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Replacing rotor bearings lexion.

30K views 93 replies 17 participants last post by  KMG 
#1 ·
We put both of lexion 590r combines in the shop. Turns out the rotor bearings on both of them are toast...
Now there is a lot of talk about greasing the bearings and stuff. But I couldn't find anything about how to replace the bearings.
Do we have to tie up the rotor in the back, and then undo the front plate where the bearing mount into?
Or take the small shield off with the 16mm bolts heads? And do it tru there?
Is it doable from inside the hopper with the rotors and the impeller in place?
And how can I see if we have the upgraded bearings?
 
#3 ·
I did mine two years ago when I had my impeller and cylinder out of my 590r. It is not a bad job if the impeller is out. You can get the impeller out in several hours. You do not need to tie up the rotor in the back. I greased my rotor bearings often but the grease was not going into the bearing. Now each year I take off the inspection plate with two bolts in the front of the rotor. If there is no metal fragments in there and the grease flows through the bearing when greased you are good to go. I can not tell you if you can do it through the hopper access covers.
 
#5 ·
I replaced the rotor bearings on a 480 a few years back and did it through the access holes in the grain tank. Not the nicest job and not much room to work in but if you have two of them to do the second one should be easier. I put a block between the rotor and concave at the front to hold the rotor in the right place and then i unbolted the grease line and the mounting block for the bearing. I made a little puller to slide the bearing off the end of the rotor. I assume a 590 would be similar. I have a lex 600 but haven't replaced them.
 
#6 · (Edited)
I also made a little puller to pull the bearing out. Once the bearing it out make sure the grease is actually getting to bearing when you pump the grease fittings on the side. My updated end cap had a little spot on the edge of the cap for the grease to squeeze out of the cap after it has gone through the bearing. The problem with mine was the gungeon holes just outside the bearing where the grease passed through to get to the bearing were plugged and the grease bypassed the bearing.
 
#7 · (Edited)
I replaced the rotor bearings (and since greased them more often with a not worn out grease gun fitting) while doing the "rotor flow kit". The flow kit may help but I didn't find it worth the money. If you do the flow kit, you end up replacing the front metal that the bearings are supported by. The kit comes with a little "stand" to support the front of the rotor up. I used it, but a few blocks of wood would shim the rotor up just as well. You should be able to do the process through the grain tank. Having said that, if the rotors need worked on such as new teeth, pull them out the back. If the impeller needs worked on, pull it. Pulling either the rotors or the impeller will make the job nicer, but both can be left in place. If your rotor intake strips (elephant ears) are pretty worn, they should be replaced at this time a well, and can be done from the tank, but it would be much easier to pull the rotors also.

For repairing bearings through the grain tank, I am not very confident how to do so, because I did the flow kit at the same time, and I am unsure what does and doesn't need removed. The bearings hold the rotors from sliding forward. Take a ratchet strap and hook it on a rotor tooth near the back. Run the strap back and around to the other rotor and tighten so they can't slide forward. I think you need to remove the entire front section of sheet metal that supports the bearing, to replace the bearing. The puller I made was used from one of the front bearing plates. This is the item just behind the impeller where the grease comes out. I drilled a hole in the very center of it and threaded the hole with maybe a 1/2" bolt. When ready to pull the bearing, I used this puller and by tightening the center bolt through the new hole, it pulled the bearing forward. You first must remove this cap, and pull out the factory bolt in the middle of the bearing that holds the bearing onto the rotor. When using the puller, the hole behind the middle of the puller cap needs filled with a bolt without a washer so the puller doesn't damage the threads. This newly threaded hole on the "cap" will need a very short bolt re-installed upon final assembly to keep grease in and dirt out.

The first two pics show what it looks like with the impeller pulled. You would still do the majority of the work from within the tank, but would have much more room. The pics shown have the factory, old style bearing holder. The rotor flow kit comes in black instead of grey and doesn't angle upward in the middle of the machine. The third pic shows the original bearing holder removed from doing the flow kit (with impeller installed). It also shows the rotor block to hold the rotor up, as well as the four small elephant ears. These elephant ears are each held on by three allen bolts and nuts. The mounting holes are slotted and it was recommended to me to install the ears forward as far as possible without striking the back of the bearing plate. Too much gap and material could possibly wrap around the front of the rotor. Notice the anti-wrap keystock in the back of this picture on the second bearing holder. This was likely the most difficult part...adjusting the ears without hitting, and then getting them tight with the impeller in my way. It was accomplished, but difficult. The fourth pic shows the "cap" that I used as a puller. I drilled and tapped a hole in the middle of it. With the two factory bolts installed and the tapped hole with bolt in the middle, it will pull the bearing assembly forward, off of the rotor. Don't forget to use the upper two grain tank access holes if needed. Don't cross-thread the two grease fitting lines while re-assembling.
 

