Kraton How To Straighten Bent Dog Bones (Driveshafts)

[Mr.Duke]

I know I’ve covered this before but I think it was in the “what did you work on today” thread so I’ll make a dedicated thread on how to do this here since that’s what I’m working on at the moment.

If you haven’t bent a driveshaft or dog bone yet, give it some time, you’ll bend one eventually.

Yesterday I noticed that one of my rear shafts was bent, so here’s how I straighten them back out.
It’s an old man trick that I learned a long time ago called “the 3 bolt method”.

You will need a vice, 3 random bolts (doesn’t really matter what size) and a bent shaft.

Take your 3 bolts and arrange them in the vice like so...

Hold the position of the bolts and open the vice so that you can slide the shaft in between the 3 with the arch of the bend resting against the singe bolt

slowly close the vice and watch the shaft as you just want to hyperextend the bend in the opposite direction. Go slow, you can snap the shaft if you bend it back too much. Take the pressure off and see where the shaft flexes back. Repeat this process until it’s perfectly straight again.

Some are easy and you get it on one or two tries. Sometimes it takes a dozen or so before you find just the right amount of pressure needed to straighten it.

Done, and good as new.

Hope this helps.

 

[soSincerious]

the before shot looks like the way mine came from the factory

 

[Mattyd926]

I’ve been using a vice and a ball peen and what a pain in the arse. Going to try this 3 bolt method . I have a pile of bones I would love to be straight. Like ten bucks a pop.

What do you think about the 8mm titanium ones I’ve seen. Are they the best upgrade available? I told myself a long time ago I would just straighten rather than get new but I was younger and dumber.

 

[Notorious J]

I know I’ve covered this before but I think it was in the “what did you work on today” thread so I’ll make a dedicated thread on how to do this here since that’s what I’m working on at the moment.

If you haven’t bent a driveshaft or dog bone yet, give it some time, you’ll bend one eventually.

Yesterday I noticed that one of me rear shafts was bent so here’s how I straighten them back out.
It’s an old man trick that I learned a long time ago called “the 3 bolt method”.

You will need a vice, 3 random bolts (doesn’t really matter what size) and a bent shaft.

View attachment 66915

Take your 3 bolts and arrange them in the vice like so...
View attachment 66914

Hold the position of the bolts and open the vice so that you can slide the shaft in between the 3 with the arch of the bend resting against the singe bolt
View attachment 66916

slowly close the vice and watch the shaft as you just want to hyperextend the bend in the opposite direction. Go slow, you can snap the shaft if you bend it back too much. Take the pressure off and see where the shaft flexes back. Repeat this process until it’s perfectly straight again.

Some are easy and you get it on one or two tries. Sometimes it takes a dozen or so before you
the right amount of pressure needed to straighten it.

Done, and good as new.
View attachment 66917
View attachment 66918
Hope this helps.

Thanks @Mr.Duke. I've been using this method since the first time you showed us. I've managed to save a lot of drive shafts this way, and a lot of money too. Works just as effectively in a smaller vice as well. An extra person to help set it up is a good idea. They can hold two of the bolts in place while you hold the third and line up the driveshaft. Done it by myself plenty of times too, just with a lot more swearing when the bolts fall down and I have to start over.

 

[Mr.Duke]

Thanks @Mr.Duke. I've been using this method since the first time you showed us. I've managed to save a lot of drive shafts this way, and a lot of money too. Works just as effectively in a smaller vice as well. An extra person to help set it up is a good idea. They can hold two of the bolts in place while you hold the third and line up the driveshaft. Done it by myself plenty of times too, just with a lot more swearing when the bolts fall down and I have to start over.

Yeah....This is definitely one of those times in life where you wished you had three hands instead of just two. I’ve found that if you threaten the bolts and say mean things to them before you start the process they tend to behave better and not throw themselves on the floor as often. Every once in awhile you have to make an example out of one or more and throw them as far across the shop as possible then just go get a new one. ?

 

[adidas303]

'You'll need a vise, bolts and a bent shaft!' I think I've heard that somewhere else before!!

No, really thanks @Mr.Duke, that is a pretty invaluable tip there to save money and time!! ??

 

[jondilly1974]

Haven’t needed this yet but I’m glad you’ve shared it. ????

