Trouble Changing BushHog Blades

[HarleyBob]

I purchased new Bush Hog blades for my SQ600 Bushhog
rotary mower. I have removed the blade bolt nuts and lock washer from above
but cannot figure out how to get the bolts out of the blade hodler assembly. Is the blade bolt driven out from above? They seem pretty set in their ways.
Is the bolt pressed in or threaded into the blade holder assembly?
The bottom end of the bolt is round, not hex etc that would allow it to be unscrewed.
Thanks. /forums/images/graemlins/confused.gif

 

[Bird]

Have you tried getting a hold of the end of the blade and wiggling it around. They've always just fallen right out for me.

 

[HarleyBob]

Bird, Do you mean pulling down on it or just rotating it. It moves around easily and has a little bit of wobble. I have been told that
the bolt may have a keyway in it where it goes throught the holder.

 

[geneP]

Yeah, they typically have a key on the shaft that fits through the blade holder. It's probably just choked up with grass and rust. Some penetrant or oil around the bolt will help, then wiggle the end of the blade up and down, as Bird suggested, and it should loosen and fall out. The most effort it should take is to tap the threaded end of the bolt with a drift pin and hammer to knock it loose. Just hit the center of the bolt, not the threaded portion.

 

[HarleyBob]

I have been hitting it quite hard with a rod and small sledge and it is not budging. I may drop the entire blade holder and try it on the bench with some heat. That is, if the blade holder (stump jumper) is not similarly stuck. This is the first time to try and remove blades after three years of use.
I will use some anti-seeze when re-assembling.

 

[Bird]

Sounds to me as if a little corrosion has caused them to stick. Maybe a little PB Blaster, Liquid Wrench, or even WD-40 would do it, and of course, as you suggested, a little heat might work.

 

[geneP]

Some of the gear boxes have keyed and tapered output shaft so that the stump jumper won't tend to get loose as easily as a straight shaft will. If it's mounted on a tapered shaft and torqued tightly it WILL be a bugger to remove.

 

[HarleyBob]

I got the stump jumper off so I can clamp it all to my bench.
When you apply heat to loosen bolts, do you heat the nut or the bolt or both? Are you heating things so they expand and then shrink and thus loosening things up, or do you want to try and
put the wrench on it while it is still hot?
Thanks

 

[Bird]

Ideally, when trying to separate two metal objects, you would heat the outer one to get it to expand and then try to cool the inner (bolt in this case) part to get it to shrink. Of course it's frequently difficult, if not impossible, to heat one without heating the other. And yes, I've put the wrench to them while they were still hot. Personally, I'd probably heat it pretty good, then spray a little WD-40 on the bolt to both cool and lubricate it, and then try to get it out.

 

[RickB]

They come off overly hard the first time lately. I remove the nut and lock washer, then replace the nut so the top of the nut is flush with the top of the bolt. This protects the bolt and threads. Then drive the bolt down with a large pin and hammer(sledge) until the nut is flush with the bar. Remove the nut and drive the bolt out the rest of the way. Clean up the bolt shank and the bore in the blade holder before reassembly; coat threads and shank with Never-Sieze compound or grease. Very rarely do I have to resort to heat.

 

[Theowegian]

I have a SQ600 BUSH SQUEELER rotary cutter, too. I tried to take the blades off last year and sharpen them. My bolts were stuck in the holders, too. I could not get the bolts out either!!!

I just gave up and put the nuts back on. I think the torque was 600 ft-lbs.

Please, let us know what you had to do to get them off, I want to do what ever you do....

thanks, dwight

 

[HarleyBob]

I got them off and here is how I did it. I took off the stump jumper/blade holder by removing nut underneath and then driving
the piece out from the access hole above the deck (it was hard, but not as hard as the blade holder bolts. I put the
blade holders on my bench and could not budge them with a 3 foot
cheater and light heat (my propane torch) I had to take the whole unit to a local metal shop who used major heat from a big torch and a large impact wrench to remove nuts. Then he had to use a hydaulic press to get the bolts out. I would never have
been able to remove them without the pro equipment.
I will re-assemble with anti-seeze and change blades more often
to keep things loose.
Thanks for all the help everyone. /forums/images/graemlins/wink.gif

 

[HarleyBob]

I got them off and here is how I did it. I took off the stump jumper/blade holder by removing nut underneath and then driving
the piece out from the access hole above the deck (it was hard, but not as hard as the blade holder bolts. I put the
blade holders on my bench and could not budge them with a 3 foot
cheater and light heat (my propane torch) I had to take the whole unit to a local metal shop who used major heat from a big torch and a large impact wrench to remove nuts. Then he had to use a hydaulic press to get the bolts out. I would never have
been able to remove them without the pro equipment.
I will re-assemble with anti-seeze and change blades more often
to keep things loose.
Thanks for all the help everyone. /forums/images/graemlins/smirk.gif

 

[JimME]

Just bought and changed the blades on my Bush Hog 286 (72") today.

