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How often do you add grease to the fitting on the deck on a DGT6000? Guy at sears said three pumps per year each. I think he is smoking something.
 

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The spindles on my 50" deck don't even have any zerk fittings. Or atleast I haven't found any. My manual doesn't say anything about it. What size deck did you say you had?
 

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It really depends on the amount of use and how you clean your machine. I put a lot of hours on my GS6500 and power wash after every mowing so I grease evry time. I only shoot it with one pump on each mandrel and 4 yrs and over 250 hrs the mandrels are still free.
 

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The guy at Sears is either a fool or an idiot who has never used the equipment.

I also have a DGT6000 with a 54-inch deck.

Being an old farm boy, the rule I learned was to grease until it came out or at least several pumps every time it was used.

I've been using this technique until this summer when I had to take the mandrels apart to clean them. I discovered all the grease I had been pumping in was stuck to the middle of the mandrel shafts or spattered against the walls of the cavities in woefully inadequate amounts.

The grease holes come out of the shaft about and inch below the upper bearings, which are sealed on both sides so the grease can't get to them anyway. The grease also wasn't getting to the bottom bearings. They're open on the top and shielded and sealed on the bottom so the grease would help them if it could get to them. They were sitting there naked and barren with the closest grease a couple of inches away and appearing to have no desire to go down on the bottom bearings and service them. Basically, just giving them a few squirts was useless.

I greased the bottom bearings and after I reassembled the mandrels I emptied my grease gun into them with about 30 squirts apiece, to no satisfaction. The shafts still spun freely with apparently no grease getting to the bottom bearings other than what I had put there. I picked up some more grease and after loading my gun, gave each of them another 30 pumps but again to no satisfaction. I left them at that point hoping I had put enough grease into them to at least put smiles on their faces. At this point I think it would be better to fill a grease gun with gear lube so at least the lubricant would get down to the bottom bearings.

I believe each mandrel can probably hold about a third to a half a tube of grease, but should be satisfied with a smaller amount that will ooze down onto the bottom bearing. The important thing other than getting the grease into the bottom bearing would be to make sure the bearings seals are in good enough shape to prevent water penetration that would destroy the bearings. Depending on the age of the deck and whether any water has gotten in it might be worth the time to disassemble them to make sure they not corroded.

Runningbare
 

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Discussion Starter #5
Guys thanks for the replies. I knew the guy at sears was nuts. I usually pump about twenty pumps every other use. Seems OK so far. I think I have had it three years now with no trouble except a broke flywheel key.
 

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Madmantrapper,

In my post above I mentioned that it might be better to just pump in gear lube instead of trying to pump in enough grease to lube the bottom bearing because it would take so much grease to fill the mandrel.

I have thought more about it and how to do it, when it dawned on me that all I had to do was remove the grease zerk, stick the oil gun tip into the hole and pump. It would push out the remaining grease in the fitting and run down to the bearing. It shouldn't take more than an ounce or two to do the job.

It would be a lot more effective and economical to use gear lube because it would make it all the way down to the bearing and not just sit there like grease does while the bearing failed. Next time I'm going to try it.

Runningbare
 

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Madmantrapper,

In my post above I mentioned that it might be better to just pump in gear lube instead of trying to pump in enough grease to lube the bottom bearing because it would take so much grease to fill the mandrel.

I have thought more about it and how to do it, when it dawned on me that all I had to do was remove the grease zerk, stick the oil gun tip into the hole and pump. It would push out the remaining grease in the fitting and run down to the bearing. It shouldn't take more than an ounce or two to do the job.

It would be a lot more effective and economical to use gear lube because it would make it all the way down to the bearing and not just sit there like grease does while the bearing failed. Next time I'm going to try it.

Runningbare
I suspect the problem with gear lube would be not a good enough seal to hold it in and it would just run out bottom.
 

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MowerGraveyard,

You're correct to a degree, but the bottom bearing is sealed on the bottom side. There might be some seapage over time, or when the seal finally wore out, BUT, by usng gear lube, the bearing and seal would get lubrication that it's now not getting.

