# 411 Discbine Rebuild



## lfc (Jun 23, 2010)

I have an early 411 that I bought new in '88. It has probably cut 3000 or so acres in its life, but those were all small, rocky New England fields! I've run it 99% of the time, and it is in very good appearance (other than needing new skirts.) A few years ago I picked up a piece of support wire that the power company had left in the field and gouged the rollers, so they were replaced by the power company. Good timing, as they were starting to peel. Overall, it has been a great machine and I would never want to go back to a Haybine.

I'm careful to change the cutterbar oil once a year, and noticed at this last change there were a lot more metal flakes on the magnetic oil plugs than usual and even a metallic sheen on the drain pan after dumping out the oil. I checked the plugs again after another 10 hours of use, and there is still a lot of metal flake present. I assume a bearing is starting to go. It has always been noisy, but I haven't noticed any other issues.

So, how far should I go with a rebuild of the cutterbar? Take it apart and only fix the bad bearing, or replace them all? New spindle bearings look to be about $1k, but the idler gear/bearing assemblies are another $1600. There is about 1" of backlash (at the knife tip) in the entire cutter bar - is this good or bad?

Is there anything else I should consider checking? I've heard that the flexible cutterbar drive coupling can let go. Do the other gearboxes ever cause problems?

Even if I end up replacing all bearings and also replace the skid shoes, rock guards, lifters, etc I'll have around $4k in it. A lot to spend on an old machine, but better than spending a lot more for a new one, I think. Thanks for any advice.


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## Josh in WNY (Sep 7, 2010)

If it is a bearing wearing out, they are all probably getting pretty close to needing replacement, so I don't think that just fixing the one is the way to go unless you really want to keep pulling this thing apart all the time. 1" of backlash seem like quite a bit to me, so it's definately time to do something in the cutterbar, even if it is just to adjust some shims to get the gear mesh readjusted.

I would say $4,000 is quite a bit to spend on an old machine, but you are right that newer ones cost quite a bit of money. However, if you can find a decent used machine, that $4,000 will go a long way towards a down payment. Given the time of year, you have a lot of time to look around and see if you can find a deal on a used one that is in good shape. If you don't find anything by late winter, order the parts you need and rebuild the one you have before the next season.


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## lfc (Jun 23, 2010)

Josh,
The 1" backlash is over all 16 gears and there is no way to change it other than replacing the gears. If I replace the idler gears and bearings, that takes care of 10 of the 16.

I'd rather fix mine than buy a used one - too much risk I feel in any used machine. Around here, it seems that the only used models available are hardly one step up from parts machines.


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## Josh in WNY (Sep 7, 2010)

I forgot that the 411 has the gears laid flat across the width of the cutterbar. I have a CaseIH 3309 and it uses the hex shaft to drive independent gearboxes. You can adjust the backlash on mine by adding or removing shims in the gearbox. Replacing the idler gears on your mower will remove some of the backlash, but probably not all of it. As long as the turtles are not hitting each other and the gears are not completely loosing mesh, I think it should be ok.

As for used machines, I completely understand what you are talking about. I kept looking at what was out there for years before I finally found the 3309 that we run now. There were a couple of reasons I felt comfortable buying it. First, we knew who had owned it previously and knew how they had run it and maintained it. Second, the dealer gave us a warranty on the major components (gearboxes, driveline, frame, etc.).


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## lfc (Jun 23, 2010)

Josh,
I agree - if I knew the history a used 1411 would be worth it, but they are hard to find. It amazes me what people can do to their Discbines. There were several 411's in my area when they first came out - one filled the cutterbar all the way with oil and blew the seals out, and another fell asleep and mowed over a stone wall. Hate to think that they ended up as trade-ins on a dealer's lot!


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## mike10 (May 29, 2011)

If you go into the bar, replace all the idlers. There is another possible source for the metal. Most of the cutterbar failures I see on these machines, aside from impact damage, is caused by the bearings on the drive end of the cutterbar. The first disc is mounted to a shaft that has two bearings on it and in a housing bolted to the top of the cutterbar. When these bearings go out metal is circulated throughout the cutterbar. When they are bad enough you can move the cutterbar on that end. Place a jack under the front of the cutterbar on that end and raise the bar. If you have any movement of the bar the bearings are going or have gone out.

Once there is metal in the bar you are taking a chance the idler bearings will fail, which is what happens when the end bearings go out. If you don't repair it you can expect a catastrophic failure of your bar.


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## lfc (Jun 23, 2010)

Mike,
I really appreciate your advice on replacing the idlers. I have a service manual, and it looks like the two bearings in the drive end support tube though are not lubed with the cutterbar oil? There are two other bearings in that end spindle, and one of those is below the seal. Is this the bearing that typically goes bad? It looks like all of the bearings are easy to change once you get it apart, so while I'm in there I'll change all of the bearings I guess (five on the drive end, three on the far end) plus all ten idlers and the other four spindle bearings - 22 total! Is there anything to check in the bevel gearbox, or just reset the backlash? Do you agree to change the flex coupler while it is apart? Think I'll sandblast and paint the whole machine too while I'm at it and have it that far apart.


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## mike10 (May 29, 2011)

You are correct about the bearings I was referring to.

When I drop the cutterbar I unbolt the drive end support tube from the bottom of the gearbox. This leaves the gearbox and the conditioner gearbox in place when the bar is lowered. Even if you remove the gearbox there is probably no need to do anything with it. If the lower seal has been leaking you can replace it without removing the gearbox from the machine.

As for the coupler, you will be able to see if it is damaged. Check the splines on the shaft and the hub below the coupler for wear. I also like to replace the large bolts at the bottom of the end gears and I also think there is a third bolt at the top of the right end shaft. I also replace the 10 bolts that hold the idler gear bearing supports, hex socket head bolts. Be sure you install the washers under the bolts the correct way. All these bolts have a patch of locking compound on them so they don't work loose. You will also need 48 orings which go on the spacers in the cutter bar where the disc hubs mount and of course the 6 orings for the disc hubs. There are also 20 orings for the idler supports. Two new gaskets for the ends of the cutterbar and I also like to replace the nuts that bolt the 4 center disc hubs to the cutterbar gears, 16 of those. When you remove the two end disc hubs from the bar you will probably see that the four bolt heads, on each end, are worn and probably should be replaced. I also replace the four large nuts on the center four spindles. Check the splines on these four shafts for twisting. Be sure you install the large washers under the large nuts the correct way.

It might be overkill to replace all the hardware I have mentioned, but if anything comes loose you can kiss the bar goodbye. Use a torqure wrench to tighten all the hardware. If you follow the service manual you should not have any problem. Be sure you use the correct torque for the size of the large bolts on each end. There were two different diameter bolts used depending on the year it was made and the service manual can be a little confusing on the end discs.


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## lfc (Jun 23, 2010)

Again Mike, I can't thank you enough for the advice. I follow everything that you are suggesting to replace. I read somewhere that those bolts from the bottom that hold on the end hubs can really rust in place. I've got plenty of time at least, but my next step is to sit down with the parts list and start writing down numbers - and prices.


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