Sheared mystery bolts L175

[Beagledogxxx]

Anyone have an idea as to how these two bolts below my L175 pto could have been sheared off and/or how critical it is that I replace them immediately? It was like this when I bought the tractor but I didn't notice until a week later. Thanks

 

[Orange Tractors]

Unfortunately, I get the red X instead of a picture; but speaking generally, I would replace the bolts ASAP.

Robert

 

[Stumpy]

Agreed though those look like a bear to drill out. I'll try and look at mine and discern their purpose tomorrow before I head in and let you know.

Robert it's two bolts back on the rear axle casting just below and behind the protruding PTO shaft seal housing. They look like 8mm bolts snapped off a 1/4" below the surface from the picture.

 

[skeets]

Man those look like candidates for a left handed drill and easy outs

 

[Stubbyie]

Please advise what you determine these bolts to there for and how you proceed.

Soak in Kroil before doing anything.

Try applying hot iron repeatedly in hot-cool-hot-cool cycles to break rust bond.

If you try LH drills they can be hard to find. Try Wholesale Tool online and NAPA in a national advertisement stated they had started (once again) carrying LH bits individually in stock.

Center punch and start small and go slow.

Recent discussion in this forum between myself and experienced machinist-level machinery repair tech indicated about a 50% success using drills and eze-outs.

Good luck. Please advise.

 

[Beagledogxxx]

Thanks for all the advice. I'll pick up some l-handed bits and be sure to report back.

 

[skeets]

Oh yeah GO SLOW,,,, don't ask

 

[Big Kahuna]

I have been a Toolmaker for 29 years, I would not use a left handed drill bit, center punch a mark as close to center as you can and start out with a 5/32 drill bit and carefully drill into the rusted bolt, try and use an easy out that would use a 1/4 hole, you dont want go to big, leave enough meat of the old bolt so you have something to grip on, I find the straight tapered easy out work the best, that spirals put too much pressure outward.


My 2 cents..............Big Kahuna

 

[Stumpy]

I'll second Big Kahuna's method (that and drilling them out are about the only things that have worked for me) and suggest you do it in addition to the heat and the soaking in penetrating oil Stubbyie mentioned.

If you can't get it to budge then you'll have to drill it out. It's best if you know what the thread is when drilling it out. They look like 8mmx1.25 to me but remove one of the others and compare at a hardware store to be sure unless you've got a caliper or a pitch gauge at home. Once you know the thread look up the min Minor Diameter for internal threading here and cross reference to the next smallest inch drill and use that to drill out the remains of the bolt. You may even want to go one size smaller than what you come up with to prevent from digging into the threads. Once it's drilled out break up the remains with a drift and hammer and clean the threads up with a tap. That's plan B.

I looked at my machine and those holes still have the factory plugs in them and I know my machine had a Woods belly mower on it at some point in it's life. I'm not sure what that bracket is for on your's but it's always a good idea to replace broken bolts.

 

[Orange Tractors]

Anyone have an idea as to how these two bolts below my L175 pto could have been sheared off and/or how critical it is that I replace them immediately? It was like this when I bought the tractor but I didn't notice until a week later. Thanks

The picture actually opened tonight, I really dislike 26400 bps dial-up.

Agreed though those look like a bear to drill out. I'll try and look at mine and discern their purpose tomorrow before I head in and let you know.

Robert it's two bolts back on the rear axle casting just below and behind the protruding PTO shaft seal housing. They look like 8mm bolts snapped off a 1/4" below the surface from the picture.

Thaks for the description, Matt.

I went out and looked at my tractor, to get a first hand view. Why is it always dark when I need to look at a tractor?

Turns out mine is buried under the big drive pulley for the Woods mower, thus it is hard to see the bolt holes.

There are no bolts in those holes in my tractor, or the two that are above them. A small custom made probing device (read: stick) didn't go in more than 3/8" after I cleaned the dry grass and dirt off.

They appear to be a mountuing holes for a larger bearing for the PTO shaft. Maybe Kubota used this same housing for one of the larger tractors????

Based on my tractor, I am changing my recommendation to: Leave it alone, unless something is leaking from the holes.

Robert

 

[Big Kahuna]

Good idea ! I drilled the holes on the underside of the rear-end for the hitch mounting holes had stripped out ( to put thread inserts in ), you know how fast 4 1/2 gallons of Hytrans drains..............FAST.

Big Kahuna

 

[Beagledogxxx]

I'm pretty good at doing nothing at all so I'll take that advice. They don't look too critical to me, but I just wanted to make sure. Thanks for all the great advice once again. You guys make owning a 30-40 year old tractor a whole lot easier. Dave

 

[Lil Foot]

Reminds me of an incident in a machine shop I worked in years ago. We had a machine analyst (or anal list, as we referred to him) who diagnosed maintenance problems & set priorities for the millwrights who repaired the machines. While looking over an old horizontal mill, he spotted a set of four sheared off bolts that looked a lot like the subject bolts pictured above. He thought this would be a good job for our two rookie millwrights, and set them to work. They spent two full days drilling, hammering, heating, breaking easy-outs, cussing, and got no where. Finally one of them noticed that the threads appeared to be left-handed, so they tried the other direction, and all 4 bolts easily spun into the machine & dropped out of sight. Turns out they held part of the transmission to the crankcase from the inside! It took a more experienced millwright about a week to put the machine back together.

I agree, unless it's causing an obvious problem, I wouldn't open that can of worms.