Sickle bar mower question

[HarveyCub]

Last year, I came into my first tractor (1966 Cub LoBoy), which had a few extras, including a sickle bar mower. Removed the tow bar and leveling blade and hooked up the sickle bar. As best I can tell by both sight and manual, I hooked up everything correctly.

Out to the tall grasses to field test. Bar lowered, PTO on, mower going. Things seem to be OK for a small while, but boy does this thing seem to shake violently! So much so that some of the bolts loosen from around the PTO (where the mower attaches just below the spindle) and I actually lose some bolts near the connecting rods. Tighten loose bolts, replace lost ones and try again. Same result. And then a third time. By this time, I had to had to take the mower off and return the leveling blade to its rightful spot to be ready for winter snow.

Seems odd if all was set up correctly and things functioning normally that I'd have such unusual results. Clearly, such a device shouldn't be doing what it is designed to do and then come apart in the process. I'm hoping the group might be able to help out this rookie. The help is too late for last season, but perhaps I'll have better luck for next season. Much appreciated.

[tmays]

Lot of moving parts on a sickle mower, so there's alot to look at. Bearings and bushings have to be in good condition. Lead and register need to be correct. Everything should be aligned correctly. Drive pulley should be tight and running true. Pics and video would be great. I know, not possible right now

[danovercash]

Are you using tapered or square shoulder bolts. Tapered bolts are REQUIRED in certain places.

[LeeC]

From my experience, the mower is going to shake the tractor some. This shaking is going loosen bolts that are not rock solid tight. So, the rule of thumb is to run the mower a little, stop and retorque everything, especially on the mower itself. You may have to retorque bolts several times. If the mower is shaking a lot from the beginning, I suspect wear in the drive shaft bushings. Since you have the mower off the tractor, now is a good time to check the bushings by seeing if there is lateral play in the drive shaft (check both front and back). If the mower starts shaking only in heavy grass, check knife register and sharpness of the cutting edges. I have one field that makes my mower shake a lot just because the vegetation is really thick. I suspect my knife head is not being held down tight enough. If the front bracket bolts come loose, the mower will shake very violently. I assume you have the correct implement (cone shaped) bolts for the front bracket? --Lee

[WaMoo]

How fast are you running it? I usually mow in 2nd gear, at half throttle, maybe less. My experience has been that as the grass gets thicker, it runs smoother. As others have said, the tapered implement bolts are a must where required. I'll reiterate to check the lead, slop in the knife, etc. I do hope you get it figured out. A sickle bar is a pleasure to mow with when it's all tuned and running like it should.

[Bob Triplett]

What size pulley do you have on the PTO shaft?

[SONNY]

The sickle is not made to mow grass with. its made to mow hay and weeds with!!--- And shake they will! I have one someone stuck on one of my older cubs, and the thing is junk compared to the one on my ac-c tractor! thanks; sonny

[WaMoo]

I would also recommend looking at GSS-1053, Mower Cutter Bars-All Models; Maintenance and Repair. I thinks it's up above PDF manuals.

Another good generic reference is The Mower, How to Repair and Adjust:

http://ir.library.oregonstate.edu/xmlui ... sequence=1

Consumable cutter bar parts (sections, ledgers, wear plates, etc.) are relatively inexpensive. I've had good luck with Webbs Sickle Service.

Using the advice on this forum, and the references, you should be able to get your mower humming along like a sewing machine!

[HarveyCub]

I managed to find a brief video of the sickle bar in action. Can't seem to attach a video, so here's a link: https://www.dropbox.com/s/wp68zm7q2vu4x ... r.mpg?dl=0
This is fairly early in the run, so this is while things were running relatively smooth. Before the bolts popped...
HC

Lot of moving parts on a sickle mower, so there's alot to look at. Bearings and bushings have to be in good condition. Lead and register need to be correct. Everything should be aligned correctly. Drive pulley should be tight and running true. Pics and video would be great. I know, not possible right now

[HarveyCub]

Not sure that I noticed or perhaps even noticed the difference...I started with whichever bolts the previous owner had with it and did my best to replace when lost. I also didn't notice anything about different bolts in the manual for the L22.

Are you using tapered or square shoulder bolts. Tapered bolts are REQUIRED in certain places.

[HarveyCub]

I would say that I was probably mowing about the same. Tried in first gear at 1/2 to 3/4 and tried in second as well, but certainly no more than 1/2 throttle.

How fast are you running it? I usually mow in 2nd gear, at half throttle, maybe less. My experience has been that as the grass gets thicker, it runs smoother. As others have said, the tapered implement bolts are a must where required. I'll reiterate to check the lead, slop in the knife, etc. I do hope you get it figured out. A sickle bar is a pleasure to mow with when it's all tuned and running like it should.

[tmays]

Well it definitely should not be loading up with grass like that. Is there quite a bit of previously cut dry grass in there? Green grass helps lubricate things. Can't tell from angle of video, but looks like lead needs adjusted? Also register must be correct in order to cut cleanly.

[HarveyCub]

A Browning BK50H I believe. OD=4.75 inches

What size pulley do you have on the PTO shaft?

[HarveyCub]

Thanks to everyone for their sage wisdom thus far. Lots to think about prior spring/summer. I don't foresee needing the sickle bar for much and I don't use for regular mowing. I've only used so far to deal with overgrown grass that had a couple of years to take over a few parts of the property. House sat vacant for some time and the grass resembled hay in some areas...

[HarveyCub]

Unfortunately, no.

Well it definitely should not be loading up with grass like that. Is there quite a bit of previously cut dry grass in there?