PDA

View Full Version : Impact Wrench...Now What?


SteveInMD
05-14-2005, 10:56 AM
I thought my days of PITA blade changes were over. I went out and got a good quality impact wrench rated at 600 ft/lbs. I lifted up my Exmark and only got one blade off! :angry: After some PB Blaster lube I managed to get another off, but no luck on the third. I'm going to let the PB Blaster soak in a while.

My question is how do I keep the blades from seizing on there? The last guy to change the blades was the dealer. Maybe they over torqued them, but I've had trouble before. Is it safe to use anti-seize compound on the bolts? Is there anything else I can try?

cndhaines
05-14-2005, 11:20 AM
use anti seize on everything u want to actually take apart, blue lock tight if u want it to hold together like on engine bolts but still want to be able to take it apart , red lock tight if u never want it to come apart.



chris

GreenUtah
05-14-2005, 11:43 AM
antiseize is perfect for that application, keeping water off the grass from rusting the bolts inside. WD(water displacement)-40 also is decent on blades that come off weekly or sooner. I do want to mention, however, that you should make sure that you do not put your blades back on with your impact gun at it's highest setting, in case you hadn't considered that with the new tool. We always took off at max, put on at minimum and never had any trouble with loosening or anything of that nature.

DeWitt Lawncare
05-14-2005, 12:05 PM
Everytime my mowers are in the dealership, I can't get the blades off with my impact wrench. I took my mowers up to the tire place and they took them off for free. It's been my experience that a homeowner's impact wrench won't lock the nuts on too tight. I doubt you'll have a problem if you have a commercial guy take them off and you put them back on.

jimslawns
05-14-2005, 01:03 PM
Anti seize will help out, unless you clobber something with a blade and it torques down the blade on impact. Then, as much as I hate to say it.... Cheater bar if the impact wrench fails.

John Gamba
05-14-2005, 01:22 PM
Anti seize will help out, unless you clobber something with a blade and it torques down the blade on impact. Then, as much as I hate to say it.... Cheater bar if the impact wrench fails.

This is very true.
Also if this does not work you will have to heat up the bottom of the shaft where the bolt goes in. Do not over heat it or you will blow the seal. I have bent blades trying to take off the blade bolts on the spindles that the bolts where put on to lose and they tighten up on there own pretty good.

John

beransfixitinc
05-14-2005, 02:13 PM
Is it safe to use anti-seize compound on the bolts? Is there anything else I can try?

Make sure you do not use a copper or nickel based anti seize on the blade bolts. Try to find one that is a food grade compound.

I don't recall, but I think I read this in a Scag or Exmark owners manual.

TClawn
05-14-2005, 03:08 PM
I had the same problem. spent over two hours with a air ratchet, impact gun, breaker bar, everything. finally got them of, but is was a major pita. the bolts even had anti sieze on them.

TURF DOCTOR
05-14-2005, 03:12 PM
Anti-seize or spit on it, don't tighten them next time we pull blades off everyday

SteveInMD
05-14-2005, 03:25 PM
Make sure you do not use a copper or nickel based anti seize on the blade bolts. Try to find one that is a food grade compound.

I don't recall, but I think I read this in a Scag or Exmark owners manual.

BTW - I did manage to get the last blade off. I re-installed them with anti-seize on the threads, washers, and spindle bases. The anti-seize I used is made by Permatex, but it doesn't say if it has nickle or copper in it. Does anyone know who makes a food grade product? I checked my Exmark manual and I didn't see this above note, but then again my machine is kind of old, maybe it came out after mine was built.

captken
05-14-2005, 03:34 PM
Make sure you do not use a copper or nickel based anti seize on the blade bolts. Try to find one that is a food grade compound.

I don't recall, but I think I read this in a Scag or Exmark owners manual.

Now that does not make any scene. Editable Never~Seez? Formulated to FDA standards? [white formula] Grazing cows on that lawn after mowin'?lol :p

I have used Never~Seez Marine grade [got plenty] and have not had a problem. It only takes a small amount and you don't have to slather it on.

The reason to use it is because it protects against rust, seizure, and galling.

