Do I need a torque multiplier to get these nuts off?

[pclausen]

I got a Bush Hog 3209 cutter, and I'm trying to get the 1 5/16" bolts off that holds the blades on as I'm replacing them.

The 4 nuts have been soaking in PB blaster for a week, but neither my 3/4" impact wrench (being feed from a 1/2" hose @ 150 psi), nor my 3/4" ratchet with an extension will break any of them free.

I spoke to my dealer about it and they use a torque multiplier in the shop for getting bolts like that loose. Here's a link to one that takes a 3/4" input:

Central Tool 6387 4:1 Torque Multiplier : Amazon.com : Automotive

Does anyone have any experience with these devices? For that price, I wonder if I would be better off getting a monster 1" impact wrench? On the other hand, it would be nice to be able to accurately torque large bolts.

Any other thought on how to break these nuts free? I'm have reservations about using heat given that the bolt are hard to get to and I don't want to cause damage to anything else.

 

[whistlepig]

A little heat will go a long way on removing frozen nuts and bolts. Heat it quick so the heat doesn't have time to travel to areas that can be damaged (seals).

 

[300UGUY]

A little heat will go a long way on removing frozen nuts and bolts. Heat it quick so the heat doesn't have time to travel to areas that can be damaged (seals).

A lot of bolts like that have loctite on them. Heat will break the locktite bond. A fastener that large with loctite on it is really hard to remove. I have had 1 inch plus bolts that I could jump on a 4 ft cheater bar, and it wouldn't budge. A little heat, and it came off easily.

 

[JD 4520]

A little heat will go a long way on removing frozen nuts and bolts. Heat it quick so the heat doesn't have time to travel to areas that can be damaged (seals).

Heat is your best answer. I assume you haven't had these off before. I wouldn't spend the money on a larger impact wrench.

 

[Leejohn]

Are you sure they are right hand threads?

 

[Zebrafive]

I would go the torque multipler route. You might find a used one on ebay. They do work! You just need something to brace the multipers handle against (it wants to turn the opposite way).

What is the torque spec of the nuts? 400-600 lb-ft?

Also consider other uses. What's the torque spec for your loader mounting bolts? If IRCC mine are 390 lb ft and my torque wrench only goes to 200 lb ft. With a multipler set it at 96 lb ft and get 384 lb ft out, probably some losses so set it at 100 lb ft and get close to 400 lb ft out.

Or just get a longer pipe

 

[whistlepig]

May be getting close to an irresistible force meeting an unmovable object here.

 

[dstig1]

Like all too many main crank pullies on engines.... I have laid into these with a large impact wrench, sometimes for 20+ minutes, ad long as your compressor can keep up. Heat is the only other good option. Don't be afraid to hammer that impact on it for extended time. Ear myffs help a litfor that....

 

[Willl]

Some rental yards rent torque multiplers.

 

[v8only]

Are you sure they are right hand threads?

this.

 

[Rustyiron]

Heat the nut. Don't worry about damaging any seals, the seals are to far away from the nut with to much steel in between the two. It is not uncommon to replace (sacrifice) these 4 bolts.

 

[deere5105]

Another vote for heat. I take mine on and off annually to sharpen blades just to make sure they will come off. Could sharpen blades on unit, but get better edge in vise.

 

[flusher]

Use heat on the bolt. Don't worry about messing up something--it's a brush hog that's built like a tank.
As a last resort, tilt that beast up so you can get to the stump jumper and use an angle cutter with cutting blade to cut through the head of that bolt such that you cut the mower blade off. Then cut the shaft of the bolt to get it off the stump jumper.

Good luck.

 

[puckgrinder85]

You're using impact sockets right? A lot is lost through extensions and unsufficient sockets too. But yea, heat is #1 thing to use. Ask any automotive shop, most guys there should be torch pro's due to the amount they get used.

 

[gwdixon]

OK, I'll bore you with another vote for heat but...use an acetylene/oxygen torch and heat the nut to a dull red. Then throw the impact wrench on it and the nut will spin right off.

Heating those nuts will not damage anything. The seals are far enough away as others have mentioned. However, the area, nuts, and bolts will stay very hot for a long time. Best let them cool down on their own. Have lunch, a few beers, or whatever for an hour or so.

On the impact wrench...some of the cheaper wrenches, even in 3/4" or 1", won't do the job like a 1/2" quality (read $$$) impact wrench. Been there, done that.

Edit: And when you put the nuts back on just let the impact wrench rattle on them for a couple of minutes. The torque will be perfect then. :thumbsup:

 

[Tractor Seabee]

If heat does't work, cut them off with a torch or grinding wheel. First time I took off my LP blades I had to use heat. My manual says use new bolts and nuts each time as the self locking threads are one timers. If forced to reuse I would put back on with "Locktite". I keep a spare set of blades, bolts and nuts. My 3/4 drive 6 point socket and torque bar work good. Run them up snug w/a !/2 drive impact w/ adapter and torque down the nuts with the bar. My LP nuts are 1 7/16 for some reason.

 

[Cigar Face]

stop fartin around and cut them off. im an old man but as my old man would always say, "use your head for something other than a hat rack"

 

[swick1]

A mapp gas torch is cheaper than o/a for small projects. Lowes has an oxy mapp setup you could try too.

 

[whistlepig]

That's not a very handy place to cut something off. I have a 600 ft pound impact wrench that I run at 150 PSI. If the bolt or nut has Loctite on it the impact wrench isn't going to budge it. That is what Loctite is supposed to do. It doesn't take much heat to soften Loctite. If I remember correctly Loctite softens at a little over 400 degrees.

 

[CurlyDave]

It looks like heat is your best answer.

If you are still nervous about it, go down to a welding supply shop and get a 400 or 450 degree "temperature crayon". Make a mark on the bolt head, and heat until the mark melts.