Mower spindles

[whateg01]

I know there have been many discussions about mower spindles in the past. I've not seen any with the problems our local makerspace has with their Craftsman. It uses the spindles with the 5-lobed blade end and a pseudo-splined end for the pulley. I suspect that they haven't been getting things installed right, but when asked to have a look at it this week, I was expecting the apparently more common dry or contaminated bearings. Instead, I found that the lobes on the bottom of the spindle were rounded off on two of them and the splines on the shaft were worn away where the pulley sits at the top of one. I also noticed a box of old pulleys that had the stamped splines worn away as well. In fact, one had apparently been run that way for awhile as the hole in the middle was over an inch in diameter. I hope to find out what they are doing wrong when installing the replacement spindles and blades, assuming they just aren't getting them tight enough. But is that really the case? Or is this, like the sealed bearings with a grease zerk, just a crappy design? Are there better spindles that can be adapted to fit this style of deck?

This is one of the spindles that was removed.

These are the style of spindle that is used.

 

[matt_i]

I know of only one spindle and that's a Woods. Tapered roller bearings, taperlock sheaves, built for a long haul: ye keep it greased, ye shall keep mowing unabated

I also go by the "rule of thumb"....a branch smaller than my thumb I will mow over, a branch larger than my thumb I'll stop and remove it.

 

[spudley]

Spindles on my old faithful Simplicity used to scare me as they weren't cheap to replace. Then one day I took one apart and found two $4 bearings doing all the work.

Now I can look spindles straight in the eye without blinking.

 

[finn]

Probably run with a loose spindle nut, which allows the blade to wobble and wear the splines.

 

[Captain Spaulding]

Maybe a spacer/washer left off.

 

[mitusa]

Probably run with a loose spindle nut, which allows the blade to wobble and wear the splines.

This^^^ . Are those nylon lock nuts? And is there room for a large flat washer? I would think a washer would help lessen the chance of it getting loose......

HTHs

 

[mvortex1]

I run OEM on my more expensive mowers because I'm super careful what I mow over. My craftsman "field mower" has had the deck gone over probably 4 times in the past 3 years. I ruin belts, shatter spindles with that thing. I'm into it for about $300 total for the entire tractor but am thinking this year of just getting a 3PT field mower. Point is, if you use your stuff hard and don't mind working on your stuff go with aftermarket.

 

[TractorJeff]

Just an opinion;
I would go buy blades at TSC for my zero dollar Craftsman.
I blew up a spindle last year, went over to the mower Shop, He zipped one off a low hour Deck for me. Looking at the Blades, he said I should take them also as they were Sears OEM blades. They were twice as thick as the TSC blades.

 

[whateg01]

Just an opinion;
I would go buy blades at TSC for my zero dollar Craftsman.
I blew up a spindle last year, went over to the mower Shop, He zipped one off a low hour Deck for me. Looking at the Blades, he said I should take them also as they were Sears OEM blades. They were twice as thick as the TSC blades.

If the blade they are using is much thinner, it certainly could keep the bolt from cinching it down. I'll have a look at that when I go look at it later today.

 

[whateg01]

This^^^ . Are those nylon lock nuts? And is there room for a large flat washer? I would think a washer would help lessen the chance of it getting loose......

HTHs

The bottom uses a bolt but I don't know if it's flanged or uses a washer or anything. The top uses a lock nut, the style where the first thread is deformed to create the interference.

 

[whateg01]

Spindles on my old faithful Simplicity used to scare me as they weren't cheap to replace. Then one day I took one apart and found two $4 bearings doing all the work.

Now I can look spindles straight in the eye without blinking.

I had hoped that was what I would find with these. They use 6203 and 6204 bearings so if it was just bearing failure, it would be super cheap to replace them.