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#8 ·
My 570 had one that was harder to force grease into than the other after taking the covers off in the tank I found no grease coming out of the small bleed hole on one side but no damage to the lines , the grease was coming out on the inside of the bearing because the bleed hole was closed off with old hard grease . Is the grease coming out on the inside an indication of a problem or just the only other place it could go ?
 
#9 ·
I am not sure, but I am confident that the longer the small steel grease line, the harder it will grease. These grease banks are nice but the steel lines are too small. The longer they are and colder it is makes it very difficult to really put the grease to it. I changed to NLGI #1 grease before it gets too cold. That really helps get the grease to the bearing.
 
#11 ·
Thanks for the replies!!!
So what I understand is that I have to;
Strap rotors to the back
Support rotors in the front so they don't fall down ones the bearing is off
Undo the front covers 2 16mm bolts
Take out the Center bolt that goes into the rotor shaft
Then undo the grease line and the bolt that hold the front rotor support
Then I can slide the plate with the bearing off the shaft and take it out and put in on the workbench???

Btw, anybody experience with pulling out the rotors from the back?
 
#14 ·
Basically that's how it should work but not in our case. we were able to get the cover center bolt out but bearing was seized on shaft. Was able to remove outer bearing race but inner race was seized on the rotor shaft. after trying every method we could come up with and not removing the impeller, we ended up removing all the plastic shaker pan under the cylinder and put a soaking wet blanket under the concaves and in front of the rotors. Then very carefully we cut the inner race off with a torch. This was much quicker and don't recommend it but it worked. If we would have used the torch right away we could have had this replaced in about 3 hours. We now grease these bearings every day and we make sure to inspect that grease is coming out of the bearing caps before we put machine away for the end of season. this way there is fresh grease in the lines and bearings for storage and we also catch if there will be a problem before we start next year.
 
#15 ·
Ebear one of the bearings will be harder to grease because the little steel line is almost twice as long. When I take off the inspection plates I have someone grease it while I watch the grease coming out. If it come out through the bearing then you are good. When the bearing goes there will be metal parts inside the plate cover in the grease. Another thing I have done is take the grain tank covers off and feel the rotor bearing covers to see if they are cool on the last day of combing.
 
#18 · (Edited)
This is what we did, "we" meaning a Lex tech and me. We were doing the bearing update on my 2008 590. I do not think it would be possible to do the update without pulling the rotors. This involves using a torch to cut off the original front rotor shaft and some grinding and making things fit. Not a bad job on the shop floor but I can't see doing in place would be good.

I looked at the original bearing setup really close. I can not see any reason why it would not work as designed. The grease has to go into the front side of the bearing ( if it is getting there because of problems with the small, long lines) and flush through the bearing and out through the labyrinth seal at the back of the whole assembly. You can't hurt anything by over greasing. The labyrinth seal is just a series of close fitting steel rings, that with excess grease and centrifugal force from spinning while working, keeps the dirt out and grease in. However if at some time the grease was not getting to the bearing and labyrinth seal, dirt could have found its way into the bearing and contaminated the grease in the bearing and possibly lead to plugging the grease access holes. As I said, I can not see why the original system does not work, except that grease is not getting in at some point. Grease the ---- out of them every day! You can't hurt them from too much grease. I think if you only greased at 50 hours as recommend, and only gave them a few shots at that interval, dirt could get in the back end through that labyrinth seal and start the whole problem. I am not impressed with the design. Why wouldn't the owners manual explain that these bearings need a lot of grease? It is a fair question that is asked in this thread, if you can over grease these bearings. How would anyone know that has not had one apart? I have never had a problem with these front bearings on the 480 with 2500 thresher hours or with the trunion and
mounting. We did change bearings only when we rebuilt the rotors and saw no need for for the mod. What do the 700 series do for front rotor support? Seedcleaner, it sounds like your 740 is the same as the 590s?

