Rotary Cutter Blade Nut

[Heavy Metal Doctor]

I love these web discussions.....my answer to torque questions would simply be: RTFB for the given project you are working on....some stuff gets oiled, some stuff gets loctite or never sieze, some things are clean and dry/oil free - fastener and part.......but what do I know, I'm just a mechanic....

 

[banjodunn]

I love these web discussions.....my answer to torque questions would simply be: RTFB for the given project you are working on....some stuff gets oiled, some stuff gets loctite or never sieze, some things are clean and dry/oil free - fastener and part.......but what do I know, I'm just a mechanic....

:thumbsup:x2

 

[zzvyb6]

There's a reason J J is a Super Member. I print off every one of his replies and add it to my Book of Knowledge.

"If you want to be happy for the rest of your life,
Make an ugly woman your wife.

So from my personnal point of view,
Get an ugly woman to marry you."

 

[dwost]

I did mine today. Didn't have a 3/4 driver so I used an adaptor on my 1/2" ratchet. Well, one good pull with a cheater bar attached and SNAP broke the ratchet head. Quick trip to sears, got a replacement free of charge (gotta love that lifetime warranty) and a 3/4" breaker bar. Attached a pipe and with one good tug on each one they broke loose. I lubed em up good with fluid film upon reinstallation so hopefully next change will be much easier. Quick tip, i left it hooked to my tractor to keep it stabilized while I broke them free. I then tipped it up to do the change. Much safer that way too!

 

[9973720wb19]

Aside from how tight the bolts need to be, my understanding is that it's highly recomended to use new hardware (nuts and bolts) each time you change the blades on a rough cut deck. break this rule at will...

 

[Chilly807]

I then tipped it up to do the change. Much safer that way too!

I've heard of folks using a come-along attached to the ROPS and tail wheel frame to pull the cutter up to work on the underside. Nobody I know would do something like that, though..

Sean

 

[dwost]

I just lifted it up by hand onto the 3 point and then secured it with a tow strap to the rafters in my barn. Worked great!

 

[SPYDERLK]

I told you a incorrect torque spec. It is 450 ft. lbs. When you put it back together.

:confused2:That spec must be for a bolt lubricated with moly paste. This is an extremely low torque spec for a 1-1/8 X 12 bolt. This bolts should be Gr5 strength at least. The 8-900 ft-lb range dry would be appropriate on a bolt like that. Do not lube with anything more lubricious than WD40 or Kroil or the torque spec should be lowered 30 or 40%. Problem is, in the Hi impact environment the long term lowered friction of oils, greases, or anti seize will favor them working loose.
larry

 

[Snaker]

A lot of the old cutters had holes in the deck top for access to the blade bolts. Some farmers made holes on their own with the hot wrench. I think most companies have stopped putting in those access holes. Ken Sweet

Thats sad to hear (read?). That access hole was a little extra that I gave cudo's to the manufacturers for doing. Making a hole would definitely be a project on my list. Not only does the hole make life easier, but it adds support to a socket extension to give more straight torque to the nut. I'm assuming that the design still uses a captured bolt with the nut on top?

 

[Snaker]

The interesting thing about Loctite, aside from it's primary purpose, is that very rarely, never in my experience, will a bolt that's been treated with Loctite gall or seize on the threads while being disassembled. It acts as a anaerobic sealer to prevent moisture from finding it's way between the threads and rusting.

Sean

I agree. After time where I started disassembling some of the hardware that I had previously treated with various stuff, I found that anti-seize was somewhat hit-and-miss. Sometimes it worked great and sometimes it seemed to turn to muck and be a hindrance. I have found that on situations where a bolt goes into a threaded through hole and the end is exposed or where a bolt threads into aluminum, that blue Loctite works as good or better as an anti-seize than does the actual anti-seize.

 

[dwost]

Thats sad to hear (read?). That access hole was a little extra that I gave cudo's to the manufacturers for doing. Making a hole would definitely be a project on my list. Not only does the hole make life easier, but it adds support to a socket extension to give more straight torque to the nut. I'm assuming that the design still uses a captured bolt with the nut on top?

Spot on, mine has the hole and when I was leaning into it, it definitely helped to keep the socket and 5" extension straight. Made the overall process much easier.

 

[Degolyerent]

The torque specs are straight from the book 450 lbs it does not say anything about lube, the quality of the pics is poor sorry!!!!

 

[kjung17]

I am really surprised at some of you for using any lubricant on threads and nuts in a torque situation. Just about all torque figures are for dry fit. You can not get away with that on military aircraft, and probably civilian aircraft. I bet they don't do that on the space shuttle either. You can do whatever you want with your own machines, as the risk is yours.

Don't want to argue about it, as dry fit is the rule.

I would, generally, hesitate to contradict a man of JJ's intelligence and experience, but... Tiger brand cutters specify an oiled bolt torque spec (800 ft/lbs) or 1000 ft/lbs dry. Most Deere cutters that I am familiar with use dry torque. To address the tooling issue. I highly recommend a 4:1 torque multiplier. You can apply 1000 ft/lbs with a 1/2 torque wrench. For tough nut removal, use the multiplier with your impact. James Morton X-4 Torque Multipliers manufactured by X4 Division of Gear/Tronics Industries Incorporated
I would not recommend reusing hardware. 450 ft/lbs does seem low for that application. RTFB??

 

[RoyJackson]

I would not recommend reusing hardware. 450 ft/lbs does seem low for that application. RTFB??

My Land Pride calls out 433 ft-lbs (doesn't say lubed or dry, so it defaults to dry), so I don't think 450 ft-lbs is low.

Although my earlier post stated I dry torque and have never seen a spec calling out a lubricated torque, I do use an anti-seize. Not as a lubricant, but as a barrier against corrosion.

 

[kjung17]

My Land Pride calls out 433 ft-lbs (doesn't say lubed or dry, so it defaults to dry), so I don't think 450 ft-lbs is low.

Although my earlier post stated I dry torque and have never seen a spec calling out a lubricated torque, I do use an anti-seize. Not as a lubricant, but as a barrier against corrosion.

The Tiger machines may be an exception for the oiled torque spec. As I see them regularly, it seems common to me. The lowest torque that I found for Deere was over 600 ft/lbs. I'll have to look at the specs on the frontier cutters, out of curiosity. I'm sure it depends on the weight of the blade and type of fastener. Good discussion.

 

[SPYDERLK]

The idea is to have enuf clamping force to prevent the joint from moving at all while it is in use. In this case use involves being hammered on by incidental, somewhat frequent, circumstances. A 1-1/8 X 20TPI grade 5 bolt is rated for 900 ft-lb dry. On a figurative scale, at 450ft-lb, a bolt like this is somewhere between finger tight and "snug". I had one work loose after being tightened to stall with my 600ft-lb IR Titanium on a short 130psi air line. After this I have always 1st used the Titanium to stall and then used the IR 261 3/4" for about 15 hits. It tightens about 1/20th turn further. No more trouble.
larry

 

[Gary Fowler]

The last time I worked on a mower, I just took the FEL and turned it up on its side. Then took the whole stump jumper off by removing the center nut It was then easy to remove the nuts from the blades. It was a good thing at that point because the whole blade fastener assemble had broken the weld on one side right at the splined hub and had to be beveled out an rewelded. The only thing holding the whole thing together was the stump jumper. It is a good idea to remove the whole assembly when doing a blade replacement to inspect the hub and all components anyway and much safer that way if you have a way to lift it up on it side. I used a pry bar in the u-joint to block the blades from turning and the one nut was easy to remove. Once off, the blade fasteners were easy to work on also.