 

[Innovate1]

I have replaced a few spindles like that. If the blade isn't aligned with the teeth when it is installed the blade will chew up the teeth which is exactly what has happened. It's a little hard to do it with the deck on the machine. You have to tighten the bolt (not really tighten but just thread in. I can do this by hand with my fingers) just to the point where the blade is starting to contact the teeth. Then turn the blade to engage the teeth. then turn the bolt some more, again by hand, to raise the blade onto the teeth. If the bolts are rough you may need to use a wrench to get to this point but it shouldn't take much force. When the bold is snug against the blade you should be able to push and pull on the blade tip and feel almost no play in the mounting. Then, when the blade is seated on the teeth and the blade is almost tight you can torque the bolt tight. If the tooth damage is minor (yours isn't!) you may be able to clean up the rough spots so a blade will go on and fit tight - I had to do this once when not getting it on right.

The bearings in the spindles are standard sizes and are pressed on. They can be replaced with an arbor press. When pressing on the new bearings press on the inner race with some tubing so you don't put the press force on the balls - that can substantially lower the life of the bearing.

The unit you pictured is shot. No way you will keep a blade from spinning on those.

You can buy replacement spindles for reasonable cost. Jack's small engines is an on line site I use but there are others. Had to replace one when a kid mowed over a cobblestone and busted the whole spindle frame from the mower deck. Luckily the deck was fine and a new spindle fixed it.

The top pulley has a finer spline although I hesitate to call it that - the depth is shallow and the sides are tapered making it weak. Once things start to move back and forth it can strip out in short order. But with tight connections they should last ok. I replaced the top pulley when I replaced the shaft assembly because it was all worn and deformed. It might have run for a short time but best to replace both and not have to deal with it again for a long time.

Sounds like someone may be mowing rocks or treating it roughly or it's just really old and had a hard life. These mowers are not farm tractors and meant for fairly smooth ground and finished lawns. They will handle a little more but a rough operator can break just about anything.

You need to replace the spindles with the new ones you pictured and the pulleys on top. That should go a long way to having a good mower if you can keep others from tearing it up.

The bearings are sealed. You can pump the thing full of grease and I have seen some with grease fittings but I don't see the point. It's going to have a hard time getting past the seal into the bearing. The bearings come with grease and by the time they give out a bearing replacement isn't a big deal. A little observation (is it starting to wobble or make more noise) and some preventive maintenance (fixing it before it fails completely) goes a long way.

 

[BillK]

I would like to see one of the new spindles. The old one you show in your picture almost looks like the blade would need to have a little "step" on it to fit all the way down on the splines ? Like the others have said, maybe they are not tightening the nut properly or the blades are the wrong thickness ? Given the number of problems they have had I would want to find a torque spec and torque the nuts. Then maybe run it for an hour and retorque ?
Also, just like everything else now days I imagine there are good spindles and they are bad ones. Same with the blades. Make sure the new ones fit the spline properly ? Thats all I can think of.

 

[whateg01]

They have been replacing a couple of spindles every year on this thing. That was what prompted me to look into them just being a bad design prone to failure. But like I said, the "normal failure" is the bearings and these aren't that. Hard to believe they keep installing them and the blades improperly, but not getting them tight enough I could see.

 

[Innovate1]

I would like to see one of the new spindles. The old one you show in your picture almost looks like the blade would need to have a little "step" on it to fit all the way down on the splines ? Like the others have said, maybe they are not tightening the nut properly or the blades are the wrong thickness ? Given the number of problems they have had I would want to find a torque spec and torque the nuts. Then maybe run it for an hour and retorque ?
Also, just like everything else now days I imagine there are good spindles and they are bad ones. Same with the blades. Make sure the new ones fit the spline properly ? Thats all I can think of.

The blades are just flat plate with a star shaped hole - no special step. Standard stuff on Husqvarna, Craftsman, AYP, and maybe others. There are certainly variations of quality from different suppliers but that part was rode hard and put away wet. I bought Stens brand for replacements. You can get the whole housing and assembly (less the top pulley) for about the same as the center shaft and bearings.

