7800 broken axle bolt

   / 7800 broken axle bolt #1  

B7800mike

Member
Joined
Mar 5, 2008
Messages
33
Location
Farmington NH
Tractor
kubota b 7800 hsd
Hoping to get a little help here. I broke an axle bolt on my B 7800. The bolt was where the hoe sub frame bolts to the axle. Tried to drill out and ez out the bolt but it broke in side it:mad: I am going to try a harder drill bit and try again but wanted to know if any one had advise on pulling the side of the trans apart. I have the manual. any suggestions or tricks or warnings. The axle still has 3 out of 4 bolts and i have changed all other ones. hard to believe that a woods back hoe uses 8.8 bolts and not 10.9. :( Hope to have pics soon.
 
   / 7800 broken axle bolt #2  
I've got to ask this since i just installed a woods sub-frame / hoe on my 3030 this weekend. Did it break when you were tightening it, or from using the backhoe???

Unfortunately, i have no advice, other than what you are doing. Drill.... and easy-out.
 
   / 7800 broken axle bolt #3  
That broken easy-out is going to give you heck.

Sure you can't get it out ?
 
   / 7800 broken axle bolt
  • Thread Starter
#4  
The bolt broke while using the hoe and it is on the left side. Make sure the bolts you use are 10.9 not 8.8 like were installed on mine.
 
   / 7800 broken axle bolt #5  
once you're done make sure those bolts are high grade bolts and not previously replaced with something weak.

first step - throw away all your EZ outs and ignore anyone who says "oh they worked for me before".

i highly recommend avoiding E Z OUTS. look them up on the internet or ask anyone who's done significant work. for every 3 problems they help, they cause 2 worse problems (as you may be finding out very soon if that's an important bolt).

they absolutely suck, they shouldn't even be available. the problem is they work on "easy" stuff that people don't know how to work on. most people don't know much about removing stuck screws and bolts and EZ outs work for the really easy stuff. but they are not tools for the serious mechanic or equipment user.

any number of other options would work on those ones that EZ OUTS work on. if an EZ OUT works...something else will also work. just don't even buy one. an EZ out will never outperform all sorts of other methods/tools out there. avoid the Sears contraptions too...i forget what they're called but they look cool but are weak as well for this kind of stuff.

first two things with stuck/sheared bolts.

first - penetrating oil. WD40 does not count, do not use it here. Deep Creep, Liquid Wrench, PB Blaster are all good and available all over the place. Spray all of the bolt that's accessible (top and bottom if applicable). Spray it down a few days in a row if you're not pressed for time. knock the bolt with a hammer is appropriate or wire brush to get corrosion/flaking out of the way.

second - heat. heat is your friend. at the very least torch the thing hot and let it cool down. that expanding/contracting process may break or weaken the corrosive problem.

when you actually go to remove the bolt heat is good. you want the outermost threads to expand (get hot) and the inner most to stay cool (smaller). this helps immensely. if you're removing a bolt....you want to heat the area all around the bolt (expand it) and keep the bolt cool. do not heat the bolt (or what's left of it!!!). heat for 30 seconds to 1 minute depending on area, size of bolt, and what kind of torch yo'ure using. you want to start trying to remove the bolt when the outer part is hot but the heat hasn't sunk into the actual bolt yet...because that will of course expand the bolt too.

the best thing for removing a stuck bolt is a left-handed drill bit. get the hardest/highest quality set of drill bits you can afford/wait to order in. they are life savers and worth every penny. after heating and penetrating oil they should get out almost anything. start drilling the bolt out. eventually the left-handed bit should grab and back the bolt out. if not..just keep drilling until the bolt is gone and retap/repair the threads.

that's the three keys for stuck/sheared bolts:
penetrant
heat
quality left handed bits
 
 
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