Rotary Cutter Rotary cutter not cutting.

[N80]

I've been using an old 'loaner' rotary cutter that my brother-in-law has but doesn't use. Its a 7' heavy duty JD pull-type and it worked great last weekend. Never hit anything big, never scalped or anything. Today when I hooked it up I checked the oil in the gearbox as my in-law recommended. Dry as a bone. Last week it was fine.

So, I fill it with gear oil. Check the dip and its fine. Off I go to mow some very light fescue. I adjust mowing height with the remote, I engage the PTO and take off but when I look behind me the grass isn't mowed. I can see the blade spinning but not fast. I get the rpms up to proper level and still nothing.

Then I put tractor in neutral, flip up the seat to keep PTO and engine running and hop down to look at the slipper clutch and it does not appear to be slipping at all. Not knowing anything else about this mower I gave up. I checked the gear box about 3 hours later and it was still full. I looked underneath and there was gear oil all over the blade shaft but I can't imagine how that would cause the problem.

Now, I know I got a leaky gear box to deal with. But anyone have any idea why the blades would turn, but not with any force or speed, even when the rpms where up. Is there any other type of clutch? And if there was a shear pin that was sheared, would the blades spin at all?

Thanks for any thoughts.

 

[slowrev]

could be a shear bolt gone in the driveline , or where the slip clutch hooks up ?

Any nasty noises coming from the gearbox ?

Ben

 

[N80]

No unusual noises except you don't hear the normal blade noise. My brother-in-law wasn't home so I'll have to check with him. It has been a bit of a money pit so neither one of us is going to wan't to sink in more money into it.

 

[beenthere]

When you say "it has been a bit of a money pit.....", what do you mean? What has taken the 'money' ?

I'd hope for the shear bolt failure, but have some suspicion it may be the gear box. Has the gear box been worked on (i.e. money pit) ?

 

[Soundguy]

IF the pto shaft from the tractor IS spinning.. AND the mower slip clutch IS spinning, and the shaft going into the gearbox IS spinning.. but the blades aren't really cutting.. AND it has an oil leak.. I'd guess output shaft problems.. bad seal for sure.. and maybee a loose stump jumper / blade carrier// perhaps a sheared keyway.. or worn splined hub, depending on styles... Could also be sheared output shaft. This of course assumes pto clutch in tractor is not slipping.. and slip clutch is not slipping.

Sorry to hear of your troubles. I know you have been round and round on this mower issue with nothing but red flags so far /forums/images/graemlins/blush.gif

Hopefully you will find something easy like a bolt tieing the slip clutch to the input shaft shorn but dragging .. and the seal was leaking due to non use.. etc.

On some old cutters.. many people use a combination gear oil and grease to help old deasl.. or a pourable grease like JD corn head oil... especially if it is a throw away mower.

Also.. some mowers simply spec grease instead of gear oil anyway. my howse mower will use either...

Also.. whaen adding gear oil.. Usually you don't fill them all the way up especially if there is no vent, as the pressure build up will do things like blow seals out.. etc.

Soundguy

 

[N80]

Red flags indeed. My in-law picked it up for about $50 (red flag #1) but he likes a bargain and a challege. I pitched in about $350 to rebuild the gear box. He got it running about 9 months agao after a number of setbacks and hit a huge stump in some blackberries that broke the tongue off the trailer mount! A little more money, some welding, more work on the gear box and things were back to where they were last weekend. We were both psyched that it ran so well and that my tractor could handle it. Now this. You know what they say about free rides.

I don't have much money in it, but he has a bit more than me and a lot more time. Could've bought new low end cutter for what we have in it...but that's not his style.

I'm ready to bail. There's a used Woods 6' that was used maybe twice and looks new at a local shop. I think I'm going to look at that.

Oh, I didn't overfill it. Filled all the way up to the 'full' line on the little plastic dipstick and no more.

We're considering an exorcism at this point. Or maybe something involving explosives.

 

[have_blue]

Just a shot in the dark: Maybe some gear oil got on the slip clutch (if you have one!) and caused it to slip until it wore down. If th eslip clutch is oily and shows signs of slipping a lot, clean it with solvent and tighten it up. If it doesn't have a slip clutch, maybe it's the shear pin. If not it's that, well, hide your wallet. /forums/images/graemlins/frown.gif

 

[Soundguy]

Sounds like an awefull lot of work on the gear box. I'll assume new seals and bearings?

perhaps something is reallt worn in the gear box and the bearings went out again / seals went out.. gears are backed off?

Also.. sounds like the slip clutch is misadjusted or stuck if it did not function when the stump was encountered.

Sorry about the luck so far /forums/images/graemlins/frown.gif

What's the $$ deal on the 6' mower if you don't mind me asking. My point is.. it may be enough $$ to get you a slightly larger mower 'new' from a '2nd' brand.. like howse.. that is.. if you were looking for wider than that 6' used one.

However.. if the 6' is a great price.. go for it.. nothing like letting someone else take the depreciation hit on equipment for you! /forums/images/graemlins/grin.gif

let us know how you make out.

Also.. even if you do get the new mower.. pop the top on the old one and see what died. I'm curious if it was inthe lower end.. like a hub/blade carrier/ and bearing / seal issue.. or if it was in the front end like drive gear..e tc..

Soundguy

 

[N80]

This 'stump' was so big it didn't go under the mower. Apparently it barely cleared the underside of the tractor (a big old Case) but caught the mower at the upper deck and left skid. Apparently the hitch was quite rusted out becsue he said he didn't even feel a big jerk. (He did feel _like_ a big jerk, though).

I didn't help with the gear box but the initial problem was that this was some sort of high RPM gear box and he bought new, lower rpm gears for it. Those have worked fine until now except for another leak which required some work, but obviously wasn't fixed. I don't think his heart has been in this project.

He probably has 8 or ten tractors of various sizes and configuration. i'd guess the newest one was from the early 80's. He loves old stuff and doesn't mind working on it (constantly) to keep it working. I've never seen a new bailer, rake, tractor, hay mower, rotary cutter, truck or horse on his farm in the 25 years I've known him.

I couldn't live like that.

I'll check on the price of the Woods today.

 

[Soundguy]

Sounds like he converted it from a 1000rpm pto to a 540 rpm pto.

Those hitch holes DO get wallowed out from regular use.. I don't doubt that snagging a stump would rip it threw.. especially with any rust.. etc.

Soundguy