This link has pics that show the blade end. Not a good price but the pics are good.

https://www.amazon.com/8TEN-Craftsman-Husqvarna-532192870-532187292/dp/B07D9YRMC2/

 

[Innovate1]

I mow a couple acres with a mower deck like that. It's way over the size lot they recommend for that mower but it lasts for years between issues. The ground is a little rough but no rocks. No way you should be replacing a couple spindles a year. How often do they have to replace the blades? Does the engine run smoothly? Hard to tell from a distance but I would be looking at other things too. Does the belt jump off the pulleys and jamb things to a sudden stop? Whatever the issue is it isn't just the spindle design.

BTW, that spindle looks older than 6 months. Just saying. I suppose it might be that new.

 

[whateg01]

...You can get the whole housing and assembly (less the top pulley) for about the same as the center shaft and bearings.
...

That part *****. The whole assembly is about the same cost as a shaft alone, and even with new pulleys a pair costs only a couple bucks more than a couple shafts. I was hoping it was bearings because that would have been a cheap thing to fix, a couple bucks each. As it is, though, I will recommend they just buy more assemblies to keep on the shelf, but hopefully, I can address whatever they are doing wrong at installation that is leading to these premature failures. Else, I may look at putting a better designed spindle in, like one of the Scag parts. Problem with that is, they can still fail if not maintained or if abused. It's just a more expensive problem then.

 

[Innovate1]

Curious which maker space. I went to the Maker fair in KC a couple years ago and toured one of the maker spaces. Very cool!

Was just noticing the link I posted brand is 8Ten. Looks like they are trying to make the name look similar to Sten, which is a decent brand IMHO. I would stay away from 8ten. They should be about half of the 8Ten link for Sten parts.

Edit: Just realized the listing was for two. Doh! So you can get real Sten for about the same price. Have no idea about 8Ten quality.

 

[Innovate1]

Not sure this is exactly the part you need but it is close. $28 for the shaft/housing assembly.

https://www.jackssmallengines.com/jacks-parts-lookup/part/universal/285585

 

[whateg01]

That looks like it. eBay has them $36/pr. I'm looking at the dimensions for the spindle for a John deere l110. It looks like the one on my montgomery wards mower. Seems like it would be a lot harder to screw up.

This is the makerspace in Wichita, MakeICT.

 

[Firebrick43]

I know of only one spindle and that's a Woods. Tapered roller bearings, taperlock sheaves, built for a long haul: ye keep it greased, ye shall keep mowing unabated

I also go by the "rule of thumb"....a branch smaller than my thumb I will mow over, a branch larger than my thumb I'll stop and remove it.

You do know that Woods does not make their mowers right? They just have mowers built with their paint and decals. Gravely made their Mid deck ZTRs for years. I know that wood would charge 70 to 100 more mark up on a lot of parts compared to buying from gravely. The older front mounts were made by grasshopper but the current ones I am not sure.

Gravely, scag, and toro have all made models with tapered roller spindles. Yet there are plenty of heavy duty spindles with ball bearings that last extremely long time. It more that they are of sufficiently oversized and in heavy duty housings.

 

[Sumboodie]

I'm not sure what brand Makers Pace is, but I'm familiar with most brands. Have done OPE work for 10+ years.

Either you are trying to mow a "lawn" that should be bush hogged or you aren't tightening the blade and pulley.
Rocks, stumps, branches, high spots, etc will kill the spindles.

We replace plenty each year and it's obvious the customer has been busy hogging when the blades are absolutely hammered to the point they'd cut better if put on backward..

 

[Innovate1]

I'm not sure what brand Makers Pace is, but I'm familiar with most brands. Have done OPE work for 10+ years.

Either you are trying to mow a "lawn" that should be bush hogged or you aren't tightening the blade and pulley.
Rocks, stumps, branches, high spots, etc will kill the spindles.

Yep. That's my guess too. Maybe a combination of both. Would be interesting to see pics of what they are trying to mow but that may not tell the whole story. There may be rocks and other non-mowable stuff hidden by the grass.

