Metro 36-blade change difficult

[eball]

A homeowner with a metro bought new last fall with just 14 cuts on it and the same number of hours.

Need to change the blades. I can not believe how tight the blade nut is. Absolutely impossible to remove.

Any advice?

Thanks in advance

[TJLC]

My new Lazer Hp had the blades on really tight from the factory. I had to use my impact set at about 120psi to remove them. After that it was no problem. Good luck.

[Toroguy]

I would try some wd40 and a breaker bar, if that doesn't work put a hollow metal pipe over the breaker bar for added leverage.

Did you hit anything with the blades rotating?

[eXmark]

eball,

All are good advice. I ran a 32" Metro for the past several years and at times I would run into the same thing. The easiest and best thing to do is to invest in an electric impact gun or if you already have an air compressor get a pneumatic.

If neither of these are an option eat your Wheeties and get a socket, breaker bar and a large locking pliers.

Raise the front of the mower up and set it on a set of jack stands, lock the parking brake and block the rear tires. Clamp the pliers to the rear baffle so that when you try to remove the bolt or nut the pliers acts as a blade stop. This will usually allow you to gain enough leverage to "break" the bolt or nut loose. The place another wrench on the other end of the bolt and remove it. There are other ways but the best way is to invest in an electric or pneumatic impact gun.

Also when you put the blades back on, tighter is better. If you don't get them tight they will "self tighten" if you hit something or in thick lush spring grass.

If you have any other questions or you would like me to elaborate call me at 800-667-5296.

Thanks

Terry

[MetroBoy]

I just registered on LawnSite to ask the same question that eball has. I cannot get the blades loose from my 2001 36" Metro.

One thing I don't see mentioned here or in the Operator's Manual is the size of the bolt. It seems to be too large for my 7/8" and too small for 15/16"... too large for 22mm and too small for 23mm... I'm afraid to put too much torque on it for fear of rounding off the bolt head. What size is it??

[eXmark]

Metroboy,

The correct wrench is a 15/16". Be certain to use the box end and not the open end or use a socket and a breaker bar. I believe the blade bolts are a grade 8 so if you have the wrench on the head of the bolt properly it should handle as much torque as you can dish out.

The best thing to do is use an impact if this becomes too much of a problem.

Thanks

Terry

[MetroBoy]

Thanks, Terry. The 15/16" seemed to be the closest fit, but my wrench just didn't feel snug enough to really crank it. I'll pick up a good deep-well socket and a breaker bar and try that.

By the way, I'm a homeowner like eball, and I love my Metro. There are now two Metro 36's living in my little neighborhood of 32 homes. They are priced competitively with a lawn tractor, will go places I'd not dare take a LT (I have a steeply sloped lot) and will (I expect) last years longer.

[eball]

Metroboy,

Hope your having better luck then I. The breaker bar and penetrating oil haven't worked for me.

I've clamped the blade (wood blocks and vice grips) and had the bolt turning independent of the blade which made me believe I had it.

After a turn or two I realize that the spindle was turning. Insane yes, but true.

So blade stationary, and Bolt turns the spindle.

Appearantly, I've no choice but to round up an impact wrench. If the spindle turns as before I don't see how this will work.

I'll post my results if and when I get them.

[troberts]

I have a Metro 48 fixed deck, and also had trouble getting the blades off, and didn't want to invest in an impact wrench (no need other than the mower).

I've removed the blades probably four or five times now (install mulch kit, and height adjustments).

It took two guys. One on the top bolt, and one on the bottom one. We still coudn't do this by hand.

Here's what worked: Top bolt guy (15/16 box end wrench) holds top firm in place. Bottom guy (15/16 socket wrench) hammers on the wrench with a dead blow hammer until loose. Takes about ten wacks to get it loose enough. Be sure you're going the right way to loosen (use top bolt to determine the direction - counter clockwise)

Note: The bolts do "self tighten" under normal mowing conditions (I'm just a homeowner also), and will be just as difficult to remove the second, third, fourth... as the first.