If you are using a impact wrench to take them off and on with no regard to the amount of torque you are applying, you have probably already damaged the threads on the bolt/bolts.


Start fresh, with new bolts, grade 8 or better, then apply the anti-seize of your choice, and go easy with the impact wrench from now on.

SteveInMD
05-14-2005, 04:03 PM
....and go easy with the impact wrench from now on.

I wish the Exmark dealer would take your advice. :)

Oldtimer
05-14-2005, 05:31 PM
If you will tighten the blades to about 115 - 120 pound feet of torque they will come of very easily. If you don't get them tight enough it may take 300 pound feet of torque to remove them.

Using anti-sieze is a waste of time. You will not find any manufacturer recommending anti-sieze on their blade bolts.

The new spindles coming from eXmark have addressed this problem and only require 55 - 60 pound feet of torque since they are using a blade driver in addition to a washer and bolt. The only difference on the blade is a .94" center hole because of the size of the star shaped blade driver.

nelbuts
05-14-2005, 07:31 PM
Tell your dealer DO NOT USE AIR GUN ON BLADES!

The only reason blades should be that tight is when you hit something.

I use a wrench and a socket to put on and take off all my blades.

If I hit something then I use a breaker bar and a very long pipe. They usually come off with that set up. If not I heat it up a little and off they come.

YardPro
05-14-2005, 07:49 PM
your impact is only as good as the air supply. you need a minimum of 1/2" line to feed it. also make sure your compressor has the psi and cfm to turn it...

we have the same problem sometimes... we have a smaller compressor.... i can take the same impact wrench down the street to a marina where i know the owner, and hook up to thier line and bam, the bolt comes offf without a problem.........

LawnMower
05-14-2005, 09:23 PM
My buddy is a foreign car mechanic and he swears by this stuff called, ( Wurth CU800) But it is a copper past.

YardPro
05-14-2005, 09:24 PM
The Copper Antiseize Is For High Temp Applications

siclmn
05-15-2005, 11:44 AM
Anti seize is only for high temp. All you need is any lubricant. Oil is good enough. You should not be leaving the blade on long enough for them to seize up. A impact wrench set at 600lbs??? Get a high quality wrench rated at 120lbs. It will do the job.

work4green
05-15-2005, 11:59 AM
What was the pressure on your compressor? 125? Many commercial compressors are set at 150 or 175, thats why it was tighter with the shops impact... It may be safe to bump yours up temporarily- if the manual says so only! Otherwise a looooong piece of pipe and a wrench should work. I use an impact all the time on my blades- the reverse setting has more torque than the on setting. Most decent impacts are built this way.

beransfixitinc
05-15-2005, 01:25 PM
Here is one of the ones that we use in the shop.

http://www.grainger.com/Grainger/productdetail.jsp?ItemId=1613540894

Seems like they've changed the specs on it.. I could have sworn when we bought it that it had 1000ftlb in reverse.

topsites
05-15-2005, 02:07 PM
If you are using a impact wrench to take them off and on with no regard to the amount of torque you are applying, you have probably already damaged the threads on the bolt/bolts.


Start fresh, with new bolts, grade 8 or better, then apply the anti-seize of your choice, and go easy with the impact wrench from now on.

Yeah you're not supposed to just hold the trigger, I impact mine every day and use the lowest torque setting (CP gun) and go real light, just pop-pop-pop and that's it. Technically it should be snug, you should be able to get them off with regular hand-tools afterwards. And if the dealer you're taking your wb does that crap where you can't get them off, stop taking it there.
Hate that crap, tire places used to do it all the time to my car, bent my brake rotors once or twice. Got to where I pull my own wheels off nowadays, bring them the wheels, they put the tires on and I pick them up later.

SteveInMD
05-15-2005, 03:13 PM
Here is one of the ones that we use in the shop.

http://www.grainger.com/Grainger/productdetail.jsp?ItemId=1613540894

Seems like they've changed the specs on it.. I could have sworn when we bought it that it had 1000ftlb in reverse.