Might be enlightening for the OP to hang around while they are mowing sometime but try not to be too obvious about it so he sees what they typically do.

 

[65ranchero]

Once spindle is replaced are they tightening it to their tightness?
Or are they holding the blade to get a firmer grip to tighten it?
Are they using a new self locking nut?
or using a little Locktite?

 

[Innovate1]

There is a spacer that goes between the bearing and the pulley. Don't think it will work without things rubbing without it so I doubt those are left out but perhaps. In tightening the pulley nut the blade needs to be installed to get some leverage to tighten it down. Again, not sure how that could be done otherwise but there are probably other ways which may not get it tight.

 

[kelpaso1]

Sheesh, some of you guys are making a mountain of a molehill. First step to changing blades is REMOVE the deck and flip it over. Takes 2 mins at the most. Trying to hold the blade on the deck while still on the mower is a pain and the result is usually failure as shown. Tighten good with an impact, oil any brackets/linkages with oil and reinstall deck.

 

[Sumboodie]

Yep. That's my guess too. Maybe a combination of both. Would be interesting to see pics of what they are trying to mow but that may not tell the whole story. There may be rocks and other non-mowable stuff hidden by the grass.

Might be enlightening for the OP to hang around while they are mowing sometime but try not to be too obvious about it so he sees what they typically do.

I've found a few "ugga duggas" is the best way to get them tight.
Now don't get stupid and put the 700ft lbs gun on it like it owes you lunch money, just a couple blasts and it'll be plenty tight and not damage anything.

I had a blade get loose at home when I got lazy and just tightened it by hand instead of dragging out the impact gun. It chewed up the splines, but those aren't really needed if the blade is tight.

 

[Sumboodie]

Sheesh, some of you guys are making a mountain of a molehill. First step to changing blades is REMOVE the deck and flip it over. Takes 2 mins at the most. Trying to hold the blade on the deck while still on the mower is a pain and the result is usually failure as shown. Tighten good with an impact, oil any brackets/linkages with oil and reinstall deck.

We have a jack that lifts the tractor or zero turn front wheels.

Some days I serviced 7 or 8 tractors in a row, so had no plans on pulling decks unless I needed to. Some decks are a royal PITA to pull, some are very simple.

 

[kelpaso1]

We have a jack that lifts the tractor or zero turn front wheels.

Some days I serviced 7 or 8 tractors in a row, so had no plans on pulling decks unless I needed to. Some decks are a royal PITA to pull, some are very simple.

Not sure what kind of **** you have to work on but here they are easy unless it is some old antiquated MTD POS. I wouldn't call it servicing if you don't remove the deck, but that's just me. I do it right the first time and never have any come backs.

 

[reader2580]

I'm not sure what brand Makers Pace is, but I'm

Makers Space is the name of the outfit that owns a Craftsman mower.

 

[Innovate1]

Makers Space is the name of the outfit that owns a Craftsman mower.

Sort of. It's a general term for a community workshop. Typically high tech stuff like 3d printers and laser cutters but also may include metal and wood working stuff.

 

[firebirdparts]

It’s definitely a crappy design, and it’s obvious how it has to work. The blades are okay if you look at what you’re doing. The OEM hardware on the bottom is good. The pulleys may not be. I think the quality on the pulleys may have reduced below what is usable. You might have to look for not-the-cheapest. The bad pulleys are usable if you weld the nut to it, but obviously that’s not a solution for civilized people.