RB
 

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I used a mix of 90W and grease in a 4x4 truck I had,its front axle u-joints were "enclosed" on that truck in a large ball and socket arrangement,that had felt seals and leaked like a seive..

it was supposed to have 90W oil,but it would leak out in a few weeks,and made a mess of the driveway and parking lots--so rather than tear the whole front end apart,I tried pumping in some grease with a grease gun,about half a tube,after a friend said that was an old used cars salesman's trick, to seal them up--after a few weeks once the grease migrated outward to the leaky areas,it barely leaked a drop--the u-joints didn't ever wear out being "drowned" in 90W and grease either,guess the thicker grease didn't harm them any..I wish my current 4x4 didn't have "open" U-joints,they rust to death and fail in 2 years time..:( I dont see why 90W and grease wont work on mower spindles..
 

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Discussion Starter #11
I used a mix of 90W and grease in a 4x4 truck I had,its front axle u-joints were "enclosed" on that truck in a large ball and socket arrangement,that had felt seals and leaked like a seive..

it was supposed to have 90W oil,but it would leak out in a few weeks,and made a mess of the driveway and parking lots--so rather than tear the whole front end apart,I tried pumping in some grease with a grease gun,about half a tube,after a friend said that was an old used cars salesman's trick, to seal them up--after a few weeks once the grease migrated outward to the leaky areas,it barely leaked a drop--the u-joints didn't ever wear out being "drowned" in 90W and grease either,guess the thicker grease didn't harm them any..I wish my current 4x4 didn't have "open" U-joints,they rust to death and fail in 2 years time..:( I dont see why 90W and grease wont work on mower spindles..
Man that reminds me of some good memories of a 1975 ford F250 I had with a 3300 lb front axile with those miserable felt seals. I did the same as you with the grease. The felt lasted a couple years that way. Without the grease the felt wore out in months.
 

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MowerGraveyard,

You're correct to a degree, but the bottom bearing is sealed on the bottom side. There might be some seapage over time, or when the seal finally wore out, BUT, by usng gear lube, the bearing and seal would get lubrication that it's now not getting.

RB
I think I will try this. I have 200 hours on it now and don't want to have to rebuild mandrels any time soon.
 

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I am confused... I just pulled the center mandrel from my 54 inch deck and it was loaded with grease to to bottom. Also if you are running it for a period of time the grease will flow to the bottom as it heats up....maybe and thats a just maybe you need to use another type of grease.
 

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draddogs,

How much grease have you been putting in? Must be a lot!

When I started greasing, I had thought that the spindles would have been greased at the factory so I put in several pumps everytime I mowed. I was wrong. The only grease was the grease in the sealed bearing at the top, leaving the bottom bearing un-lubricated. The huge cavity for grease takes a lot of grease to fill and after four years of greasing, I had not even started to fill the cavity. The cavity shouldn't take more than an ounce or so of grease, anything more than that is a waste.

The mandrels shouldn't really get hot enough to melt the grease and make it flow down into the bottom bearing. If it does get that hot, the bearings aren't doing their job and are about to fail.

I think Tractor-Holic has the best idea about mixing grease and gear lube to make a thich slurry that doesn't have to get hot to flow, yet be thick enough to not leak out.

Runningbare
 

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Runningbare, when I first got the machine Sears brought it ou to my home in the country. I went over ot with them and since it was delivered by a service man he had a grease gun on his truck. I aske if iwere greased and he said he hadn't done it personally so we shot about a tube into them at the very begining. We pumped the grease gun until I felt it stiffen up and stopped. As I said I power wash every mowing and the grease with a outboard motor grease.

As far as getting hot no they do no get hot as in burning hot but the mandrels will get warm enough after 3-31/2 hours of mowing to make grease flow. Never have I not seen grease flow other than the old fibered wheel bearing grease of old that would not of been able to be put thru a grease gun.

When I pulled the spindle shaft I found the grease clean and uncontaminated by dirt or water. Also to those who don't wipe the zerks clean befor greasing, you will inevitably push dirt into the spindle and rhen you may have a problem sooner than later.
 

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I've got a Scotts (John Deere) 54" mower. When I do mow I run it for about 3-4 hours straight each time, so I put about 3 pumps into each spindle every time.
I don't know how your spindles are, but with mine excess will work it's way out under the deck so essentially you can't over grease it, but you can always under grease anything. When I put new spindles on the deck it took about 3/4 tube of grease to fill all 3 of them up initially.