That's exactly the one I just got.

hustlerdealer
05-15-2005, 04:16 PM
ol' timer is right. you really do not need never-seize. if the bolt has proper torque, it will not continue to tighten everytime you hit something. like antbeds, bricks, and water meter lids. the blade bolt getting tighter with each heavy object it hits. or hell, just use never-seize! payup

beransfixitinc
05-15-2005, 05:06 PM
That's exactly the one I just got.


Well, if it's not working for you, your air volume must not be high enough.

I know I was trying to use it the other day to quickly remove engines from junk mowers so they could be scrapped. This was out in the yard, and could not move the large 80gal compressor, so had to use the old BlackMax wheeled one and it would barely turn the bolts out because the old compressor could not supply enough air and the hose I had was not a big enough diameter.

Can hook it up to the one in the shop though, and it takes off anything.

I believe this compressor http://www.mytscstore.com/detail.asp?pcID=1&paID=1010&sonID=469&productID=9181&zz=76574&x=2&y=9 is the one we purchased.

N.H.BOY
05-15-2005, 05:10 PM
How does the Dewault battery 18v work??? Any one use it?

SteveInMD
05-15-2005, 06:31 PM
[QUOTE=beransfixitinc]Well, if it's not working for you, your air volume must not be high enough.
QUOTE]

The manual says to run it at 90 psi, which I've got. It must be that my hose is too small to deliver enough volume of air.

I've removed the blades and put antiseize on everything. I did the reinstall on the lowest setting, so I'll give it a few days and try removel on the high setting. I'll also get a bigger air hose.

Thanks.....

mosmgras
05-17-2005, 06:18 AM
I use an impact wrench to remove/replace my blades on a weekly basis during the season. I remove under full pressure and replace with 50-60 psi. With this setting my gun will torque the bolts to 120-140 ft./lbs. Seems to work well for me. To my knowledge most spindle bolts are fine threaded and don't require an extreme amount of torque to hold. Just my $.02

hustlerdealer
05-17-2005, 08:55 AM
here is a test for all to try. next time one of you guys gets your blade bolt stuck, break out the torch and cut the head off your blade bolt. when the blade falls off and you remove the rest of the bolt by hand, you will really see that you never did need the anti seize after all. you just needed to properly torque them to start with. i see this in my shop daily.

SteveInMD
05-17-2005, 09:13 AM
I agree the threads aren't seizing. To me it looked like the seizing was between the blade, washer, and underside of the bolt head. This is probably from the water getting in there while mowing. Grease would probably reduce the corrosion/seizing just as well as antiseize.

Runner
05-17-2005, 09:23 AM
How does the Dewault battery 18v work??? Any one use it?

I have the Makita 14.4, and it works great for this. I've been using it for years, so I know the DeWalt you're refering to would be an excellent choice.

captken
05-18-2005, 12:13 AM
Changing the blades at least everyday, then sometimes again during the day.
Day after day, week after week. Month after month. Bolt on, bolt off. That creates a lot of cycles.
Metal fatigue occurs when you overtighten a bolt. It will always exibit permanent elongation whether or you use a lubricant or not.
That being said,
Dry bolt on, dry bolt off. If you measure the distance the thread travels each time you take a bolt off and put the bolt back on, and tighten it, you would find that over a period of time, that the bolt has some mileage. The wear is in the form of adhesive friction, the threads sliding against threads and is called galling.

Galling occurs when this friction creates small tears in the metal where the dry threads rub against dry threads. [to draw the bolt in to tighten the blade, or when you draw the bolt out, to take off the blade.] Using an impact wrench to quickly torque on and to quickly remove dry bolts, creates friction, you can feel it in the form of heat [micro welding], if you care to examine one after you use an impact wrench.

This is why I like to use an anti-seize compound. Makes my job easier. No dry bolts for me.

Since using it, I haven't had to apply heat to get a bolt off much less cut the bolt with a torch.

BTW, when you cut the head off with a torch, you are heating up the bolt in the process...

Galling almost never occurs when you use it. Can change torque values, according to some. Definitely makes the blades easier to change.

This link will explain the physics, shock loads etc. 2 pages short. Scroll past the MSDS to the next page. www.jetlube.com/oilfield/MSDS/kkind.pdf