 

[whateg01]

Well, I stopped by the makerspace tonight and looked at the mower. Jacked it up and sure enough one blade was looser than, well, inject your own sailor-style reference. And sure enough, even though that spindle was just replaced two weeks ago, it's already pretty buggered. It may be sufficient to last awhile if the blade is tightened properly. As somebody else noted, if the bolt is tight, the keys shouldn't even be needed. The other blade was tight still, but I bet it took less than 25 ft*lbs to loosen the bolt. So, it was just a matter of time before it would have come loose, I'm sure. Now, back to the first blade, the real reason it came loose is probably two-fold. First, it was surely never tight enough to begin with. But second, the washer that was on it was way too wide. I don't know what happened to the original, but this washer isn't cupped to straddle the lobes on the spindle and the only reason it becomes tight at all is that it's wide enough to ride up on the curved edges of the blade. Of course, that's not where it belongs and as it vibrates, the blade flexes, the bolt loosens, etc. So, I'll advise them to get the right hardware and also to invest in a torque wrench. The people that often do the maintenance on things like this aren't really mechanical, but they do take the initiative to do it, so it's hard to berate them. I think if there's a procedure, and it says to torque the bolts to 85 ft*lbs, they'll follow that procedure and all will be well after that. At least I hope so.

Incidentally, I also fixed another issue the mower had. I had noticed when I first looked at it that the front tires were pointed different directions. I got my tape measure out tonight and measured the toe. Sit down for this - 2" of toe out! For some reason one of the tires is completely bald and the other isn't far behind. I then noticed that the caster seemed to be wrong. Pulled the axle and flipped it around and now it's down to a little over 1/2" of toe out. That's due to wear in the steering, but far more acceptable for a mower than what it was. Like I said, the folks there aren't really mechanics, but they try.

 

[Innovate1]

2" is a crazy amount of toe out even for a large tire but for a small mower tire that's insane!

Many blades have some sort of key or pins so I question the statement that if it's tight the keys aren't needed. I suggest you tighten them as best as possible and run it for some time. Then check if they are still tight. Worth checking I think - if it wobbles back and forth the bolts may back out.

 

[finn]

A proper mechanical joint uses clamp load to provide friction to transmit torque to spin the blade. Other mechanical features like keys should only be used for indexing, never torque transmission.

The lobes on the shaft will always fail if the retaining bolts improperly torqued.

In the case of the mower spindle, the lobes are there as an assembly aid only,to keep the blade from spinning while the nut is being torqued.

The homeowner, or whoever is servicing the mower would hold the blade to keep the spindle from spinning while torquing the blade. Friction is what transmits the torque while mowing.

Lacking proper torque (and friction), you end up with a worn spindle.

Basic first year engineering student joint design theory.

For what it’s worth, I have a low end Ariens made by Husquvarna with the same spindle. I hav gone through three or four mowing at my shop, all from striking large rocks, a logging chain, or stray pieces of half buried steel artifacts the previous owner left from his logging operations. It’s really a pretty durable machine considering the low initial cost and the extreme operating conditions I have put it through.

The aftermarket spindles I have been using are inexpensive, but also not as beefy as the original Husquvarna spindles. Some have a grease zerk, which is kind of dumb since the bearings are sealed. Must be a feel good feature.

I’ll probably step up to a flail mower for the Compact tractor this summer, to replace the rider, though. The yard is pretty rough for a regular lawn tractor.

 

[Innovate1]

A proper mechanical joint uses clamp load to provide friction to transmit torque to spin the blade. Other mechanical features like keys should only be used for indexing, never torque transmission.

The lobes on the shaft will always fail if the retaining bolts improperly torqued.

In the case of the mower spindle, the lobes are there as an assembly aid only,to keep the blade from spinning while the nut is being torqued.

The homeowner, or whoever is servicing the mower would hold the blade to keep the spindle from spinning while torquing the blade. Friction is what transmits the torque while mowing.

Lacking proper torque (and friction), you end up with a worn spindle.

Basic first year engineering student joint design theory.

I agree that if the bolt is not tight the lobes are likely to fail. But they do transmit torque. Look at a tractor PTO - splines not friction. Your "rule" about never using keys to transmit torque is ridiculous. Square keys are routinely used to attach pulleys and sprockets to shafts for torque transmission.

Friction has limits and will slip at some point. Since you talk about engineering have you heard of coefficient of friction? Lobes keep it from slipping. If they aren't needed they wouldn't spend the extra time and money to put them in.

