The gear box has come loose a couple of times through the years. I have to take the stumpjumper off to tighten the nuts. The nuts are the nyloc type, but still get lose over time.

My question is, why can’t I weld the nuts to the bottom of the 10” channel iron the gear box is bolted to? I can cut them off if I ever had to. I can tighten the bolts from the top if I weld the nuts.

Thank you for your replies.

Does the gearbox tighten down directly to the piece of metal we are looking at?

I know that sounds like a dumb question but I had that same problem with ours back when I was a kid. There was two pieces of metal with about 2 inches of gap between them.

It was a piss poor design that you never could keep it tight. When it cracked all to hell we cut some pipe and welded in there and fixed it.

Carry on

Not enough threads/room to double nut it using a slightly longer bolt?

Get rid of the nylocs and use some good old fashened lock washers and regular nuts.

Have you tried putting on new nylon nuts? They only work really well the first time around.

Guess you could do that. You could also weld a couple of “nubs” next to each nut, so the nuts wouldn’t spin, and you could tighten from the top.

If clearance allowed (and it may not), you could also weld the nuts to two separate pieces of 1/8” steel “strap” (that had been drilled)so that each “strap” had the nuts for two of the bolts, and then they wouldn’t spin when tightened from above, and you wouldn’t have to weld to the deck. Would require a slightly longer bolt, though..

Red loctite and a big breaker bar to tighten them down

This...or weld the nuts.

I used to have a bush hog that vibrated something loose pretty regularly. I think the plate the blades attach to got bent and caused the vibration. I have a different bush hog now and have not had that problem.

Red lock tite.

Nut and lock washer

Or new nylock

Or do what i do sometimes...


Cross thread the [bleep]

Yes. That is bottom of 10” channel iron.

It would probably work. But I'd try some aircraft nuts. They're similar to the nylon lock nuts except the steel is crimped at the top of the nut to lock them in place. It takes some torque to affix them. But they don't come loose without some serious stress.

https://www.earnestmachine.com/sites/default/files/products/imported/NAM.pdf

This and new bolts if possible, all grade 8.

All the recommends would probably help, but the real trick is enough torque. Put the biggest frickkin’ impact gun you can find on them, they call for around 450 ft lbs if I remember right. I put new bolts, lock washers, and nylock nuts on mine then bore down on it with a big electric impact gun, that’s what it took to finally get them to stop coming loose.

Get some regular nuts or steel lock nuts and put some red locktite on it.

One was driving me nuts with loosening - I welded the bolts to the pan with threads going up and could observe and tighten nuts from the top.

Red lock tight is insane. My Milwaukee impact gun has a hard time loosening it up

THIS.

Weld it. There's very few mechanical questions that that's not the answer too. I've seen stuff you've made, weld it.

Make sure your PTO shaft is balanced and all u-joints are square, tight and well greased, make sure your blades are [balanced] of equal weight, ny-lock nuts and lock washers are junk, grade 8 fine [machine] thread bolts with flat washers and actual crimped steel lock nuts, red Loctite it all together with short cheater or break over bar, you can heat Loctite with torch if need to remove later.

Yep.
This would cure the problem.

Or do like jackmountain said, red Loctite, brad the hell out of the shank, then weld the circumference!

If the holes in gear box or channel are "wallered" out much at all you have hard time keeping anything tight

This is the answer to why implement dealerships don’t sell welding equipment.

Hire out the job??

or do what gunner, EdM, and a few others have said.

Just tag the nut. On a Brown tree cutter the blade nuts have to be tagged or they'll come loose.

Castle nuts and cotter pins- - - -after using a long wrench and some red loctitie. Once the nut is tight, then drill a hole through the castle area and insert a tight cotter pin.

I welded the damn nuts on there, I’ll cut them off if I ever need to remove gear box.

I used to triple nut one bolt on a Case mower.

I welded mine like you said can cut them off if needed. Damn brush hogs are a pain!

Nylon nuts on a Bush hog. Hilarious