 

[Mr.Duke]

Here’s a pic from a front I attempted to straighten awhile back


I like to use bolts that aren’t threaded all the way up to give a smooth flat surface to press against.
I probably should’ve mentioned that I my OP

Actually... I think this was the one I snapped in two by going too far, too quickly

so don’t do that ^

 

[crimsonfancy]

I know I’ve covered this before but I think it was in the “what did you work on today” thread so I’ll make a dedicated thread on how to do this here since that’s what I’m working on at the moment.

If you haven’t bent a driveshaft or dog bone yet, give it some time, you’ll bend one eventually.

Yesterday I noticed that one of my rear shafts was bent, so here’s how I straighten them back out.
It’s an old man trick that I learned a long time ago called “the 3 bolt method”.

You will need a vice, 3 random bolts (doesn’t really matter what size) and a bent shaft.

View attachment 66915

Take your 3 bolts and arrange them in the vice like so...
View attachment 66914

Hold the position of the bolts and open the vice so that you can slide the shaft in between the 3 with the arch of the bend resting against the singe bolt
View attachment 66916

slowly close the vice and watch the shaft as you just want to hyperextend the bend in the opposite direction. Go slow, you can snap the shaft if you bend it back too much. Take the pressure off and see where the shaft flexes back. Repeat this process until it’s perfectly straight again.

Some are easy and you get it on one or two tries. Sometimes it takes a dozen or so before you find just the right amount of pressure needed to straighten it.

Done, and good as new.
View attachment 66917
View attachment 66918
Hope this helps.

Solid gold for my needs right now.

 

[Armarookie43]

I know I’ve covered this before but I think it was in the “what did you work on today” thread so I’ll make a dedicated thread on how to do this here since that’s what I’m working on at the moment.

If you haven’t bent a driveshaft or dog bone yet, give it some time, you’ll bend one eventually.

Yesterday I noticed that one of my rear shafts was bent, so here’s how I straighten them back out.
It’s an old man trick that I learned a long time ago called “the 3 bolt method”.

You will need a vice, 3 random bolts (doesn’t really matter what size) and a bent shaft.

View attachment 66915

Take your 3 bolts and arrange them in the vice like so...
View attachment 66914

Hold the position of the bolts and open the vice so that you can slide the shaft in between the 3 with the arch of the bend resting against the singe bolt
View attachment 66916

slowly close the vice and watch the shaft as you just want to hyperextend the bend in the opposite direction. Go slow, you can snap the shaft if you bend it back too much. Take the pressure off and see where the shaft flexes back. Repeat this process until it’s perfectly straight again.

Some are easy and you get it on one or two tries. Sometimes it takes a dozen or so before you find just the right amount of pressure needed to straighten it.

Done, and good as new.
View attachment 66917
View attachment 66918
Hope this helps.

I just need a vise and workbench now. Thanks ?

 

[Clubin]

I beat them on a piece of wood with a hammer. Lol.

 

[werner sline]

I beat them on a piece of wood with a hammer. Lol.

so do i lol ! i noticed many little hammering with a light hammer work well ! easiest and fastest method

 

[Notorious J]

Here’s a pic from a front I attempted to straighten awhile back


I like to use bolts that aren’t threaded all the way up to give a smooth flat surface to press against.
I probably should’ve mentioned that I my OP
View attachment 66950
Actually... I think this was the one I snapped in two by going too far, too quickly
View attachment 66951

so don’t do that ^

Need to tag this for @Orebro80 and anyone else that might want to give straightening their axles a go. Thanks again @Mr.Duke

 

[Rcproponent]

Genius. Putting this one in my book of tricks. Thank you for sharing.

 

[werner sline]

 

[Rcproponent]

That looks pretty dangerous to the internal parts ?.. I think I’d rather take the axle out.

 

[Armarookie43]

That looks pretty dangerous to the internal parts ?.. I think I’d rather take the axle out.

Yeah, I would just do it outside. With my luck, I'll probably break the drive cup, or the control arm, or an internal gear ?

 

[Rcproponent]

Yeah, I would just do it outside. With my luck, I'll probably break the drive cup, or the control arm, or an internal gear ?

That’s the same thing I was thinking... I was thinking the little pins that hold the planetary gears haha

 

[werner sline]

Yeah, I would just do it outside. With my luck, I'll probably break the drive cup, or the control arm, or an internal gear ?

i used it a bunch of times and nothing broke ! just do it like i do ! there shouldn't be stress on the diff outdrive.
i don't have much time when bashing so i need quick fix !!

 

[Armarookie43]

That’s the same thing I was thinking... I was thinking the little pins that hold the planetary gears haha

I've found those broken from just driving my Arrma trucks ?. Imagine an indirect impact like that?