I don't grease slow moving stuff like the kingpins and steering stuff every time but fast moving stuff like pulleys and spindles get it every time.
 

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From my experience with many hours, since I was 12 years old, in the field running and repairing farm and automotive equipment, I have never experienced a ball or roller bearing that got hot enough for the grease to melt unless the bearing is about to fail. Many times I have seen bearings fail due to lack of grease and soldified grease was only millimeters away. Even in failure they did not get hot enough to melt grease that was close by but only grease that was in physical contact with the bearing.

Lithium based grease, which is most often used for high speed applications like wheel bearings because it is very "sticky" and heat resistent, has a melting (dripping) point between between 350 F and 400 F. This is much hotter than your mower spindles will ever get!

The whole idea here is to get lubricant onto/into bearings to allow them to operate, hopefully the lifetime of the equipment, and keep out contaminants like water and dirt. Anything you can do to facilitate this process is good.

That the Sears delivery person had to push nearly 3/4 tube of grease into the mandrels is a prime example of the manufacturer's lack of concern with greasing the bearings. The bearings are going to last a long time without any additional lubrication -- the grease zerks are just there so the owner can feel good that they're "lubricating" the mandrels. I would rather actually provide lubricant to the bearings than just feel good about it pushing a few squirts of grease into a relatively bottomless pit.

In reality, ball bearings were first introduced in ancient Roman times as a type of bearing that needed no lubricant. In World War II, the German army was said to "...run on roller bearings" because most of their important equipment that required bearings had roller bearings. Hundreds of tons of lubricant was saved because these bearings required little lubricant and could be run dry for extended periods. In the late '60s I ran across and repaired an old German smoke generation machine an older timer had brought back from WWII that consisted of a small one cylinder engine that had a device for dripping oil onto the exhaust pipe to create smoke. After more than 30 years the crankshaft still revolved riding on roller bearings. After cleaning and servicing, it provide many more years of service as a water pump engine until it was washed away in a flood.

Except for extreme conditions, for ball bearings to provide many years of service they just need to be kept clean and cool. The way this is accomplished is to provide a sealant, either a physical boundary such as a shield or seal and/or a medium such as grease or oil that will carry contaminants and heat out of the area. The space shuttle mobile launch pad doesn't use lubricants like we know them. Because of the pressures involved and the subsequent temperatures, the "lubricant" used is a hybrid mixture with an iodine base designed to keep the bearings cool.

Runningbare
 

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I take care of my cars. While my tractor is very clean and looks like new I have 120 hours and never hit it with grease. I am going to do it this week. I can use a full time helper just to keep the oil changed and things greesed. I just hating to take time. Everthing I own is in mint condition. I guess everone needs one thing to neglect. LOL Greese everytime is grese kill. :sidelaugh
 

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You guys have me thinking, again.
I'm in the process of rebuilding my belly mower deck. Took the pulleys off the mandrels to remove them. The blade and mandrel shaft fell out of the mandrels. Both mandrels had a bit of clean grease, but were not packed full. There are no zerk fittings on these mandrels.
The bearings look and feel smooth. No shaft rust.
Should I add the zerks or just load up the mandrel with general purpose grease and close them up?
I broke off a mounting bolt in the mandrel base, too, so I have a little more work to do.
 

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engine2quarters,

You need to check the bearings to see if they are sealed. If you can't see the balls and the rack that holds them, but see a plastic insert or metal shield over the balls, packing the mandrel cavity with grease or adding a zerk will be pointless.

If you can see the balls, just pack them with grease. That much grease should be more than sufficient to keep them going and protected until the next time you rebuild your deck.

If they have seals and you want to grease them, you can get what looks like a hypodermic needle with a zerk on one end to insert into the bearing to lubricate them, or just get a small syringe with an 18 gauge needle available at Tractor Supply or wherever farmer vet supplies are sold. You can go into the sealed bearing by inserting the needle into the bearing between the seal and the center or inner metal (race) of the bearing, it's not connected in that area. It's connected to the bearing on the outer edge.

Runningbare
 
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