Heavy equipment repair experts

[theoldwizard1]

So I was watching a YouTube video the other day. A backhoe had a SERIOUS fitment problem !

The hoe fit a large (18" ?) male spline into a female socket on the tractor. The splines were severely worn !!

The only way it could think of to repair this was to cut what was left of the male and female splines off, machine a bushing that woul heat shrink into the female socket and the cut a massive key into both halves. 2 or more of these keys might be required given how much torque is applied as the hoe assembly rotates and abruptly stops.

EXPERTS PLEASE CHIME IN !

 

[Neggy]

replace the worn part or weld it and re-machine it

 

[zkdiesel]

Not your machine or your problem.
I have enough problems with equipment without looking for problems that don’t present itself

 

[metlmunchr]

Got a link to the video? We've got backhoes from Cat, Case, Ford, Dynahoe, Deere, JCB, Ditch Witch, and even an old IH, but I've never seen a hoe connected to the tractor with any sort of spline.

 

[scooby074]

Got a link to the video? We've got backhoes from Cat, Case, Ford, Dynahoe, Deere, JCB, Ditch Witch, and even an old IH, but I've never seen a hoe connected to the tractor with any sort of spline.

If its the video Im thinking of, the spline was on the swing motor. Not the best repair in my eyes but I think the parts were Obs. and they didnt want to spend a fortune on an old machine. A quick and dirty repair.

 

[Jlarson]

Machine shop fixes usually aren't my 1st or 2nd goto.

 

[Sumboodie]

If its the video Im thinking of, the spline was on the swing motor. Not the best repair in my eyes but I think the parts were Obs. and they didnt want to spend a fortune on an old machine. A quick and dirty repair.

Cessna swing motor?

 

[scooby074]

Cessna swing motor?

Yup.

 

[joe49]

What is the aplication are you writing about?

 

[Wrench97]

Sounds like the hoe on Watch Wes Work from a few months back>

If I remember correctly parts are obsolete and the hoe probably isn't worth the cost if they are available.

 

[Sumboodie]

What is the aplication are you writing about?

Backhoe probably. I know Massey Ferguson used them, probably a few other applications as well.

 

[theoldwizard1]

Sounds like the hoe on Watch Wes Work from a few months back>

If I remember correctly parts are obsolete and the hoe probably isn't worth the cost if they are available.

Yep !

 

[joe49]

Never worked on one of those. But it's junk either just run it or shim stock the spline to take up some of the play.

 

[lowrollin70gmc]

If the owner is aware of the slop and just wants it to stop leaking, I’d do exactly what the video does. Seal it up and send it out. I’d advise the owner to not use the boom swing to do any work, only swing with the bucket in free air. This would be annoying as an operator, but the price to pay for older gear. Eventually it will strip completely out, but that might be 10 or 20 years down the road if it’s a farm/ranch/homeowner machine that doesn’t log a lot of hours but is handy to have in the barn.

I wouldn’t trust keyways for the torque and fatigue of repeated back and forth of that swing motor. A machine shop could cut smaller (weaker) splines on the old shaft with a new bottom plate broached. An all new shaft and bottom retainer could be made as well. At that point, the cheaper option is selling the sloppy machine and buying a used machine without a splined swing motor.

 

[Bert_]

On that machine, you make the decision he did. Put it back together and run it until it breaks.

If it did strip and you have access to the bottom of that splined shaft I would be very tempted to weld it solid. Your not going to hurt the value...

 

[joe49]

I'm also with Bert direct drive works, welder up.

 

[American Locomotive]

While in the comments Wes said "you can't just take this shaft to a machine shop" - I'm really not so sure about that. The splines themselves are straight, and the "shaft" is conical - which makes the job a lot easier. Weld the shaft up with an appropriate welding rod (there are all kinds of different filler rods designed for applications like this) and then turn it down to the correct OD. Then you'd mount the whole shaft in a mill on a dividing head angled at whatever the taper is, and off you go.

The socket end could also be re-made. Mill out the basic shape out of a new block of 4140 or whatever. Broach or mill the taper, and then broach the splines as normal. Harden and heat-treat the part afterwards.

I'm not an expert by any means, but I suspect a competent shop with big machines could probably get it done in 10-12 hours of labor. Probably about $1,500-2,000 to get it done.

Pricey, but certainly beats the price of a replacement tractor and hoe.

Edit: Actually thinking about it, clearly the machine functions with a loose sloppy fit - so the taper isn't really necessary for proper function. Weld up the male splines, turn down, cut straight splines. Mill a new block (doesn't have to look fancy, so it can be rough milled), punch a hole and then broach some straight splines.

Done. Probably a days work or less - especially if you do your homework and provide some rough drawings of what you want and what splines you want.

 

[catalytic]

Assuming the part is steel and not hardened, a standard fix would be to chuck it into centers, add weld to build up the diameter, then re-machine the splines.

 

[IndyGarage]

While in the comments Wes said "you can't just take this shaft to a machine shop" - I'm really not so sure about that. The splines themselves are straight, and the "shaft" is conical - which makes the job a lot easier. Weld the shaft up with an appropriate welding rod (there are all kinds of different filler rods designed for applications like this) and then turn it down to the correct OD. Then you'd mount the whole shaft in a mill on a dividing head angled at whatever the taper is, and off you go.

The socket end could also be re-made. Mill out the basic shape out of a new block of 4140 or whatever. Broach or mill the taper, and then broach the splines as normal. Harden and heat-treat the part afterwards.

I'm not an expert by any means, but I suspect a competent shop with big machines could probably get it done in 10-12 hours of labor. Probably about $1,500-2,000 to get it done.

Pricey, but certainly beats the price of a replacement tractor and hoe.

Edit: Actually thinking about it, clearly the machine functions with a loose sloppy fit - so the taper isn't really necessary for proper function. Weld up the male splines, turn down, cut straight splines. Mill a new block (doesn't have to look fancy, so it can be rough milled), punch a hole and then broach some straight splines.

Done. Probably a days work or less - especially if you do your homework and provide some rough drawings of what you want and what splines you want.

This, could be done, but probably 3x as long as you think. then you are getting into the total value of the tractor.

My guess is the spline wasn't hardened or not very well hardened from the factory, which is why they wore so badly. Aerospace parts like that get repaired pretty frequently, but I don't think anybody makes money doing that for antique tractors.

I'd just look for some used parts that have life left and move on.

 

[Firebrick43]

Any backhoe using a swing motor design is trash, which is why they are usually cheap as no one that "knows" about backhoes will touch one. MF and IH backhoes come to mind, there is some JD backhoes on track loaders that were swing motors to due to lack of space for the cylinders

I have a friend that converted his MF to twin cylinder swing with plans from some where. Even then because of that and multiple other issues when he can across a low hour cherry 416 cat for moderate price (for the year, cheap for the hours) he sold the MF to some other sucker. He bought the MF without consulting anyone cause he thought it was a great deal. Found out later not so much.