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OK, that confirms what I am saying, some of the early 24G tractors had some oddball stuff. Now we know it extended to the deck as well.

That info is for a deck for a ProMaster 400 zero turn, nice to know that is different as well. They are rare.

Clearly later 24G tractors had different spindles and pulleys.

Sheldon
 

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Discussion Starter #43
If any of these can help someone let me know.
 

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Thank you, those are all the "standard" 24G books. Clearly the book for the deck does not reflect what you actually have.

The ProMaster 400 deck is the same basic platform/deck shell as the 24G deck. I was unaware of this issue with different types of spindles.

Like some other GRAVELY stuff, clearly not well documented.

Sheldon
 

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How many threads do you have showing below the nut? This method goes against everything I have ever learned about bearing setups. If that is truely how it works, then all you are relying on is the friction of the nut to hold it in position, and they would probably recommend a new nut each time you changed the blades. The locking feature of the nut does wear out over time and use. The reason I asked about how many threads were showing, if you have a problem with them coming loose, you might be able to buy 3 more nuts and use them to jamb and lock the original nut.

You would think it would at least have been a castle nut with a cotter pin.
 

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Discussion Starter #46
Agreed castle nut and cotter pin would probably be better but gravely didn't think so. My father bought this tractor brand new in 1989. He has sharpen blades and replace blades and replace bearings many times. But unfortunately he is no longer with us and now it is my turn to do what he used to do. He never had any trouble with any of the nuts backing off to my knowledge I do agree with you I am using new nuts and I'm using a better nut that I got from McMaster-Carr. Like I said he never had a problem but when I replace the bearings I thought to myself could this be right and that's when I originally asked the question. I've got a lot of opinions and respect them all.but when I spoke to Richard's is when I realized that they were the ones that truly knew what was going on. He went over piece by piece with me and assured me that what I'm doing is correct. So I have to trust someone so it's him that I will trust. And as I said I will be honest and let everyone know how it turns out should be putting it together tomorrow as I am waiting 4 new glades.
 

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Now getting the whole story on the tractor, ok, like I said above, I think you are right, you need to do what Richard's recommended and see what happens.

I found it most interesting, but not surprising, that your spindles did not match the IPL you have. GRAVELY is known for some documentation issues from time to time.

There are G series upgrades made near the end of production with no known part number for the revised parts.......

My point/question at this point in the discussion is to understand if all 24G 72" decks are like this? I bet not. Because, when I was researching and installing the steering brakes on my 16G, I learn a lot about the 24G.

A poster who is not active on here any more had a fleet of 24G tractors and could tell you all the small differences. He made many comments about how the earliest ones were different and poorly documented compared to the later ones.

One note about bearing design theory - as an automotive front wheel bearing, these bearings are loaded from the out side in, meaning the torque comes from the spinning hub. There is little force that would spin the inner race on its shaft. The tapper and the vehicle weight load the inner race against the spindle nut/washer, and allows you to "preload" or adjust the free play.

But in these mower spindles, the hub is stationary and the shaft spins. So the first placement of torque is where the inner race meets the shaft. Leading to the idea that this needs to be a secure connection to prevent the shaft from spinning inside the race.

I find it interesting that Richards said these bearings will hold this setting for future blade replacements. I'm not saying they are wrong, I'm trying to understand and learn more here.

Let us know how it goes.

Sheldon
 

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Discussion Starter #48
They did not say they would hold they said that they would have to be readjusted every time the blade is replaced
 

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Ok, I misunderstood, that makes more sense, but again it is interesting that this is not documented in the Operators Manual. Again that suggests that the spindles with the top grease seal washers are different from yours in this respect.

Sheldon
 

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Discussion Starter #50
New blades are coming in mail when they get here I will mow again. These are the new lock nuts that I purchased. Can't hurt. I am going to mark the nut and the shaft after installing then keep a very close eye on them takes me about 4 hours to mow. After finished mowing I am going to take them apart and see if the bearing is spinning on spindle. After all do not want to buy new spindles. If all is well mow again next week and the week after and see how it goes not a whole lot more I can do right now except keep an eye on things.
 

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Interesting to me that your father replaced the bearings many times. These setups are very heavy duty, not like the junk you buy today in the big box stores. He may not have known the design flaw in this setup. I do consider it a design flaw, very un-Gravely like compared to the older models.
 

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Interesting to me that your father replaced the bearings many times. These setups are very heavy duty, not like the junk you buy today in the big box stores. He may not have known the design flaw in this setup. I do consider it a design flaw, very un-Gravely like compared to the older models.
I'm still not convinced all 24G decks are like this. The OP had to match his spindles up to the 72" deck on the Pro Master 400 zero turn, a tractor made about that same time, but not made for very long. As I said earlier, I have been told there were a number of oddball things about the earliest 24G tractors that were changed later.

"very un-Gravely like compared to the older models", also very un-Gravely like compared to my 1995 16G built 6 or 7 years after the 24G in question.

I don't know how many mowing hours the OP has on this deck, or how many times bearings have been replaced, but my 50" deck went some 18 years and 500 hours of sometimes hard use before needing an overhaul.

And actually that is a more complex story.

