RC40-G mower deck - weird center bolt head

[BruceP]

I have a G5200 garden tractor which I purchased this summer. I pulled the mower deck off for the winter to have some holes welded.

The the bolt which holds the center blade on has a very weird head pattern... kind of like a normal bolt.... but two of the 'flats' are longer than the other four.

Obviously, no 'normal' socket will fit over this bolt. Fortunately, I was able to use a large adjustable wrench on the two long 'flats' and get it off. I am not sure how I can accurately re-torque it without a socket that fits it.

I tried to research Kubota mower-decks with no mention of the weird center bolt head. I did find bolt P/N to be 70722-34370. I also noted that the center bolt has been superceeded by 70722-34374 (which does NOT appear to have the weird head on it)

However, I have not found any reference to what kind of special tool I need to fit the head of this bolt.

Does anyone here on OTT have any details about this weird head on the center blade bolt and what kind of tool to use on it?

I guess I could purchase the 70722-34374.... but it seems silly to spend over $10 for a special bolt when the old bolt is still serviceable.

 

[D2Cat]

Probably someone improvised. You could take the bole with irregular head to a good hardware store and maybe find a metric grade 8 bolt to replace it with.

Take your old bolt in and find a nut that hand threads onto it. Then find a new bolt that fits that nut.

 

[cviola2005]

Does the bolt appear factory machined or does it appear like it has been modified? Someone may have ground down the two sides that are longer to utilize the same wrench on all the bolts. just a thought....

 

[Delmar]

I agree that someone probably "improvised." Not sure, though, you can replace the bolt with one from the hardware store. If it's just a straight bolt, no problem. However, if it has a shoulder that nests in the blade or washers a regular bolt might not work.

 

[BruceP]

I agree that someone probably "improvised." Not sure, though, you can replace the bolt with one from the hardware store. If it's just a straight bolt, no problem. However, if it has a shoulder that nests in the blade or washers a regular bolt might not work.

Thanks to all for your words of wisdom.

The bolt I removed sure appears to be factory. It is a "shoulder bolt" which compresses a Belleville washer against the blade.

In my research of Belleville washers, they must be compressed to a specific pressure to perform their task of holding the load. I am sure that is what the shoulder on the bolt does.

I guess the bottom line is that NOONE has ever seen nor heard of Kubota using a mower center-bolt with an oddball head on it. I may have to spend $10 for factory Kubota replacement bolt that has a 'normal' hex head on it.

The scary part is that the factory Kubota Belleville washer costs about $30!!!!!! (Most Belleville washers cost less than $2)

 

[Delmar]

Can you post a picture of the bolt and washer? Someone on this forum might be able to save you some money. I know I've got a few extras I've collected over the years.

 

[CountryBumkin]

If you go to Kubota Parts http://www.kubota.com/part/partsList.aspx
you can lookup the part numbers for your mower.

For the RC-40-G (G5200) the numbers are:
Spindle 1 (Left side) Bolt, 70722-34370 >> replaced with 70722-34350 $9.09
Spindle 1 Retainer, Blade 70722-34350 $15.61

Spindle 2 Bolt, 70722-34360 (s/n <32185) and 70713-34363 (s/n >32186) however both of these are replaced with 70713-34364 $20.52


Messicks http://www.messicks.com/part/70713-34364/blade-bolt is where I got the prices.

They have pictures of the bolts. Neither both shows any odd head configuration (at least for the replacement bolts). Maybe the odd one you have is the original/old part number.

 

[BruceP]

If you go to Kubota Parts http://www.kubota.com/part/partsList.aspx
you can lookup the part numbers for your mower.

For the RC-40-G (G5200) the numbers are:
Spindle 1 (Left side) Bolt, 70722-34370 >> replaced with 70722-34350 $9.09
Spindle 1 Retainer, Blade 70722-34350 $15.61

Spindle 2 Bolt, 70722-34360 (s/n <32185) and 70713-34363 (s/n >32186) however both of these are replaced with 70713-34364 $20.52


Messicks http://www.messicks.com/part/70713-34364/blade-bolt is where I got the prices.

They have pictures of the bolts. Neither both shows any odd head configuration (at least for the replacement bolts). Maybe the odd one you have is the original/old part number.

Thanks for the pointers to the online parts.

As I mentioned in my original post, I have spent several hours with the online Kabota parts. They call the center "spindle 1" and see that the superseded bolt is has normal hex head.

I will try to get a photo of the bolt when I get a chance. (mower is stored 40 miles from my current location. Being prepped for welding)

 

[bucktail]

One of my neighbors contracts with Bondhus in Monticello, MN. I've seen him making wrench sets for bolts/nuts as you describe, but smaller versions of them. It's basically a socket pressed onto an allen wrench.

 

[BruceP]

Re: RC48-G mower deck - weird center bolt head

I finally was able to access the mower-deck to grab the center-bolt.

Now that I have cleaned the grunge from it and inspected, It is obvious that someone in the past must have 'modified' the bolt-head. The washer which was beneath the bolt clearly shows scars from the edge of a cutting-wheel.

I have attached some photos to show what I am talking about.

This bolt is VERY special with a double-shoulder to compress two belleville washers against the blade so I have to source replacement from Kubota.

I do not want to be messing with the design which allows for the center-blade to slip if it hits something. After-all, this center blade is driven DIRECTLY from the right-angle gearbox and has no other means of 'safety'.

The outer two blades are belt-driven and do not use this special type of bolt. They are essentially lock-washered against the blade.

Hopefully the two photos are viewable.

 

[kubotasam]

Find a large nut that is close to the size of the bolt head and weld them together. That is how I solved a similar problem.

 

[CountryBumkin]

But welding on the bolt changes its tensile strength.

 

[BruceP]

I stopped at the local Kubota parts supplier today expecting to order the new bolt and washer... I was surprised when the counter-guy said these are IN STOCK and asked me how many I needed.

I then asked if they have any Kubota keychains 'cuz my used 'bota came with just a bare key.... He handed me several and said they were complementary. I found them on eBay 3 for $60 ( http://www.ebay.com/itm/like/251364090075?lpid=82&chn=ps&ul_noapp=true )

So far, my experience with the local Kubota parts supplier is positive.

 

[Bulldog]

A good dealer means everything. Glad you had a easy fix.

 

[skeets]

60 bucks for 3 key rings??? Somebody is smoking so real nasty stuff, so is anybody buying them,,just MHO you understand

 

[D2Cat]

Sometimes on Ebay there are extremely high prices on items. For the sellers, somehow it saves their listing spot, when the item is out of stock. They just simply put such a price on it no one would buy.

That was my experience. I emailed the seller and told them how ridiculous their price was. That was their explanation. Out of stock.

 

[RCW]

So far, my experience with the local Kubota parts supplier is positive.

Bruce - I have found most stuff is the same or similar to Messick's or Coleman at my local place, and it's on my way to/from work. Of course - no shipping $$. I think SUDT2 is less locally.

I did stop last weekend and bought a "gasket" for the engine oil drain plug. Just a small rubber washer.....$7.15!!

Told the owner they (Kubota) must be pretty proud of those!

Not sure my tractor ever had one, so wanted to have one to see if I could get something similar.

Did see the $7.15 price online somewhere, but also saw $2 or so.