pto winch housing welding..... can it de done?

[shaun.paddy]

[url][/url]So, ive got a 70series pto winch fitted to the front of my safari. It needed a bit of bar work to wrap around it, so i brought a welder and bumbled my way through it. Completed bar, painted, fitted to truck, tightened bolts..... Now, my engineering skills arent real good, there was a little gap between the pto mounting bolt holes on the drive shaft end and my bar... There was a little tug of war as i thightened up the bolts, and then it happened, CRACK. The cast mounting bracket on the right side of the winch as you look at the truck from the front has snapped. Feck, you dumb bastard.

Can it be welded by an engineer or do i start looking for a replacement?

[callum007]

How did you manage to crack it? your bar work not all line up and you end up twisting it? If your mounting frame is all straigth and square those bolts should recieve next to no load on them other than the weight of the winch, so I would suspect that if you find a good engineer you'll be alright to have it fixed. You can weld cast metals, just needs the right know how..

[Crash bandicoot]

you see the bolts on the end of the housing on the side closest in the picture.

The trick is to get a steel ring made, with a pattern and holes that line up with those bolts on the end, then purchase longer bolts, say its a 10mm plate so the bolts will be 10 mm longer,

this will remove all the stress from the cast bracket.

here's an example

[IcedJohnno]

If it is a STEEL casting, it will be able to be arc welded with suitable preparation. Also could be MIGed, if using a structural type wire, and a good, read expensive, welder.

If it is a IRON casting, I would suggest getting an old-skool engineer to do a big heavy bronze weld using a forge, or large gas burner to preheat the casting, and a Gas welding plant. Again lots of weld prep, but a much bigger vee this time.
There are Arc rods suitable for iron castings, however they are not much use where there are structural type loads in tension. (pulling loads) These rods tend to make very hard welds which are brittle.

It is possible to distinguish if it is an iron or steel casting by looking at the sparks that come off an angle grinder when grinding the casting.
If they are dull red and sparkle / flare at the trailing end, then the casting is iron.
If the sparks are brighter and orange with no flare then the casting is likely to be steel.

You are going down the right track by taking this repair to a good engineer. The winch casting will see quite high loads when in use, and a failure under load could have serious consequences.
As both a practical tradesman, and qualified Mechanical Engineer, I do not recommend a repair of this type being conducted by an enthusiastic home engineer.

[DEATH_INC]

You are going down the right track by taking this repair to a good engineer. The winch casting will see quite high loads when in use, and a failure under load could have serious consequences.

Maybe, but the loading is being pulled into the break rather than trying to pull it apart. A half decent weld will hold that no problem.
I'd weld it, and make that plate arrangement pictured as well if you're worried about the strength.

[IcedJohnno]

You are going down the right track by taking this repair to a good engineer. The winch casting will see quite high loads when in use, and a failure under load could have serious consequences.

Maybe, but the loading is being pulled into the break rather than trying to pull it apart. A half decent weld will hold that no problem.
I'd weld it, and make that plate arrangement pictured as well if you're worried about the strength.

I see what you are getting at but dissagree.
Those bolt mounts on the front are designed to be part of the winch mount. Thus they will counter some of the torque loading generated by the winch load via the drum and worm box.
As such these bolts will see a tensile load in countering the torque.
(See the web added to the casting in the above photo to help react against the torque/ tensile loading)
The above drawing will help, however you are relying on the front faceplate not to twist.
As I wrote above, winches generate high loads. These are often higher than we perceive.

[shaun.paddy]

Thanks for the replys fellas. Im not 100% how i broke it, other than to say there was a gap of mayby 3/4mm where it bolted to the bar, i just cranked it up and then did a final tighten up of all the other bolts. There was some tension on the other bolt holes too and took some persuading to line up... Mostlikely the cause!

Its done now though, so time to fix it! The bolt on bracket looks like a good idea and most likely the cheapest and quickest. Good to see regardless of the casting it should be able to be repaired.... Thankfully, as ive just had a look on TM, not a cheap option to buy a new one.

Regardless of the repair i wont be doing anything other than removing the winch.

Thanks for the advice and pointing out a few options

[kbushnz]

One option could be to grind the whole lot off...
Make up a curved steel plate which could be bolted thru the casting... Say six grade 8's.... There is plenty of room on the inside...
Then you can weld any bracket you like to that plate and reinforce it....

[DEATH_INC]

I see what you are getting at but dissagree.
Those bolt mounts on the front are designed to be part of the winch mount. Thus they will counter some of the torque loading generated by the winch load via the drum and worm box.
As such these bolts will see a tensile load in countering the torque.
(See the web added to the casting in the above photo to help react against the torque/ tensile loading)
The above drawing will help, however you are relying on the front faceplate not to twist.
As I wrote above, winches generate high loads. These are often higher than we perceive.

Agreed, especially with a pto winch. (it is , isn't it?)

But in saying that, that musn't be the only mount, surely? If it is then I'll take it all back.....
Otherwise if it shares the load, then it will mostly only see a shear load which a decent weld will hold. Theres plenty of space to put a heap of weld into both sides to reinforce it a fair bit too. Especially combined with that plate setup.
Again, if the load on that part was THAT great, it'd need more bolts

[Sadam_Husain]

first thing sort out the misalignment problem thats stressing the winch mounts mate or you'll keep busting winches, you should be able to find someone to weld the mount back on for you, that'll get you going again while you keep you keep your eye on tradme and soon enough you'll find someone listing a winch only for a hundred bucks and grab it swap them over and keep the old one for a spare or spare parts