Some background - my deck, made in 1995 +/-, came with top lube metal seal spindles. In 1999 one of my boys hit a tree stump with a mower blade, crushing the spindle bearings. At the time, I simply bought a complete spindle and replacing the damaged one.

I paid no attention and had no knowledge it was different from the original - it was the top lube/rubber seal version. It is this newer spindle that is showing the serious wear prompting this overhaul.

Upon dis-assembly, it was clear that this spindle had less grease in it and more water/dirt/air/whatever than the other two. For those of you who don't know, the top lube rubber seal spindles have a side relief vent that was supposed to allow them to take the grease properly without blowing out the seals - so much for that idea.

My two original spindles showed only minor wear.

I ended up rebuilding all three to a new design standard. No side vent, rubber seals on the bottom, metal seals on the top, and the newest revised spindle shaft which has better grease ports and longer threaded stems which proved helpful as I was also adding dual blades, you can read about it here:

Latest 16G improvements

That was six years ago, still going strong........

Sheldon
 

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Discussion Starter #53
Thanks for all the input guys but you guys are way too deep into this for me. All I want to do is get back up mowing. I was looking for some advice and boy did I get some. I will be mowing with the tractor again today set up as advised by Richards. There were a lot of design flaws in this world we live in in this case I'm going to just live with it. Again thanks guys.
 

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I had a 72" deck on my GMT 9000, which I think should use the same spindles, et. al. as yours...... the spindles were shouldered, so it simply didn't matter how tight you torqued the nuts on, bearing preload was a fixed property of the spindles/housings....... Made blade changes and such really easy.

I wouldn't be surprised if you could substitute the 'easier' parts for your spindles, and make your blade changes less problematic as well. Something to consider for the future, perhaps.
 

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I had a 72" deck on my GMT 9000, which I think should use the same spindles, et. al. as yours...... the spindles were shouldered, so it simply didn't matter how tight you torqued the nuts on, bearing preload was a fixed property of the spindles/housings....... Made blade changes and such really easy.

I wouldn't be surprised if you could substitute the 'easier' parts for your spindles, and make your blade changes less problematic as well. Something to consider for the future, perhaps.
Actually, a quick check of some part numbers shows no common parts between the GMT900 72" deck spindle and the 24G 72" deck spindle or the ProMaster 400 72" deck spindle.

So there is nothing to suggest that the GMT900 deck spindle would bolt to those other decks or provide correct height or pulley connection and alignment.

Sheldon
 

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Actually, a quick check of some part numbers shows no common parts between the GMT900 72" deck spindle and the 24G 72" deck spindle or the ProMaster 400 72" deck spindle.

So there is nothing to suggest that the GMT900 deck spindle would bolt to those other decks or provide correct height or pulley connection and alignment.

Sheldon
Wow, that's a surprise...... Gravely seemed to really like using the same parts across multiple machines........
 

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Discussion Starter #57
Chill out guys everything's fine just mowed quiet as a mouse no problems nuts didn't move everything is fine.
 

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Chill out guys everything's fine just mowed quiet as a mouse no problems nuts didn't move everything is fine.
Don't worry about us. We just like to debate things. Sometimes the original thread starter and his question gets lost in the shuffle, but sometimes it can be helpful also. I am glad it's working for you. If the nut stays in the right place, I see it giving you years of service now that you know the score. If it were my mower, I would have put the nuts on with a air impact and and would have tried to run it like that, scratching my head till I figured out what happened.
 

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Sheldon's method of rebuilding these style spindles is spot on. The top and bottom spindle nuts MUST be tightened down completely tight with no pre-load set in order to safely run these spindles. Every item on the spindle shaft is a slip fit and the parts on the shaft rely on those nuts being tight to operate properly. If the nuts aren’t tight than the bearings, seal, blade cradle, and pulley are free to move around on the shaft. Over time this causes severe wear on those items, and eventually the spindle will destroy itself while in use. I’ve seen it time and time again while rebuilding these spindles when a PO has not reassembled them correctly. Upon reassembly if you find the bearings bind than you need to place a .005 shim between the bearing and the machined spacer on the shaft. Use however many are necessary in order to achieve proper free play with the nuts locked down tight. I use shims 3088A236 from McMaster-Carr and cut the OD down with a pair of heavy shears.

I’m not sure why Richard’s would’ve said to back the nuts off the spindles partially, and that having to adjust bearing load at each blade change was normal. That is definitely not the case. The spindle nuts needing to be locked down tight is a prime example of how important this step is when rebuilding these spindles. If the nuts are locked down tight from the beginning than bearing load will always stay the same any time you change a blade, no matter how tight you get the nuts after reinstalling the blade.

If these spindles were a press fit assembly, such as on the Commercial 40” deck, than you would leave the top nut loose to adjust for bearing load. This is because the bearings are an interference fit on the shaft and they’re unable to move around on their own. There is also not a spacer between the sets of bearings to set bearing load, so it has to be done with the top nut. The bottom bearing backs up to a spacer machine to the shaft, so bearing load will stay the same any time you change a blade.

I would highly suggest you remove your spindles and rebuild them properly. Otherwise I guarantee you will be calling Richards again to buy more than just bearings the next you have to work on them.

Rick
 
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