Rotary Cutter newbie bush hog question

[rsmith02184]

hi

i am a city boy trying to figure out all this farm stuff. i have a JD 4100 HST Utility Tractor. i recently bought a VERY used 5' bush hog type mower. a few questions:

1) the drive shaft is completely frozen and won't extend. i tried hooking it up to a tree and my tractor/truck and i could not get it apart. is my only option to buy a new drive shaft?

2) i greased all fittings and i checked the gear box. it had oil up all the way up to the fill bolt when i believe it is only supposed to be filled up to the fill line. should i lower it to the fill line instead?

3) i have never dealt with the smooth connector on the gear box for the drive shaft. do i have to put a shear bolt in where the drive shaft joins the gear box or will any bolt do? if i need a shear bolt, what type do i get.

any other advice before i connect it to my tractor and use it?

thanks

 

[foggy1111]

hi

i am a city boy trying to figure out all this farm stuff. i have a JD 4100 HST Utility Tractor. i recently bought a VERY used 5' bush hog type mower. a few questions:

1) the drive shaft is completely frozen and won't extend. i tried hooking it up to a tree and my tractor/truck and i could not get it apart. is my only option to buy a new drive shaft?

2) i greased all fittings and i checked the gear box. it had oil up all the way up to the fill bolt when i believe it is only supposed to be filled up to the fill line. should i lower it to the fill line instead?

3) i have never dealt with the smooth connector on the gear box for the drive shaft. do i have to put a shear bolt in where the drive shaft joins the gear box or will any bolt do? if i need a shear bolt, what type do i get.

any other advice before i connect it to my tractor and use it?

thanks

Unless you can get that drive to operate smoothly....telescope freely and the U joints loosened up......I think you will need to replace it.

Typically gear boxes are partially filled and most manufactures warn about over-filling. I would drain some off to the fill line (.....but I wonder why it's over filled? ).

A shear bolt is typically a grade 2 bolt (not hardened) and thats what I would use. Also, you should have a groove in the stub end that connects your PTO shaft on the gear box. This groove is designed to accept a retaining ring (split ring) that in the event the shear bolt breaks the pto will not fly off the shaft and wrap around the cutter......or you.

 

[Gary Fowler]

If it has the safety plastic shrowd on it, start by cutting that off. IF you split it lengthwise, you can reattach it with ty-raps. Then you could try heating the end where the square shaft mates up to the other section for a distance of about 6 inches from the end and then with the shaft held vertical, apply some regular candle wax and let it melt down into the space. Try pulling it apart before it cools. It is likely just a bunch of grease and dirt and rust welding the thing together. I assumed that you had already attacked the problem by using penetrating oil at the slip joint. If not try this first.
The shaft on my bushhog was impossible to move and I fixed it by just splitting the plastic safety shield. Now if moves with one hand.
If you get it apart, keep it well greased from now on. THe female shaft portion should have a grease zerk so you can apply grease often to the shaft. if not just extend the shaft and slather some on the male shaft by hand and slide it back in. If you remember to slide the shafts together each time you unhook, that will protect the male shaft from rusting also.

 

[rsmith02184]

the shaft did not come with a plastic sleeve. that is probably why it froze up being exposed to the elements with no protection.

i hit it with penetrating fluid as well as with lube and a torch and it didn't budge.

question #1) is there any way i can use the drive shaft to my finish mower? is there an adaptor that i can put on the stub to the gearbox of the bush hog so that i can use the shaft from my finish mower?

i don't know why it was over-filled. question #2) is there usually a reason other than owner error?

thanks again

 

[foggy1111]

the shaft did not come with a plastic sleeve. that is probably why it froze up being exposed to the elements with no protection.

i hit it with penetrating fluid as well as with lube and a torch and it didn't budge.

question #1) is there any way i can use the drive shaft to my finish mower? is there an adaptor that i can put on the stub to the gearbox of the bush hog so that i can use the shaft from my finish mower?

i don't know why it was over-filled. question #2) is there usually a reason other than owner error?

thanks again

Don't operate that PTO without the safety shield in place and operating correctly. Lots of people been hurt pretty bad by uncovered PTO's. If you dont have one....and yours is all froze up and you cannot fix it.....then IMO you either should buy a new one or find a good used one to replace it.

If your finish mower pto shaft is of similar length there is no reason that cannot be used. Check the shaft sizes to verify the fit to the gear box...but they are typically the same size. Do you have a shear bolt on your current finish mower? If so, then you should check to be certain you have at least 6" of overlap between the female and male shafts when connected to the tractor and that the m/f shafts will not "bottom out" when operated.

Its a bit of a pain if you need to change the pto shafts....especially on a regular basis......but it can be done. Maybe this is the best way to check this piece over, before investing in a new (or used) replacement PTO.

NOTE: Just so your know......that "plastic sleeve" is not designed to be a "weather protector". It is designed so that any accidental contact by your or your clothing does not instantly wrap you up and pull your arms or legs off. I don't like playing "safety police" - but an unprotected PTO shaft is something to not take lightly.

 

[rsmith02184]

thanks again for the good info. i didn't think about that protective shield preventing injury. it makes sense!

regarding using my finish mower drive shaft: the question i have is that the bush hog has a smooth rounded stub at the gearbox on which i would connect the drive shaft. my finish mower is a woods and is not smooth, it has indexes.

would my drive shaft be able to grip the bush hog well enough to run the mower? i think it would just slip and spin. my present mower does not use a shear pin at all.

what do you think?

 

[foggy1111]

If you have a "spline" connection on your finish mower then it's not gonna work. You will need to get a proper joint to fit snugly on that round shaft and use a shear bolt to finish the coupling. I dont know of an "adaptor" like what your needing....possibly they do make something like that....I dont have any experience with one.

Instead, IMO.....if you cannot get your cutter's PTO free then you need to try the wax method above.....take it to someone for repair and get a shield for it.......or buy a replacement PTO (which is going to set you back about $200 if you buy it new).

Is this cutter you have worth spending the money on a new or used PTO shaft? I would imagine a used shaft to be worth 1/2 the price of new....if you can find one.

 

[jenkinsph]

Just a thought but if you replace the pto shaft consider getting one with a built in clutch. I agree though you have to decide whether the old cutter is worth it. Another thing to consider is that most shearbolt designs have an oval shaped plate to put the replaceable shear bolt in, the bolt to the gearbox is used to hold the driveline in place. The exception being the ones with the snap ring retainer and groove. If the deck is in decent shape and the gear box is good a new clutch type pto shaft would be a nice upgrade.


Steve

 

[eastexan]

Years ago, I bought a used 5' HiCo cutter from a guy to use with my 9N.
When I got it home and went to hook it up, the shaft wouldn't budge.

Come to find out, the shaft was not only seized, but it was also twisted. So after some heating & beating, cutting some of the shaft off, and greasing it up good, I was able to use it.
I had never seen one twisted before, and figured the guy must have been using it with a bigger tractor than it was designed for.

Needless to say, after that I started looking things over a little better when I'm shopping around.

Ronnie

 

[kthompson]

eastexan, no shear bolts fits with twisted shaft.

You really need to be 100% sure you have the proper length PTO shaft. Too short and it can come apart and damage something or someone; too long and it can jam and damage tractor and or cutter gear box. The shortest distance is when you have the PTO shaft on tractor and cutter level with each other. The shaft must collapse to at least this length or little less. Then as someone has mention it should be about 6 inches of over lap when the lift is fully up and fully down when the shaft length will be at the longest point. They also make different strength PTO shafts.

BTW, congratulations on the move to the country. There is nothing any finer than on a warm night laying on your back looking at the stars with a young child.