Sharpened blades on mower deck

[Petrol and Powder]

So I did some mowing today with the mid mount mower. When I was done there was still some daylight and I decided to sharpen the blades. Purchased the tractor and mower last Spring and this was the first time I did any maintenance on the deck.

HOLY COW those bolts are tight !

3/4" drive 18" breaker bar with about a 4' section of 1" pipe on the breaker bar just to get those puppies loose. The Impact wrench wouldn't even begin to break them loose.

When I was done sharpening the blades I put them back on with just the breaker bar. I put a little anti-seize grease on the threads before re-installing the bolts.

Anyone else have this problem?

Also, could only find 4 zerk fittings ; one for the idler pulley pivot, one on each U-joint for the drive shaft and one for the splined center section of the drive shaft. Is that all?

 

[Oldoak]

Those bolts were certainly put on way too tight. No way should it have taken that much force to break them lose. It would appear someone used an impact wrench to tighten them with any regards to the torque setting.

I don't have a Mahindra, but my JD X758 mower deck only calls for 50 Ft pounds of torque on the mower deck blade bolts. I just tighten them like you did, with a standard breaker bar and call it good. Never had a problem. I also use just a little Never-Seize on the bolt threads.

 

[KennyG]

Was this a new deck? I have found that factory assembly often overtightens stuff. Oil Filters, drain plugs, anything mounted to the frame, etc. Causes a lot of frustration.

 

[Petrol and Powder]

Yep, first time I had removed the blades. I understand the factory wanting those bolts to be tight but it was excessive. When I couldn't break them loose with an impact wrench or just an 18" breaker bar I grabbed a section of aluminum tubing that was handy and slipped it over the breaker bar. I snapped that tubing in about 1/2 second! I got serious after that and found a 4' section of steel pipe to use as a cheater and even that required more force than I anticipated.

Once they broke loose the bolts came right out. No rust, clean threads, no problems. Those bolts have fat cross sections and fine threads, so they're pretty strong but I don't think they need to be tightened to 500 + ft/lbs.

 

[Oldtink]

Right. The 24" blades on my 72" JD deck calls for 90 ft/Lbs, to give you an feel for it.
Maybe they had some kind of thread locker compound on the threads.

 

[JerryK]

While in a perfect world, everything would be tightened ' perfectly '. A little too tight is better than a little loose. Especially if they can loosen, fall out, and drain fluid out. Or in the case of a mower blade, fly off into the sunset. Some blade bolts tighten themselves if you hit something with the blade. And, in my years of changing diesel filters, I think they tighten themselves when they age... just out of spite...

 

[Navasot]

Why not just change the blades while your going through the trouble? Once the lift on the blade is warn down they can be sharp as possible but still not cut... or did you have a lot of rock dinks and whatnot in them?

 

[4570Man]

I've found for commercial mowing I have to change the blades about twice a year and sharpen them every couple weeks. Once the square edge of the cutting edge gets rounded over the cut quality suffers. I've never had the lift edge wear out. On my equipment I install and remove blades with my medium sized cordless impact. On newly acquired used equipment my bigger impacts or cheater bars are required.

 

[JK22]

I've read elsewhere in OTT that the WSM for Kubota decks seem to recommend 450lbs/ft for most of the MMM decks. My 1/2" Dewalt pneumatic impact will do 650ft/lbs. I haven't found a 3/8" that will go above 350. If possible, I think I'll be blocking my blades with 2x4 and leaving mine on to sharpen. Just seems nearly impossible to get the torque right otherwise.

 

[Navasot]

Yall actually check the lb specs on the mower blade? lol

Have put them on with wrenches and also with impacts and not had an issue