It's really pritty simple once you get the hang of it. I adjust height in the spring and fall, so I do this twice a year. My father-in-law and I can remove all three (and replace) in about 10 to 15 minutes.

Good luck,

TMR

[Shadetree Ltd]

I have Turf Tracers, not a Metro but is there not a flat spot on the spindle for a 1" wrench? We used to struggle with the blades and I finally went and bought a 1" box wrench to hold the spindle while removing the 15/16" bolt and it works great now. I also make a point of putting some kind of removable lock-tite on the bolt everytime to.

Scott

[eXmark]

Hi guys,

All floating deck models at one time had two "flats" machined in the spindle shaft that would allow you to use a 1" wrench to hold the spindle in place while you removed the bolt. Due to design change a few years back the “flats” have been eliminated.

"Self-tightening 101"

All blade bolts have the potential to self tighten not only upon impact with something large and heavy but also under normal conditions if the grass is thick, lush, wet or heavy. The key is to reduce it as much as possible. I ran a Metro 32" for several years and had a problem the first year. After that for the most part I did not have too much difficulty. The machine did not change but my installation practices did.

First make sure you are putting the blades on TIGHT. With in reason the tighter the better. If the blade is not tight to begin with it will self tighten much more easily. Replace the spring disc washers as needed. In my case I replaced them once per year or when the washer lost it’s “cup” when removed. It was well worth it when I considered the number of times I threw my 15/16" wrench across the garage and the going rate for replacement windows, lights and other breakables. The other thing you want to do is make sure the head of the bolt, the face of the spindle and the blade where if contacts the spindle are all clean. No dirt, no water, no grass and especially no oil or anti-seize. This goes for the nut, washer and pulley on the topside as well. You want these surfaces clean so they grip. More grip means less slip and less slip means less self-tightening. None of these will eliminate self-tightening but all will help reduce it. Follow these guidelines and it should help:

Make sure the blades are tight
Make sure the mating surfaces are clean
Replace the spring disk washers annually or as needed

Let me know if you have any further questions.

Thanks

Terry

[MikeLT1Z28]

what i do when i change mine is get my torque wrench and use it on the top side (nut) and then i get another 1/2" drive ratchet and use it on the bottom. if you have a jack handle or something you can slip over the lower ratchet, you can brace it against the back tire and then back the nut off with the torque wrench. make sure to retorque them to 75-85 lb ft. also make sure you get your spacers back on correctly (not that i'd know anything about that, right Fred? lol).

[eXmark]

Guys,

Here are a couple of things that can help. When getting a socket or wrench for changing blades buy a 6-point socket or wrench NOT A 12 POINT. The 6 point will not round of the hex nearly as easily.

The other thing that helps is put your force on the nut, not the bolt. It's easier to turn the nut off the top than it is to twist the bolt though the spindle assembly.

The problem could be the bolt is slightly rusted in the spindle, if that’s the case you it will be very tough to turn that bolt. This is where a squirt of penetrating oil helps.

On these blade bolts that are stubborn block the bottom wrench or tool. Put all your twisting force on the top nut and it should help. After you get nut off you may have to drive the bolt out.

Mike is right put the washer back in order and proper torque of the nut is a must.

Thanks, Fred.

[lazer 46]

I just changed my blades on my 48 inch tthp for the first time. It took a breaker bar and an extension pipe to get them loose. I have two tthp's and they both have the flat spot for the 1inch wrench but the wrench does not fit that easily and it is a job to get it back off. I guess it is a tight fit so as not to slip off. I put anti sieze on the bolts and this always seems to work well through out the year. Also noticed that my owners manual says to torque to 120 pounds which is what my Lazer manual says. Is this correct. Always torqued 75-80 lbs. on Turf Tracer.

[eball]

Thanks everyone for your suggestions.


Two breaker bars did the trick. The one on top rotates nicely against the frame (use a wood block to avoid paint damage).

I notice significant stress corrosion on the bolt and the nut so I oiled it up and threaded on and off a bit to clean it up.

