HELP with rear finish mower

[LHoyer]

I have a Kubota K348-7 rear finish mower that is missing the blades and the bolts that hold them on. I can get the blades with no problem. The problem is, Kubota doesn't have the bolts any longer. The only thing the parts list shows is a part number and the decscription as; bolt-LH thread. Anyone happen to know the size? I think this mower was probably originally made by Woods but I can't find a parts list under that number. Kubota's parts book shows this mower as a B348-7. If anyone has this mower and could remove a bolt and get me the size, I REALLY would appreciate it. I don't even know if this is metric or standard. Thanks everyone!

 

[bp fick]

If all else fails, there is always trial and error. Go to a good hardware, a really good hardware store and pick up a couple of bolts similar to that size, coarse, medium and fine thread. Save your receipt and take back what doesn't work. I know, it's hokey, but it is tried and true!!!! I am assuming you need good hardened bolts too!!!

You wouldn't be the first one to use this method.

 

[LHoyer]

Thanks but the problem is they are left hand threads and everyone (at least locally) doesn't stock. They are all special order.

 

[dodge man]

Any chance its a Brush Hog? They have manuals with pictures of the unit on the first page, and towards the back the list the fastners and torque spec. It might at least get you started on size and type of threads. Post a picture of it, it might help with the identy.

 

[638]

Can you give us an inside measurement of the bolt holes? The more accurate, the better. I have a chart that gives the root diameter of threaded bolts and may be able to help.

 

[luc]

I have a Kubota K348-7 rear finish mower that is missing the blades and the bolts that hold them on. I can get the blades with no problem. The problem is, Kubota doesn't have the bolts any longer. The only thing the parts list shows is a part number and the decscription as; bolt-LH thread. Anyone happen to know the size? I think this mower was probably originally made by Woods but I can't find a parts list under that number. Kubota's parts book shows this mower as a B348-7. If anyone has this mower and could remove a bolt and get me the size, I REALLY would appreciate it. I don't even know if this is metric or standard. Thanks everyone!

With Kubota part numbering system you can usually ( at least for metric) know what is the size and lenght of the bolt.
Look at the last 4 numbers after the dash,for example:
-51280 = 12mm, 80mm lengh
-91040 = 10mm, 40mm lengh
-50814 = 8mm, 14mm lengh

What I have not figured out yet is the pitch

 

[LHoyer]

Here is a picture. Will try to get inside measurements and post later.

 

[_RaT_]

You can get a pitch gauge, often times tap and die sets have them included. If its metric, you need a metric gauge. If you do not have local hardware stores with LH bolts, check a internet source. I would consider grade 8 bolts.

 

[LHoyer]

638-the part number is 70080-00121, so I don't think that helps.

luc-the best reading I can get is 3.00 to 3.06 mm

RaT-can't find my pitch gauge(standard), so will have tocheck around for one. Hate to order blindly as the bolts run in the vicinity of $8 to 12$ ea.

 

[aczlan]

638-the part number is 70080-00121, so I don't think that helps.

Messicks lists that as being a item they dont have in stock(Part Search) have you called them to see if they can get it in?

Aaron Z

 

[LHoyer]

I've tried a local dealer. Same as Messicks. Part is listed but not available. Thanks

 

[PHILIP8N]

Go online to McMaster.com. They have a large selection of left hand thread bolts. You will still be trail and error, but an educated guess on your end will narrow down the solution. Their bolts are much cheaper than $8 each, but you may have to buy a minumum quantity of 10. My finish mower takes two bolts per blade, as opposed to one bolt in the center. Dont know about yours, but is one solution drilling out the threads, installing grade 8 bolts, washers, and lock nuts? Philip.

 

[_RaT_]

I've tried a local dealer. Same as Messicks. Part is listed but not available. Thanks

You shold be able to look and see if its a course thread or fine thread. My guess would be fine. tape the diameter and see if you can find a standard LH and try it. 1/2"X 2" X LH would be my guess. If it starts but just won't thread past a couple of turns, you probably have a metric thread (unless you missed on course/standard pitch)

 

[leonz]

Is the gearbox tag in good enough condition to examine it and read it?.


I would hate to suggest the following but if you cannot find left ahnd threaded bolts for the unit you may be better off buying new arbors and bearing hubs for the mower as they are easy to obtain from many places.


You may just luck out and find everything you need at Agri Supply - Farm Supplies, Tools, Lawn Mower Blades, Cast Iron Cookware

1800-345-0169 they have lots of mower spares

saying that and making sure I did not brush my teeth with gun powder this morning-

1. as you know the threads are left handed;

a.be sure to wash out all the holes with WD-40 or alcohol to clean them.

b. use a new unsharpened pencil to determine the depth of the bolt hole-
dont hesistate to scrape around the bottom to dislodge any rust or cob
webs.
be sure to mark the depth on the pencil in the blind hole with a pencil or pen or scratch awl. where the pencil clears the arbor.

If it were me and was limited on tools and such I would find a machine shop bribe with ample donuts and coffee to ask for a minutes help as you are in a bind (if Agris upply cannot help you-but i would ring them up first.

Please understand that if you require a "compression washer" spring to
hold the bolt in place you will need to add length to the measurement of
the bolt and each time the blades come off you may need new washers-again agrisupply can probably be of help

these bolts are left hand thread to counter the G forces of the rotation
and in the process keeping the blades tight




c. are you sure you do not require a "compression washer" to gain more
pressure against the blade as is done with some mowers?

 

[LHoyer]

Thanks all for the various info. Decision is to drill and retap to something common. There is enough meat on the spindle and hopefully with lock washer, will be able to keep blades tight. This is not my main mower so it will only be used a couple times a year on about 1/2 acre.

 

[PHILIP8N]

General practice for tapping holes: material (if steel) to tap should be same thickness or greater than diameter of bolt (aluminum is 1.5 X). Example, If using 1/2" bolt, material (if steel) should be 1/2" thick or greater. I am sure you hub is steel or cast iron. If material is not thick enough, consider the lock nut option if you have clearance on the back side. Newer Woods mowers use two grade 8 bolts and lock nuts to secure the blades to the hubs. Philip.

 

[patdown45]

I have that mower and the thread is a 3/8-16 unc LH for left hand if you put some thread locker on the threads that should help from losing a blade I am looking for the knife holder and possibly the entire shaft assembly as one i have is bent and missing parts