straightening a threaded rod

ducks13 · May 8, 2011

I recently got a JD 4410 and it has one problem that the part is a little pricy, about $300 so I'd really like to be able to straighten this threaded rod that is part of the 3 pt. lift rod assembly.

I tried heating it with rosebud and then screwing it into the casting but it seem to cool off too quick to effectively bend it. I may just not be getting it hot enough to start with but I am questioning my technique. Any of you have any great methods for straightening something like this? I've also thought about just bending it the best I can by just heating the spot where it is bent and then running a threading die over it but you have to be able to screw the rod almost all the way in in order to get out a roll pin that stops the shaft from coming too far out of the fitting. Anyone know where I could just by the shaft, I believe it is 1/2" and of course needs a L.H thread on one end.

Thanks for any suggestions and observation you may have.

Don87 · May 8, 2011

If it's tempered steel, you lost the temper with the first heating and cooling cycle.

mrmikey · May 8, 2011

A press and a couple of pieces of hardwood or aluminum to protect the treads is your best bet.....Mike

kennyd · May 8, 2011

Is that the top-link? If so generic ones are available for a lot less than OEM.

SPYDERLK · May 8, 2011

Do you have any nuts to fit that thread? They would work well as brace points to control the bend position w/o pulling heat out too fast in the vise. You could split one and use it around the rod. Set it close to the bend about 2 threads off the bend. Heat the bend and force the end sideways to straighten. A couple steps and adjustments depending on how the straightening bending occurs, and youll have it.
larry

ducks13 · May 8, 2011

Kenny,

No, it is the side link. JD parts seems to indicate that I need an LVA 14231 for $230. Do you have any idea what this piece looks like, I can't seem to find an illustration in the catalog. Heck, at that price a hydrulic link would seem like the way to go :licking: . . . of course then I'd have to buy the hydrulics to go with it.

The Haymaker · May 8, 2011

mrmikey said:
A press and a couple of pieces of hardwood or aluminum to protect the treads is your best bet.....Mike

This.

RoyJackson · May 8, 2011

kennyd said:
Is that the top-link? If so generic ones are available for a lot less than OEM.

That's the right side leveling adjustment for the lower links (the handle is the giveaway).

I've worked around machining most of my life. Frankly, fixing a bent threaded rod isn't normally too successful. The required clearances and thread geometry just don't lend themselves to that kind of repair. That, and the metal tries to "springback" which means you may have to try to over bend it in the direction opposite of the original bend. A real PITA.

Just because Deere wants $300, it doesn't mean you can't find one on eBay or another source. This is also a component you could buy from a tractor salvage yard. It's the same unit used on the 4200, 4300, 4400, 4210 and 4310. I wouldn't be to surprised if it's used on the newer 3x20 series Deeres too.

But if you do straighten it to what you think will work, find a nut that you can run up the thread to ensure it runs free. That's cheaper then stripping another Deere component on your tractor.

Good luck!!

SPYDERLK · May 8, 2011

RoyJackson said:
I've worked around machining most of my life. Frankly, fixing a bent threaded rod isn't normally too successful. The required clearances and thread geometry just don't lend themselves to that kind of repair. That, and the metal tries to "springback" which means you may have to try to over bend it in the direction opposite of the original bend. A real PITA.
But if you do straighten it to what you think will work, find a nut that you can run up the thread to ensure it runs free. That's cheaper then stripping another Deere component on your tractor.

I have succeeded on all the ones I have attempted. The key is good thread conformed support at the bend point, some heat, and observation with pertinent adjustment during the process... and of course not too bad a bend in the 1st place. The bend shown will straighten well.
larry

RoyJackson · May 8, 2011

SPYDERLK said:
I have succeeded on all the ones I have attempted. The key is good thread conformed support at the bend point, some heat, and observation with pertinent adjustment during the process... and of course not too bad a bend in the 1st place. The bend shown will straighten well.
larry

~~I guess ducks13 will find out...~~

ducks13 · May 8, 2011

Since I don't own a press Larry's method sounds the best. It seems challanging like Roy says. I think I will give it another shot using the lower fitting for the bend support. It should work as well as a split nut. I think I may have been too easy on the heat, I never really got it rod hot so I could bend it with just had force.

