Bush Hog Blades

[Turbys_1700]

Several weeks ago I replaced 4 blades on our 10' Howse Rotary Cutter...
The old bolts that attached the blades to the stump jumper utilized a lock washer to tighten the bolts...
I went ahead and purchased 4 new bolts with the blades and low and behold, the new bolts have castle nuts with carter pins for securing the blades...
I do have a problem though...
As tight as I can get the bolts, only 1/2 of a hole is showing through the bolt for the carter pin...
My only solution that I can see is to take the stump jumper off and grind down the stump jumper attachment bars...
That would give me enough tolerance to put in the carter pins...
I am thinking that my easiest option would be to utilize lock washers on the new bolts and call it a day...
Any input and thoughts would be appreciated...

 

[SoGeorgia]

Several weeks ago I replaced 4 blades on our 10' Howse Rotary Cutter...
The old bolts that attached the blades to the stump jumper utilized a lock washer to tighten the bolts...
I went ahead and purchased 4 new bolts with the blades and low and behold, the new bolts have castle nuts with carter pins for securing the blades...
I do have a problem though...
As tight as I can get the bolts, only 1/2 of a hole is showing through the bolt for the carter pin...
My only solution that I can see is to take the stump jumper off and grind down the stump jumper attachment bars...
That would give me enough tolerance to put in the carter pins...
I am thinking that my easiest option would be to utilize lock washers on the new bolts and call it a day...
Any input and thoughts would be appreciated...

Yeah.. If you never had a problem before just using lock washers I say just get some washers and crank them down tight.. I also use loctite but that's just the way I do it.

 

[LD1]

It would be easier to either shave a bit off the nut, or take a little air cut-off tool and cut down a bit of the castle's that's blocking the hole.

Few other suggestions...how tight is "as tight as I can get"??? And was that dry?? if so, add a little never seize or oil and try again. May get just enough.

Also, perhaps try re-arranging nuts and bolts around. Different combinations may be machined slightly different.

 

[SPYDERLK]

Find a nail that will almost fit thru the available open hole. Tap it thru.

 

[Turbys_1700]

Thanks for the help guys...
I am torquing those puppies down with a 3/4" drive air impact wrench rated @ 950 ft.lb...
After that I am putting a 20" long 3/4" drive breaker bar with a 36" pipe attached for leverage...
The bolts are tight as can be after the air impact and If I was to put any additional pressure on the breaker bar I could easily demolish it...
I pull down on it until I feel the breaker bar start to give...
I believe that my impact is delivering very close to 950# of torque...

 

[LD1]

It is possible you are over torquing them.

The bolts on my bushhog 306 (which takes a 1-11/16" socket) only have a torque spec of 450 ft-lbs.

I am guessing 950 is a tad much.


IF you have a way to measure (or guesstimate closely), use your breaker bar and cheater pipe and only apply about 100-120# of force at a distance of 48" from the center of the socket head. That should get you over 400#. and with a castle nut, that should be more than enough.

 

[mikehaugen]

Are you using the lock washer still?

Dumb question maybe, but I had to ask.

...Also, they are cotter pins. Not that it matters though.

 

[gunmonkeyintl]

Thanks for the help guys...
I am torquing those puppies down with a 3/4" drive air impact wrench rated @ 950 ft.lb...
After that I am putting a 20" long 3/4" drive breaker bar with a 36" pipe attached for leverage...
The bolts are tight as can be after the air impact and If I was to put any additional pressure on the breaker bar I could easily demolish it...
I pull down on it until I feel the breaker bar start to give...
I believe that my impact is delivering very close to 950# of torque...

Pardon my shock/ignorance, but WTF did you come up with that procedure?
You have a driver that provides a (somewhat) known torque, and then you go to a breaker bar and wait for it to "start to give" - what exactly does that feel like, anyway?

I'd check your torque specs in the manual (or a standard chart for your hardware size) and roll with that. 950 seems way high for an application like that. $0.02

 

[mikehaugen]

I think he was just trying to demonstrate that he could not get them any tighter and it still wasn't tight enough to expose the hole. I think air tool ratings are pretty optimistic anyway, especially since they are usually reverse biased and apply way less torque in forward.

I would have to check, but aren't the blade bolts spec'd a lot lower than the center stump jumper bolt? I think that 450 figure is for the center bolt.

 

[Ford850]

Why don't you just cut the slots a little deeper on the castle nuts so the hole in the bolt will be exposed?

 

[SPYDERLK]

You mean wider?

 

[SPYDERLK]

It is possible you are over torquing them.

The bolts on my bushhog 306 (which takes a 1-11/16" socket) only have a torque spec of 450 ft-lbs.

I am guessing 950 is a tad much.


IF you have a way to measure (or guesstimate closely), use your breaker bar and cheater pipe and only apply about 100-120# of force at a distance of 48" from the center of the socket head. That should get you over 400#. and with a castle nut, that should be more than enough.

I really cant figure out why anybody would think 450 on a 1"+ hi strength bolt was tight. :confused2:

 

[Turbys_1700]

Pardon my shock/ignorance, but WTF did you come up with that procedure?
You have a driver that provides a (somewhat) known torque, and then you go to a breaker bar and wait for it to "start to give" - what exactly does that feel like, anyway?

I'd check your torque specs in the manual (or a standard chart for your hardware size) and roll with that. 950 seems way high for an application like that. $0.02

I come up with that procedure from living 54 years on the farm and working on equipment all my life...
Anybody that has used breaker bars long as I have know when they are at their limits based on the pull...
I know what it feels like...

I would like to thank everyone for their input...
I will go with a lock washer and lock-tite...

 

[Ken45101]

Why do you want them so tight?

Yes, with a lock washer, you need it tightened down. But with a castle nut and cotter pin, I would think that the last hole you can reasonably access would be fine. The blades are supposed to swing freely.

 

[LD1]

I would have to check, but aren't the blade bolts spec'd a lot lower than the center stump jumper bolt? I think that 450 figure is for the center bolt.

Nope. Thats Bushhogs spec for my blade bolts. Not the center stump jumper bolt.

Actually the manual (like alot of manuals) lists a generic torque chart in the back cased on fastner size. And the 1-1/8"-12 (which is what the blade bolts are) spec is 890 ft-lbs for grade 5 and 1444 ft-lbs for grade 8. and a 1-1/2"-12 like my stump jumper lists ~2100 and ~3500 ft-lbs respectively.

So the 450 ft lbs for the blade bolts, is way under what the bolt can actually handle.

 

[LD1]

I would have to check, but aren't the blade bolts spec'd a lot lower than the center stump jumper bolt? I think that 450 figure is for the center bolt.

Nope. Thats Bushhogs spec for my blade bolts. Not the center stump jumper bolt.

Actually the manual (like alot of manuals) lists a generic torque chart in the back cased on fastner size. And the 1-1/8"-12 (which is what the blade bolts are) spec is 890 ft-lbs for grade 5 and 1444 ft-lbs for grade 8. and a 1-1/2"-12 like my stump jumper lists ~2100 and ~3500 ft-lbs respectively.

So the 450 ft lbs for the blade bolts, is way under what the bolt can actually handle.

 

[SPYDERLK]

Why do you want them so tight?

Yes, with a lock washer, you need it tightened down. But with a castle nut and cotter pin, I would think that the last hole you can reasonably access would be fine. The blades are supposed to swing freely.

The joint is made by a shoulder bolt seating in a fitted socket. Joints can move. If they move they wear and get loos[er] without the nut turning. All parts in a joint that wear are then damaged and consequently less sutable for their purpose. Ample tightness will keep the joint from moving.
larry