Rotary Cutter Question

[Bluesteel]

I recently bought a used 6' TSC rotary mower. Almost new condition. Guy only used it about 20hrs mowing down grass a couple times for a new home. It probably wouldn't be my first choice but I couldn't pass it up for 1/2 price. I'm only cutting pasture grass and very few small saplings so I figured it would do what I wanted. Used it several hours yesterday. Mower operated and cut good. It has shear bolt which after I replace it about 5 times I'm not much a fan of. One time I hit an old tractor inner tube which sheared it, no big deal. Couple other times didn't hit much at all and it sheared. #2 grade shear bolt.

Now to my question. I have some oil coming out of the gear case vent plug. Not much but it does run down the outside of the gearbox onto the deck. I checked the gearbox and it does have oil, maybe too much? Or is the vent plug bad for some reason? I put Teflon tape on the threads before I used it. I did not add any oil as the gearbox was full. The oil is coming out of the vent and not the threads. Anyone else have this problem? Thanks.

Probably going to add a slip clutch. Also, I think the cutter has an abrupt engagement when you hit the PTO at low rpms. It's pretty smooth when mowing, no shaking. I'm thinking it has to do with the blades being slung out.

 

[HCJtractor]

I don't think the gearbox needs to be full. I would try to find an owners manual online and see what level the gear oil needs to be. Probably about half full.

 

[JBob]

Too much oil. Most boxes are 1/2 to 3/4 full.

 

[HEC]

There should be an overflow plug on the side of the gear box , takes an allen wrench on my bush hog . On my Kubota tractors I have a pto lever which I can slowly engage so you don't get that abrupt start up , not sure what your set up is .

 

[Bluesteel]

I was thinking probably too much oil. I do have the owners manual. I know there is a smaller plug about half way up the gearbox. I believe that is the level it is suppose to be at. HEC, mine is an electric actuated PTO so there no way to feather the PTO on. It seems so violent on start up I'm shocked it doesn't shear the bolt. Thanks for all the quick replies.

 

[Turbys_1700]

I was thinking probably too much oil. I do have the owners manual. I know there is a smaller plug about half way up the gearbox. I believe that is the level it is suppose to be at. HEC, mine is an electric actuated PTO so there no way to feather the PTO on. It seems so violent on start up I'm shocked it doesn't shear the bolt. Thanks for all the quick replies.

You are correct on the side level fill plug. Usually gear box fill level covers half the input shaft. Vent is working properly. Gear box was probably overfilled.

Your PTO operates like an independent PTO. Either on or off. No way to feather it to my knowledge.

 

[Baby Grand]

You didn't say how old it is - only hours of use. The reason I bring this up is that if it sat outside for a winter or two, even if it was under cover, there's a good chance that the oil level is too high due to water in the oil, from condensation. The water will sit at the bottom of the gearbox until the unit runs, when it will mix with the gear oil. If the gearbox hasn't spun for a day or two, draw some fluid off the bottom of the gearbox by using a tube and a vacuum pump, syringe, turkey baster, whatever you can find. Take a good look at that oil & see if it has any water in it. If it does, then empty the gearbox completely and refill with the oil specified in the owner's manual.

 

[Bluesteel]

You didn't say how old it is - only hours of use. The reason I bring this up is that if it sat outside for a winter or two, even if it was under cover, there's a good chance that the oil level is too high due to water in the oil, from condensation. The water will sit at the bottom of the gearbox until the unit runs, when it will mix with the gear oil. If the gearbox hasn't spun for a day or two, draw some fluid off the bottom of the gearbox by using a tube and a vacuum pump, syringe, turkey baster, whatever you can find. Take a good look at that oil & see if it has any water in it. If it does, then empty the gearbox completely and refill with the oil specified in the owner's manual.

About 1 year old. I drained at least 16 oz of oil out of the gearbox until it was just a trickle out of the small hole. The oil looked good. Very good point on the condensation. I will let it sit a few days and draw some oil off. I take it to drain the gearbox you have to suction the oil out? Thanks for the great info.

 

[jaydee325]

I'm guessing you TSC cutter is probably made by Taylor Pittsburgh like my LS cutter is. If you have the manual, it will tell you how to check the oil level.

Mine says remove the vent plug, and remove the plug on the side of the gear box. Gearbox should be fill just until oil flows out the side plug. If you pull the side plug and oil gushes out, it is over filled.

Are you engaging the PTO with the engine at PTO speed? That will damage sheer pins as well as other expensive parts. My LS R3039R manual says to engage the PTO at idle. Then slowly increase engine speed to PTO speed.

 

[Bluesteel]

I'm guessing you TSC cutter is probably made by Taylor Pittsburgh like my LS cutter is. If you have the manual, it will tell you how to check the oil level.

