Ford 550 Backhoe - Swing arm motion is very slow to stop.

[thahn1608]

I have a Ford 550 Backhoe that I've done a good bit of work to, but I have a problem and really don't want to spend a lot of money chasing what could be a simple fix - so I'm relying on the advice of those who have had similar problems.

Besides the tractor being a beast (it will rip the bucket in half before it stops digging), it has a few quirks that I've been trying to iron out. The main one is the swing cylinders. I've rebuilt both of them - one blew and I figured since I had everything apart I'd go ahead and rebuild the other. This machine has 2 single acting cylinders that pull a chain to turn swing the hoe. Great concept, but how do you tighten the response time? When the 15' hoe is swinging full out and I let go of the lever it swings for another 3-4 feet before it comes to a soft rest. As you can imagine it makes it a little hard to dig a ditch this way. it's not because the bushings of the hoe are worn because they're actually pretty tight. It's like there's a bypass valve that is kicking in causing it to come to a slow stop instead of stopping where I want it to.

Any suggestions?

 

[DJ54]

I started out running hoe on a '76 model 550. Loved that thing..!! If you're swinging fully extended, it could very well be. That's a lot of leverage out there with that much weight in the bucket.

I might suggest changing how you dig. Basically, shave a little on a full pass, enough to get a full bucket crowding, stick up, and curling the bucket, to keep the cut somewhat flat, but tapering up to ground level. Swing when in close, and in the dump cycle, extend, lower, and uncurl the bucket. Doing 2-3 actions at once takes lot of shock off the hydraulics. When you swing back to drop in the trench, you can lower the boom, and kill some of the swing action. After your trench is started at full depth, move ahead maybe 3/4 of the distance to reach where you left off digging at full depth. This will give you enough reach to clean up, back of where you left off. Plus allow for another action, maybe crowding in a bit, to kill more of the swing action.

You just have to learn to feather the controls, and do a couple things at once. If it's a 4-sticker, it's pretty easy to do after a while. Just takes seat time. I'm sure this is about as clear as mud by now...

Not sure what RPM's you're running when digging, but I used to set our 550 @ 2000 rpm. It took that rpm to do several functions, and be smooth. Again, that was after probably 4-500 hrs seat time. Start at a lower rpm, and work your way up. Enough seat time, and the bucket at the end of the boom, will seem like an extension of your arm and hand. You won't even be concentrating on what levers your hands are moving, but rather you'll be concentrating on that bucket, and what you're wanting to do with it. It just seems to come as second nature after a while.

On the other hand, climbing on a different machine, with different controls is a whole new learning curve, LOL... Been there, done that...

Be sure and check the U-joint on the drive shaft of the front mounted hyd. pump. It's in a nasty place, under the front radiator shroud. Unless they have cut holes through the sides like our mechanic did, so I could grease it, there was no way to get to it, other than removing that whole front shroud.

Hope this helps..!!

 

[thahn1608]

Thanks. I've had this machine for several years and know it quite well. I'm thinking there's something that is worn out. It does it whether it's empty, full, extended or folded up. I would like to fix it if I knew where to start looking... I could rebuild the control valves, replace the relief valve, or something else. I'd just like to not throw money at something that isn't causing the problem. It has to be something in the swing circuit though. Thanks!

 

[DJ54]

You might try raising it up on one outrigger enough to see if when the boom is extended some, will drift to the lower side. Since you've rebuilt the cylinders, could very well be the valve body needs rebuilt.

 

[DJ54]

Did a quick look at New Holland Construction NEW HOLLAND CONSTRUCTION | BUILT AROUND YOU and found the below attached exploded view of the cushioning valve on the 550. Don't have a clue where it's located, but you can bet it's safely tucked under the floor pan.

Don't suppose you have a service manual..??

And if memory serves me correctly, seems ours had a spring loaded lever that would catch the boom when at about 60 degree swing that was linked to the swing lever. It would pull it back towards center, to soften the swing. Really aggravating if you run it all day. Smoke wrench took care of that...

If you use the link above, you can find your model, and find the exploded view of the hyd. assy's.

 

[RogerWD]

I wanted to replace the fan belt on my Ford 550 Backhoe. It looks like I have to remove the drive shaft for the hydraulic pump but I'm having trouble getting a wrench on the bolts. Is there a better way to replace the belt?