Woods backhoe sub frame problems

[hr3]

Ok I have a woods backhoe and the bolts that attach the subframe to the rear axel keep coming loose.. Last year I took them all out and cleaned the threads real good and lock tited them back in,,About 3 months later one was loose,, So I tightened it and welded all the heads to the subframe so they wouldn't come loose again,,

Well one just broke off again today,, ANY good ideas how I can fix this,???

 

[RoyJackson]

If you just tacked the bolt heads, grind down the tack and use an easy-out.
I suggest you use lockwashers next time, and make checking the bolt torque part of your routine.

 

[jimmysisson]

If you just tacked the bolt heads, grind down the tack and use an easy-out.
I suggest you use lockwashers next time, and make checking the bolt torque part of your routine.

+1 on checking torque. Would a nylock type nut stay tight? I've heard lock washers don't work so well.
Jim

 

[RoyJackson]

+1 on checking torque. Would a nylock type nut stay tight? I've heard lock washers don't work so well.
Jim

If they are through bolts. I thought they were in blind holes though...maybe the OP will confirm.
If he uses locknuts, I think he'll need longer bolts. You want at least one or two full threads through a lock nut.
Safest way might be to use longer bolts drilled for cotter keys and use castellated nuts.

 

[hr3]

Not through bolts they bolt into the alum axel housing.. I've used lock washers but to no avail.. As for torqueing I've had them come loose within a few hours with heavy use with the backhoe..

One that broke last year wouldn't come out so I put in a helicoil.. There is no shoulder on the bolts I'll try to find some that are but I'm still at a loss..

 

[RoyJackson]

Not through bolts they bolt into the alum axel housing.. I've used lock washers but to no avail.. As for torqueing I've had them come loose within a few hours with heavy use with the backhoe..

One that broke last year wouldn't come out so I put in a helicoil.. There is no shoulder on the bolts I'll try to find some that are but I'm still at a loss..

Since you wrote you have an aluminum axle housing, it's possible those threads are working. You might consider putting some type of solid insert (rather then a helicoil) in there. Before you do this, I suggest you contact the Woods engineering department and see what they suggest.

 

[Zebrafive]

Is it possible to install studs? You might have position the sub frame then install the studs thru it into your axle housing. I would be worried about stripping the threads of the axle housing using bolts. Studs will not be twisting in the axle housing threads. I think you could get higher torque on studs safely vs bolts. There are also various ways to lock the nuts on the studs, such as using castle nuts and cotter pins.

 

[Baby Grand]

Are you using a torque wrench to install the bolts?
Broken bolts is usually a sign of either overtorque, which results in excessive bolt preload or flange separation due to undertorque.

 

[hr3]

Is it possible to install studs? You might have position the sub frame then install the studs thru it into your axle housing. I would be worried about stripping the threads of the axle housing using bolts. Studs will not be twisting in the axle housing threads. I think you could get higher torque on studs safely vs bolts. There are also various ways to lock the nuts on the studs, such as using castle nuts and cotter pins.

I like the stud idea,, should I locktite the crap out of them if I put some in???

 

[hr3]

Are you using a torque wrench to install the bolts?
Broken bolts is usually a sign of either overtorque, which results in excessive bolt preload or flange separation due to undertorque.

Good idea I just looked in the book on the hoe and it dosn't even show the subframe.. ??