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.