torch for that. I put down "2 coats"

of hot glue since there was a bit of a gap around the shaft due to the hole size we bored to fit it in. Had the welder turned way up for this one. For those curious:

ER70-S6 0.045" wire
~300-310 ips feed
~25.1 V setting
Prob got 230-240A on the readout, but you have to look quick right after you stop or it disappears and I did not look...

LD1 · Jan 17, 2023

You plan on testing it out before the next snow just to be sure the repair is gonna hold?

dstig1 · Jan 17, 2023

Fer sure. Once I get it all back together there is always a test run...

Only had a little time tonight but I did pick up the correct key stock, so I was able to assemble it. Bolts are only snug right now and need to be tightened down once I am sure it is all aligned correctly, but I kind of need the pump to do that. If I pull the pump off the broom, it is going to be a mess of oil trying to drain out, so I will probably just do the final alignment with it all in place. At least getting under the tractor is super easy compared to most other types of vehicles...

So here it is back together as of now:

The spline has an interesting way to lock the splined shaft to the Lovejoy. You see thsoe goofy looking holes next to the spline there? The holes are basically relief so that the set screws on the outside of the coupling can squeeze down on the spline a bit to give it some friction.

After looking things over with my machinist friend he said that the failure was fretting corrosion, which is something I know was mentioned earlier in this thread here too. So securing the pump shaft to the Lovejoy should help avoid that and the coupling can take up the slop. I hope... Not sure what to do on the off season as the Lovejoy is pretty much trapped but the spline end is not really secured to anything without the pump in place. I don't think it can fall out, but it won't be secured either and can go partway into the 4" bore at the end, which I don't like, so I may have to zip tie it in the summer or something. Dunno yet.

Edit - had a thought while looking at that photo. If I make a steel strap with 2 holes that match up to the pump mount holes, and put a small spacer welded to it in the middle to keep the Lovejoy in place, it should all stay put just fine, and gives me a convenient place to not lose the pump bolts over the summer!

dstig1 · Jan 26, 2023

Back in business! Finally got the PTO subframe remounted yesterday and got the broom back on tonight and tried it out. It all lined up quite easily and I really didn't have to do any adjusting, which surprised me, but I'll take it. Seems to work fine again. After an hour of brooming off the ~1" of powder we got yesterday, I put my hand on the coupler and it was warm to the touch, but not hot. Some of that may be heat transfer from the pump/fluid too. Dunno. So here are a couple shots of the PTO coupling in place and the pump attached, and a short video from the cab of it throwing snow.