SPYDERLK · May 8, 2011

ducks13 said:
Since I don't own a press Larry's method sounds the best. It seems challanging like Roy says. I think I will give it another shot using the lower fitting for the bend support. It should work as well as a split nut. I think I may have been too easy on the heat, I never really got it rod hot so I could bend it with just had force.

I think you used enuf heat, but not enuf force. As said by another poster, heat above a certain amount will change the metallurgy of the rod and leave it less durable. 600F is safe -- above that youre losing some of the good properties. As I recall you heated it and tried to screw it into the straight female thread to get it straight. Not effective [this does not cause very much straightening force] and a great danger of getting it galled and stuck. You need heat and sideforce, whether with a split nut, block of wood and hammer, or a lever of some sort. You will need to observe well and probably make adjustments to assure it is always bending in the place you want it to. I have straightened about 8 similarly and slightly worse bent rods. They seem as good as new. Just take care, and good luck.
larry

pat32rf · May 10, 2011

Now ya'll got me worried....mine has a bit of a "kick" in it so I can only turn it so far. If I need more adjustment I pull a pin and twist the free end.
Just how did it get bent?

SPYDERLK · May 10, 2011

Mighta pried against something as you raised or lowered.
larry

RoyJackson · May 10, 2011

SPYDERLK said:
Mighta pried against something as you raised or lowered.
larry

Or backed into an implement...
The adjustable link is pretty exposed to damage.

RoMad · May 10, 2011

I have straightened out all thread that isn't bent too bad without any heat. A press would be nice but you can do it simpler. Lay a piece of good hard oak or ash on your flat garage floor or sidewalk, lay another piece on top of it and hit the top piece pretty hard with an 8lb. sledge hammer. You may need to lay each end on a seperate board and put your top board on the middle with the bend up and give it a good whack. I have three sons and we have straightened out bent shafts, bent atv axles etc. with this method. After you get finished beating on it clean up the threads a little with a file and you should be good to go. It really isn't that hard to do.

RippySkippy · May 10, 2011

ducks13 said:
Kenny,

No, it is the side link. JD parts seems to indicate that I need an LVA 14231 for $230. Do you have any idea what this piece looks like, I can't seem to find an illustration in the catalog. Heck, at that price a hydrulic link would seem like the way to go :licking: . . . of course then I'd have to buy the hydrulics to go with it.

Maybe these documents will help...

View attachment GreaterThanh14139.pdf

View attachment LessThanH141318.pdf

Soundguy · May 11, 2011

i'd cut and paste.. i've don that to ford side links transplanting thread from allthread or hard bolts.

straightening a bent threaded rod is just to fraught to fail again.

either cut n paste, or adapt one from a generic application.. or get a salvage one.

soundguy

RoyJackson · May 11, 2011

RippySkippy said:
Maybe these documents will help...
View attachment 212164

View attachment 212165

View attachment 212166

View attachment 212167

If those components are available for sale as individual parts, replacement would be a good idea...

SPYDERLK · May 11, 2011

Soundguy said:
i'd cut and paste.. i've don that to ford side links transplanting thread from allthread or hard bolts.

straightening a bent threaded rod is just to fraught to fail again.

either cut n paste, or adapt one from a generic application.. or get a salvage one.

soundguy

Ive cut and pasted when the thread was too bent. Of the ones Ive pasted, or just straightened, none had failed in the 1st place - but had been damaged by side forces. The ones straightened have not been re damaged or failed in use or been damaged in any way by their use as a link. They do what they were designed for. These things can be fixed in the time it takes to find and acquire a replacement.
larry