Mine says remove the vent plug, and remove the plug on the side of the gear box. Gearbox should be fill just until oil flows out the side plug. If you pull the side plug and oil gushes out, it is over filled.


Are you engaging the PTO with the engine at PTO speed? That will damage sheer pins as well as other expensive parts. My LS R3039R manual says to engage the PTO at idle. Then slowly increase engine speed to PTO speed.

The TSC cutter looks the same as a Tarter more than the Taylor/Pitt. I drained oil to the appropriate level so I think I have that taken care of. I'm engaging at idle rpm. The electric actuated PTO makes for the abrupt start. Have to live with that I guess. Not sure if the slip clutch would help with that or not.

 

[fixitman123]

Bluesteel, great find on that cutter at 1/2price. Have you considered a harder sheer bolt. I wouldn't think it should shear so easily. I had a small boat motor that would sheer the pin if you looked at it wrong! I got a harder pin and don't think I ever had to replace it again.
Check out http://www.tractorbynet.com/forums/ls-tractors/255173-shear-pin.html

 

[oscar169]

I would not go with a Hardened bolt, the shear bolt is b/c you don't have a slip clutch?? I was thinking all Brush Hogs had slip clutches, If not I would dump it as soon as possible, will get old real quick changing that bolt all the time and if you go with a Hardened bolt you risk damage to the PTO on tractor,

 

[Bluesteel]

I would not go with a Hardened bolt, the shear bolt is b/c you don't have a slip clutch?? I was thinking all Brush Hogs had slip clutches, If not I would dump it as soon as possible, will get old real quick changing that bolt all the time and if you go with a Hardened bolt you risk damage to the PTO on tractor,

Yes, there is no slip clutch (yet) and yes it gets old replacing that bolt. I don't want to use more than a grade 2 bolt for fear of damaging the PTO on the tractor. I can get a slip clutch that bolts between the gear box and PTO shaft for about $120 through Agri Supply. I found one local for $150 at our farm store where most items are over priced. I would think you would use a harder bolt than a grade 2 to bolt the clutch on. Probably a grade 5?

 

[stuckmotor]

My mower was shearing bolts like crazy, until I realized the bolts I was using were one size too small. Enough said.

 

[oscar169]

Yes, there is no slip clutch (yet) and yes it gets old replacing that bolt. I don't want to use more than a grade 2 bolt for fear of damaging the PTO on the tractor. I can get a slip clutch that bolts between the gear box and PTO shaft for about $120 through Agri Supply. I found one local for $150 at our farm store where most items are over priced. I would think you would use a harder bolt than a grade 2 to bolt the clutch on. Probably a grade 5?

Man if you got a really good deal on the Brush Hog then you better of getting the slip clutch and just be hogging away with no worries

 

[bumperm]

Grade 5 is often spec'd for shear bolts rather than softer bolts, just don't use grade 8. Problem with softer bolts is that upon failing, the sheared ends tend to smear or wipe as the metal flows. This sometimes makes it more difficult to remove the pieces. Grade 5 shears cleanly.

 

[Bluesteel]

It looks like you install a slip clutch using grade 8 bolts. Several listed come with the bolts. Thanks for all the info.

 

[HEC]

There are pros and cons to shear bolts and slip clutches . Slip clutches must be adjusted properly in order to do their job correctly . They need to be adjusted each season and after not being used for a time , if not the clutches can stick together . I have slip clutches on both my cutters and find it a pain , just my opinion , if I was replacing shear bolts all the time that would be a pain also , but much easier , and knowing they were always ready to do their job. If I let my slip clutches set for a month or so not being used I always wonder .

 

[Bluesteel]

Little update. After draining the excess oil out of the gearbox no more oil came out of the vent. Problem solved. I used it a couple hours and never sheared a bolt (I never hit anything). I was almost done and moved to mow a small area. Engaged the PTO and bam, sheared the bolt. Needless to say I have a slip clutch coming. Done with the shear bolts. They are no good if you can't even engage the cutter without shearing it. I found a brand new clutch (Eurocardan) on ebay shipped for less than half price.

 

[jaydee325]

Little update. After draining the excess oil out of the gearbox no more oil came out of the vent. Problem solved. I used it a couple hours and never sheared a bolt (I never hit anything). I was almost done and moved to mow a small area. Engaged the PTO and bam, sheared the bolt. Needless to say I have a slip clutch coming. Done with the shear bolts. They are no good if you can't even engage the cutter without shearing it. I found a brand new clutch (Eurocardan) on ebay shipped for less than half price.

I'm surprised you've sheered so many pins. I've sheered three on my LS 72" cutter and all three were from hitting good size 4" - 6" logs lurking in the overgrowth. I've even grounded the blades and bogged the engine down before getting my hand on the lift lever to get the cutter off the ground and not had the pin sheer.

I'm using generic grade 2 bolts.