 

[Gunfixr]

I have a large hustler commercial zero turn I use on my property. I just had to replace all three spindles, two with bad bearings, the third on it's way. To be honest, the first year, I bushogged hard with it, as I had only recently purchased the property, and it had gone a couple seasons where I had nothing to cut it with.
Anyway, the spindles have grease zerks, which I was greasing, but some research showed they have sealed bearings. Idk why.
The pulley is keyed to the top of the shaft. They were so rusted, I destroyed all three getting them off.
The blade is held by friction. The bottom of the spindle is about 3" diameter flat, with a 5/8" threaded hole in the center. A conical washer, that's as big around as the blade is wide, goes under the head of the bolt, and the service manual says torque to 160 ft/lbs, which I do, with a torque wrench.
The first time I pulled blades, my 300 ft/lb cordless impact almost wouldn't remove them, the washers were pressed flat.
I use their washers and bolts. I have found that, if you hit something solid enough by accident, it'll pop the bolt. It's not bottomed, so the rest will back right out.
Spindles were about $200 each.......
But, i'm done bush hogging, just grass now.

 

[junkyardwarrior]

box store mowers use cheap parts including spindles

all of the box store mowers I've ever worked on had that or real similar style.

I found it much easier to replace the entire spindle assembly than just the bearings, in a lot of cases. Occasionally a customer would request a bearing replacement which typically I'd advise replacement of the spindle shaft pulley, blades, bearings--leaving basically the housing as original, and I did not put any guarantee on them. They're cheaply built/made for a reason.

I sold and worked on Hustler kubota deere exmark grasshopper craftsman yard man mtd murray wizard (briefly) and a few others that I can't recall off the top of my head. I own a kubota, their cheaper version (Kommander Z1xx) and even as cheaply made as it is in comparison to the ZG200 series or ZD series, it's still built 100x better than hustler and in a lot of cases, deere. Grasshopper is overbuilt but overpriced; there are a lot of little things that are just stupid with them. Like the 722D I'm working on as we speak, no lock nuts on any of the drive shaft components. One of the nuts backed off and let the shaft run "cockeyed" which destroyed the other bolt, shaft came off, destroyed the bottom of the radiator, broke (obviously) both flex couplings, lots of busted and bent stuff. All because of not using a lock nut.

 

[Sumboodie]

Not sure what kind of **** you have to work on but here they are easy unless it is some old antiquated MTD POS. I wouldn't call it servicing if you don't remove the deck, but that's just me. I do it right the first time and never have any come backs.

Anything from ~1970s models to near new.

Why should I need to remove the deck? Unless we are putting new spindles or welding cracks, it stays usually stays on.

 

[Sumboodie]

A proper mechanical joint uses clamp load to provide friction to transmit torque to spin the blade. Other mechanical features like keys should only be used for indexing, never torque transmission.

The lobes on the shaft will always fail if the retaining bolts improperly torqued.

In the case of the mower spindle, the lobes are there as an assembly aid only,to keep the blade from spinning while the nut is being torqued.

The homeowner, or whoever is servicing the mower would hold the blade to keep the spindle from spinning while torquing the blade. Friction is what transmits the torque while mowing.

Lacking proper torque (and friction), you end up with a worn spindle.

Basic first year engineering student joint design theory.

For what it’s worth, I have a low end Ariens made by Husquvarna with the same spindle. I hav gone through three or four mowing at my shop, all from striking large rocks, a logging chain, or stray pieces of half buried steel artifacts the previous owner left from his logging operations. It’s really a pretty durable machine considering the low initial cost and the extreme operating conditions I have put it through.

The aftermarket spindles I have been using are inexpensive, but also not as beefy as the original Husquvarna spindles. Some have a grease zerk, which is kind of dumb since the bearings are sealed. Must be a feel good feature.

I’ll probably step up to a flail mower for the Compact tractor this summer, to replace the rider, though. The yard is pretty rough for a regular lawn tractor.

Husqvarna. Spelled just like it's pronounced. Husq-var-na