# Vermeer 7030



## hermit (Jun 4, 2016)

I have a Vermeer 7030 disc mower that has started giving me problems and I was hoping for some help. Last year a bearing went out and locked up the gearbox and somehow the 14mm hex drive shaft for the cutters heads broke. Over the winter we rebuilt it, replacing all the bearings in the gearbox. It feels very smooth now, but it has already broken 2 of the hex shafts this year. Both are broken just outside the gearbox. When turning the cutter heads after the shaft breaks, they turn freely and are smooth with no obvious tight spots that would suggest twine or anything wrapping around the pods.

After taking the bar apart (removing all the cutter heads in the process) I can't find any reason for the shaft to break. I asked the operator if what speed he was going and today he told me the hay was very thick so he was in low range, 2nd gear, which means a ground speed of about 2 mph, because I had told him after breaking the first shaft the only reason this shaft should break was either very high torque or hitting something with the cutter. He also told me he was at the end of the row, turning to start cutting the next strip and not even cutting at the time.

When we rebuilt the gearbox, we went through each cutter unit to check the bearings and replaced all we found bad. As I mentioned earlier, I turned the end cutter and all the cutters turned easily and smoothly, which suggests to me there is no problem in the bar.

I can't find any information that is not several years old on the mower. Does anybody have any newer information regarding these mowers? I am wondering if this could be a design flaw because of where it breaks, just outside the gearbox. This is the location that would take all the stress for the entire cutter bar.

Any ideas would be appreciated as these shafts are a couple hundred each.


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## mike10 (May 29, 2011)

I do not know how the Vemeer is setup, but when a shaft breaks as you describe, I would look for a misalignment problem. If there are dowel pins and dowel pin holes between the mating surfaces you need to make sure they are not worn.


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## Tx Jim (Jun 30, 2014)

I'll be monitoring this thread as my Vermeer M7030 disc cutter just had that hex shaft that OP refers to break and I'm in the process of replacing that expensive little 4 ft hex shaft($258). Old shaft appeared to have be partially broken indicated by rust in part of break. 2 yrs back my disc cutter encountered a gate hidden in the tall grass that damaged the RH end cutter head which I was thinking cracked failed hex shaft at that time. To add to the hex shaft stress I cut a Coastal field that had many bunches of Love grass that caused the drive belts to jump off sheaves. Shall I mention I hate Love grass!!!!!!!!! My cutter bar heads rotate easily with no undue noise. I guess I'll find out after it's repaired and the ground dries enough to cut grass.I think with the "large tie bolt" that holds cutter bar segments together it would be difficult to assemble cutter bar incorrectly but I've been wrong before..


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## hermit (Jun 4, 2016)

Tx Jim, when putting it back together, watch out not to turn the spacers upside down and keep the cutters in order. My son put a couple of the spacers upside down but I caught it before we put the end bolt on. I don't believe the skids would fit correctly when they were upside down.

Other than keeping all parts in the correct order and orientation and making sure the timing is correct, the bar is very simple. I bought a service manual and it advises to coat the hex shaft in a heavy grease, which was a little difficult to find locally but it was available on ebay.

The nut on the end torques to about 700 ft lbs, which I used a 3/4 socket and cheater totaling about 3 feet long that I put about all my weight on to get. Not exact, but I figure close enough.

I will be watching as well, hoping you had better results than I did.


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## Tx Jim (Jun 30, 2014)

I was thinking torque on big nut is 740 ft lbs but I'll have to check tech manual that local dealer gave me. Thanks for heads up on the grease although I fail to see the need for the grease. I don't know what you weigh but I think when my mechanic(170#s) tightened nut he utilized a 6 ft long cheater pipe


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## E220 (Feb 10, 2016)

When a shaft breaks just outside the gearbox, it is nearly always insufficient torque on the big nut. The cutterbar relies on the flat surfaces of the gearboxes to hold it straight. If there is any movement at all it allows it to flex and the shaft is hard enough that it snaps easily. When you lift it to turn, the torque is all concentrated on the base and the flex will snap shafts like toothpicks.

(Trade secret redacted. PM for info)

Also clean all the flat surfaces as you assemble it. Make sure you have the washer behind the nut. That washer is hardened and will allow the nut to turn without galling fast to the end plate. Then take the nut to at least 800 ft lbs. I prefer too high rather than too low. That will be about 19 ft lbs on a torque multiplier. Make sure the bar is straight as you tighten it. Generally we want about 3-5 threads though the nut.


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## hermit (Jun 4, 2016)

As you can tell by the dates of the posts it has been a long time. After a couple health issues I got the mower back together and used it last summer. E220 and Tx Jim were spot on when discussing the torque on nut at the end of the cutter bar. Thanks for the info and the advice, it really helped. We mowed about 50 acres and thought the thing was fixed, but the shaft spun in one of the cutter pods at the end of the summer. It took us until now to get around to tearing it apart again, and we found one of the shafts had stated to twist. One end of the shaft was flat but the other end was on the point of the shaft, so being a hex shaft I would think that means it twisted about 30 degrees.

Problem I am having is locating a shaft. Apparently Vermeer has a really hard shaft and they cost over $200 each last time I checked. Does anybody know of a source where they may be less expensive?

Thanks for any help.


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## Tx Jim (Jun 30, 2014)

Sorry I can't answer your question. I sold my Vermeer 7030 after I bought/cut with a Krone 283


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## hermit (Jun 4, 2016)

Tx Jim, I don't blame you. It is a very simple mower, but it is particular. I just got the prices for the shafts from my local dealer. Together they will cost over $500. You wouldn't know of a junk yard....uh, used parts dealer, that may have a mower like this would you?

Thanks again for the help you gave me on this thing.


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