Stripped bolts on underbelly attachments?

[JerryC999]

On the left side of my B7100, where underbelly attachments would bolt to the tractor, two of three bolts seem stripped in such a way that I can neither remove them or tighten them. They are a different sort of bolt, however. They just spin in place right now, and I can't get either the nut nor the bolt threads to engage. On the right side, two of the three have been replaced with regular bolts.

What to do? Cut them and replace? How are they supposed to work?

 

[Jim L.]

Your picture shows studs. They either backed out and the threads got hit by vibration, or got overtightened and stripped the threads.

Since they are turning, I would cut or grind on the bottom side. They should then push up and out. If the plate is OK then run a tap or thread chaser in the hole to clear the threads. If the plate has been de-threaded, then you use a bolt-lock washer-nut combination to replace.

If you don't want to take the time to go through the nuts you can use a nut cracker tool to bust the nuts off. If you don't have one then saw or grind away, the time saved isn't worth a trip into town.

If the stud is locked in the hole, then you will drill it starting with a 1/8 bit in the center and increase bit sizes until you can get a bolt extractor into the hole. Still will need penetrating oil and possibly heat to loosen it. If you break the bolt extractor it is extra work. If it doesn't turn easily let it soak more penetrant oil or put heat around the stud area.

You might get lucky and be able to grab the top of the stud with a vise-grip and back it out, also.

If it were me, I would not use studs again. I would use bolts because it may strip again.

Someone else may have more specific experience.

 

[Bulldog]

Adding to what Jim said, if you have to drill might look at left hand drill bits. Lots of time just the drilling will get the stud out and if not then you still have it ready for a extractor.

 

[Diydave]

On the studs that you have arrows on, I would take a cold chisel, and a BFH, and split the nuts off, then put a pair of vice grips on the stud, and try unscrewing, while pulling outward on the vice grips. You also want to relieve the weight that may be on that bracket, by putting a jack under it. Once they are out, I'd just as soon replace them with a grade 5 or 8 bolt, and a nylon locknut. Add a lockwasher, if you wear a belt, and suspenders...

 

[JerryC999]

Man, O man, none of that sounds fun. The conclusion is - the studs are no good, get them out, and replace with a bolt.

Ok, this is stuff for big hammers and sharp implements - I will give it a shot.

Thanks all.

 

[Orange Turbo]

The nut on the stud that looks like it's still tight! Start taking it loose and see if the weight of the bracket will help pull it down putting pressure on the threads. than you might get into some thread that will allow you to finish taking them out. You can try putting a reg screw driver between the bracket and tractor to keep pressure on the bracket as you try to get them out. Than if you can get around the bracket, (once its down) they will be easer to work with.
Can you get bolts back in it?
If so, clean old threads out with a reg drill bit 1-size larger and go with a larger bolt.. Or re tap to the next size larger.

 

[JerryC999]

Ok, ended up bringing it to the neighbor, who is handy with all things. He got them out, but I also ended up with a weld on the piece. So, must have been a mighty struggle.

Good to go now! Now to get that belly mower back on and ready for the season. Thank you all for your input.