Just as an afterthought, if these 2 bearings were not greased until totally full, including the labyrinth seal at the back, they would fill with dust in the first hour of combining. How many of these got the 100 ? or 200? shots of grease it would take to fill everything BEFORE hour 1 of use?
 
#19 ·
Ok from what I am gathering here is that the grease coming out on the rotor side is not a problem as it is the only way out with the bleed hole plugged . I was just afraid that there was a seal blown on the inside and without being able to see how it is put together " mine has the updates " I have no way of knowing if this was a indication of a serious problem
 
#23 ·
Ebear I am guessing your trunion holes are plugged with dirt on the one side. When mine was this way it still took grease in the line like normal. From what I recall I think the grease was bypassing or going around the bearing rather than going through the bearing to lubricate it. I still think these bearings are way to small for the job especially as more power keeps being pushed through the same design. I also feel the countershaft size is to small as well and is a weak point of the machine.
 
#28 ·
Asking about pulling rotors because we think one of them is out of balance. Combine vibrates when rotors are going hi speed. If we slow them down the vibration goes away. Probably gonna pull the rotors out of that one to see what's going on.

I checked the rotor bearings a few times in the season, never found steel grindings but did find hard lumpy gummed up grease on the bearing covers. That's why I don't trust the bearings anymore.... So I'm thinking of replacing the bearings even though there is no filings to be found...
 
#29 ·
I have a vibration in my rotors when i speed them up also. I was told it was the plastic wear sheaves on the variable speed pulley on the rotors that are worn and that will cause it to vibrate. Haven't changed mine yet but there is a bit of play in it when you move the pulley up and down.
 
#35 ·
Might be a good idea, if you can get all the metric sizes flanged up with SAE!!

Seedcleaner do you remember if there was a felt seal or some kind of seal at the rear of the original bearing? It would not be too hard to get one made to put in there. Quite a project to install though.
 
#36 ·
thanks transaxial the pictures really help I'm sure now that I have no major problems it was just the hole in the front being plugged that was making it hard to force the grease in but there was definitely grease coming out the rotor side which means it had to go though the bearing
 
#41 ·
I know.... I think I have the updated ones. Because I picked up a new bearing housing (trunnion) last year and that one looks exactly the same then the one I took out of the combine today.
Part# of the one I picked up last year is 7825450. Looked on Claas parts doc and that same part# is used on the new 780's as well.
 
#42 ·
I can't add much to the discussion of how to get your bearings out. I've been told time after time, by many people that you cannot over grease these bearings. Grease is cheap if you look at the big picture. Milwaukee 18v grease guns are also cheap. We put 150+ pumps in each rotor, every day. I'm not saying I recommend this but we also do it with the separator running to help distribute the grease all around the bearing. The Milwaukee guns have dials to set the number of pumps. I'll set it a 50 pumps and put 50 in one then switch to another, then back, etc, etc. We do it mid day or at the end of the day so everything is warm and greases easier. This ensures the bearings get enough grease and I believe the extra pumps help purge SOME of the old grease and dirt which should help last longer.
 
#43 ·
The last two pics appear to be what I removed and replaced on our 2011 740. One of mine was greasy, the other was dry and smelly like the one pictured. I didn't study it too long, but I didn't fully understand how the grease was supposed to travel from the grease line, and eventually come out the front cover. It seems to be not built correctly, that it requires so much grease to last. I question if the grease relief hole on the front is allowing dirt in while operating. It also just seems plain complicated compared to a "normal" bearing, and I am of German descent...I guess I am getting a bit watered down.
 
#47 ·
You may be right about dirt getting in the vent hole on the front round plate used for the changeup . I spent some time looking at the original setup and found that the only way dirt can get in is through the back (rotor) end. Seedcleaner do you remember what was on the back end of the bearing for a seal on the original setup? Is it possible that if the bearing does not get filled with grease when the machine is new, that a large amount of dirt gets in instead and ruins the bearing and chances of ever flushing itself clean. All these bearings seem to contaminated with a lot of dirt. Some of you guys that have these apart right now, can you see if it is possible to add another metal seal or another felt seal even to stop the dirt? It would be great to find a simple fix! Maybe some Claas help here would be good since the $3000 update does not seem to be any better than the original.
 
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