I too got the nuts and lock washers off (with a 3/4" drive and a sledge hammer), but couldn't get the bolts out for the life of me.

I called the Bush Hog company today and talked to a guy in the service department and told him of my troubles. He chuckled and told me that the bolts are pressed in and have a key way. He said heating won't do much good. He then told me the "secret" to removing the blade bolts.

He said to raise the bush hog, turn the stump jumper so the bolt is visible through the access hole and then place a big block of wood under the stump jumper right next to the blade to be removed and then lower the bush hog back down to the ground. The block of wood needs to be supporting weight and this keeps everything from flexing as you pound on the bolt from above. I got a piece of 1" brass rod stock (so I didn't scarf up the threads) and a hand held sledge and after a dozen or so whacks I felt the bolt loosen and then rocket to the ground. Yehaw! This was most welcome and made me quite happy. I then turned the stumpjumper to do the other bolt and removed it as well. I did find that the block should be right next to the blade but cannot be supporting the blade.

So there you go. The "secret" to removing bush hog blade bolts at home from the Bush Hog service department.

 

[dknarnd]

Well if I ever get the nuts off at least will know how to get the bolts out! I have a 15" adjustable on the tool to remove the nut then a 3' pipe on the end of the wrench and still can not budge the nut. This unit is about 12 years old and has never had the blades changed.

Actually it is in bad shape, needs a new pto shield, and where the blades spin the deck has tore open and needs to be patched and welded plus the rear needs to be welded again on both sides, so I may just buy another one for next season. I'll keep the old one strip the pto gear box and blades off of it and make a little 3pt gear carrier and counterweight.

 

[Phred]

Get an impact.

I use an IR thunder gun with sears 3/4" drive sockets.
Hit it with a little PB blaster and then let it sit overnight.
It will then come off with an impact gun easily.

I found that I can just beat the bolts out with a hammer.
Takes some arm strength, but they will come out.

Getting them back on without an impact will also be non-trival.
The new bolts on my machine are a tight fit into the key way.

Fred

 

[ScottAR]

I use an actual "bush hog blade" socket that dad kept from the family farm. It's from the 50's and I dunno where you'd find another. The bolts are still the same size though!

What makes it different than a standard socket is instead of a square hole it has a 2" piece of solid square stock about 8" tall cast on to the back.

Attach a just as old 24" pipe wrench onto the square stock and hit the handle with an 18lb. sledge. They come right off. /forums/images/graemlins/crazy.gif
Then take a 1" round drift, hold with 12" slip joint pliers, and hit with above sledge.

Putting them back in is just a matter of starting them in place with a 4lb. hammer and finishing with the 18lb. hammer.

Easy! /forums/images/graemlins/grin.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/tongue.gif /forums/images/graemlins/wink.gif

 

[RickB]

That special 1 11/16" socket is still available from Bush Hog at around $30 last I knew. It and a 24" pipewrench and perhaps a cheater are what I routinely use to remove the blade bolt hardware when doing road service. To remove stubborn bolts, I remove the lock washer, replace the nut flush with the top of the bolt, place another nut on top, set the Bush Hog tool over both nuts and strike the top of the tool with a 12lb sledge. One or two shots usually dislodges the nut without fear of thread damage.

 

[Travis_R]

I just took my SQ600 blades off for the first time. I will have them beat out. I do EXACTLY what RickB said in his first post. Nothing different.

My buddy has a SQ720. He said that his first time to take the blades off was very hard. Harder than mine. But he eventually got it.

Sounds like some are harder to get off than others. I guess it depends on how long they have been on there.

Travis

 

[slowzuki]

Just a followup to this, I'm fighting with an SQ600 too, we supported the blade holder and have been pounding with an 20 lb sledge to drive the bolts out with no success. We also have been trying to get the blade holder off with no luck.

Nuts came off ok with 6 ft cheater on the 3/4 drive sockets.

We'll kept trying. Two of use are 4 hours in so far. I pulled a 25 year old bushhog brand one apart a last year and it wasn't this hard. Probably had been apart a few times in its life.