Now on to my next challenge of the best mulch blade type. I'll post this separately however.:blob3: :blob4: :blob1: :D :D

[MetroBoy]

Well, I think I tried about every suggestion on this thread. The local NAPA store loves to see me coming now. Tried a WD40-type penetrating oil, with a 24" breaker bar on top and a wrench on the bottom with a big pair of vise grips on the baffle blocking it, tapped the breaker bar with a mallet, tugged it, got lots of torque, but I couldn't keep the bottom wrench in place, and after a few tries, I could see the head of the bolt starting to round off.

I always was a lousy mechanic. I finally gave up on the low-tech methods and headed back to NAPA for an impact driver. I already have a compressor so I didn't have to spend a fortune. Three seconds and the first one was off. I think the second one was even faster. Great tool. Even somebody with a name like MetroBoy can remove the tightest bolts with ease.

Thanks all for the advice. This is a great forum.

Oh yeah, milk crates under the front casters work great too. Found that on another thread. Thanks, dlandscaping.

[eXmark]

lazer 46,

The torque on the floating decks is 120 ft.lbs. on the blade bolts and 75-80 ft.lbs on the top nut of the cutter housing.

Now for the ridged decks (Metro and Viking) since they have a thew bolt design, they hold the blade and the housing together with the one bolt. This torque will be 75-80 ft lbs.

Thanks, Fred.

[lazer 46]

Thanks for clearing up the torque issue. I didn't realize that the fixed decks have a different system of rmoving the blades. I've always had floating decks and was beginning to wonder if i was taking the blades off correctly. Further back in this thread you stated that the floating decks did away with the flat spot on the blade shaft for the 1" wrench, but I have a brand new Turf Tracer and like my other it has the flat spots on it. Just wondering. Thanks for the info and a great product.

[brucec32]

stuck bolts have been a problem on my lazer z hp. I even had to cut one off and drill it out to remove it after hitting (slightly) an object. They sometimes stick even w/o hitting anything. I finally switched the compression washers for flat ones and that has helped some. But I still have to trot out my impact wrench to remove a stubborn one from time to time. In 6 years of use on 3 Toro walk behinds, I never once had a stuck blade. The Exmark design could probably use a little modification. My lazer z hp doesn't have many flaws, but this is one.

[eXmark]

Bruce,

Replacing the spring disk or cup washers with flat washers should, at least in theory make the problem worse.

Some things that should help. Torque the bolts to 115 - 120 ft. lbs. If the blades are not tight they will self tighten very quickly and very tightly. When this occurs the momentum of the blade over tightens the bolt and it can become very difficult to remove. Another thing you can do is replace the spring disk washers a couple of times per year. These are in place to help ensure that the bolts don't over tighten if torqued properly. You should also make sure you don't have any oil or foreign matter on the surface of the blade or the spindle face where the different components mate to each other. Even a small amount of oil or anti-seize on these surfaces can allow them to over tighten.

An impact may be necessary for each blade removal even if you don't hit anything unusual depending upon what you’re cutting.

Thanks

Terry

[brucec32]

Hi Terry,

I have to say, since I went with the flat washers they've definitely been easier to get off. I have to use the impact wrench less often, for whatever reason. Your points make sense, but I still am curious why the Exmark design gets stuck and the Toro one didn't. I can't figure it out. In my experience, hitting the object seemed to compress the original washer to such an extreme degree that it was hard to overcome that friction. Brass flat washers do tighten up, but they can be removed with my impact wrench. I saved the compression washer I spent 2 hours getting freed with a dremel tool as a souvenier! Even my air impact wrench didn't do the trick that time.

[eXmark]

Bruce,

Thanks. I'll pass your comments about the flat washers along to our engineering staff.

As far as why the Exmark spindle tightens up more you need to look at the performance differences. How did the engines compare in a horsepower contest. The other consideration is blade tip speed. I'm quite confident that the same high blade tip speeds that allow our decks to cut better than some others also contributes to the self tightening of blades upon impact with debris in the lawn.

Thanks

Terry