While I was digging in my 655C yesterday, the boom started hanging up while swinging. I got to looking, and found that the bushing that goes around the swing cylinder mount on the backhoe frame (Part 26 below), was rising up out of the mount. I was basically able to pull the bushing out the top of the swing cylinder. Looking today at parts list and the manual, it's not clear to me what holds this bushing in..? Is the top plate that goes across both swing cylinders, supposed to hold that bushing down? Or is the seal that goes in above the bushing just supposed to be a tight enough fit to hold that bushing down? I assumed there was going to be a C-Clip or something holding everything in, but I don't see that. Trying to figure out what I need to do tonight to fix this correctly, and make sure I don't have this bushing pop out again when I get back out there.
Looks like it is to be pressed in.
Well damn.. That's not great that it easily slid out then! Guess I'll take the retainer plate off tonight and see how badly it's worn. Hopefully can just replace the bushing, not the retainer plate..?
There are people hear who are a lot more qualified than I am. I was classically trained as a mechanic forty years ago but changed crafts thirty years ago. I took the swing cylinders out of my 555E recently and had them re-packed. I am certain the bushings were pressed in because they were tight. If the plate bore is out of round I would bore it true and use an oversized bushing. You could probably get it at McMaster Carr. Not too big of an issue if you have access to a mill and a lathe.
Wrong hear. Here more correct
This is from the service manual. Strangely it doesn't give any details on the bushing R&R.
Yeah, I glanced through the manual last night and couldn't even find a mention of the bushings. Figured I'd go read more closely when I get home tonight, but I'm not sure it covers them.
Well, I tore it down, tapped the bushing back into place and got it back together tonight. I had to work the bushing quite awhile to get it back on, but not really a tight press fit. Bushing looked fine though - no damage.. What are everyone’s thoughts on something like loctite 680 retaining compound for something like this? Is that a bad idea for any reason?
Depending on the gap and if the hole is still reasonably round a Loctite retainer could work but the bushing should be fairly tight. I used Loctite 660 on mine after welding and boring the swing pivot. 660 fills the largest gaps of the retaining compounds. I found some heat helps it cure but it only cures in the absence of air. If the gap is too big it won't cure. Loctite has a chart online showing the different retaining compounds and respective gaps they are good for.
Be generous with your grease gun after you repair it. If the bushing gets dry the pin it will force the bushing to turn in the bore it is pressed into.
I'm pretty generous with the grease. I try to grease every day before I start. This backhoe lived a long, hard life before me though. These things are the price I pay for being able to own a cheap hoe!
And... It stayed in about 5 minutes when I got back out there last night. Grabbing some Loctite 660 tonight - will see if that will hold it in.
Take a chipping hammer or an automatic center punch and stipple the crap out it first.
Not sure what you mean by stipple it? Just making indents in the press surface or something? Just dimpling it up?
You're swinging a massive amount of weight around. A loctite type product is not likely to hold it. Check with a machine shop and see what it would cost to fix it.
Understood. It's an hour of work for a chance, and I don't think the Loctite will do any harm. It's worth a try in my book, unless someone can point out some harm it would do. Getting this to a machine shop is a much larger task for me.. I will if I need to, but I'll exhaust other options first.
If it needs to be tapped back in place and is somewhat snug the Loctite could work. Everything needs to be really clean and I found warming things up makes the Loctite cure better. Just semi hot to the touch is enough. If the bore is out of round probably needs some welding to repair it.
Thank you! When I put it back in Monday night, it was tight. I had to work it pretty hard to get it on - that’s why I thought it might hold. Got it apart, all cleaned up and ready. Waiting for the Loctite 660 to show up tomorrow. I’ll put some heat to it before I put it on - good advice. Will let everyone know how it turns out!
Also to clarify - this bushing presses on around the shaft on the cylinder, then the cap plate that holds it in place slides over the pressed-on bushing. So it will require some rework of the cylinder if this doesn’t work.. Fingers crossed I don’t have to get into all that.
You have wear that you won't fix by replacing one bushing. Sometimes the solution is a cheap trick. A thousand hours from now, you won't even remember the fix.
Ok - I like this thinking! Might just go ahead and do that in addition to the loctite
I put the bushing back in Thursday night with the Loctite 660. It did last a whole 8 hour shift of pushing it hard digging out trees Friday night, but as we all knew it would - the bushing popped back out at the end of the night.. So…. (See pic). Thanks @Check Break !
Did the Loctite 660 cure for 24 hours? It's supposed to fill the largest gaps of Loctite retainers but maybe something like a backhoe swing works it loose due to different loads put on the bushing rather than a constant load like a shaft turning in a bushing??
With a little grease, she'll probably last another 10,000 hrs. Do you grease your pump drive? I don't have a cheap trick for a massive hole in the lower radiator tank.
The bottle said 1-2 hour cure time. I let it set for about 20 hours before using it again.. Pretty sure it was fully cured - it lasted for awhile. But I’d say there was just too much play, and too much torque applied by the cylinder pressure / movement. Not really the same forces as a typical bearing, here.
I assume you’re talking about the U-joint that drives the pump? I do grease it, but what a pain in the ass! I have to contort my arm, scrape it all up, and get a load of grease and grime in the scrapes to get that job done.. I think they could have done better with that one.
Yes. The pump drive has two grease points and they're the most aggravating on the machine. Every 50 hours or so. Give that driveline a good shake when you're in there. If it's getting loose, it's cheaper to replace before it takes out the radiator and damages the pump input shaft.
Noted! I’ll keep an eye on that
@Check Break I tilted my hydraulic radiator forward yesterday to clean the radiators, and remembered that you mentioned I should give the hydraulic pump shaft a good shake to check that it’s tight. Gave it a shake, and it wasn’t what I was expecting. The u-joints on the shaft seem to be fine, but the yoke to pump side connection seems to be loose. You can watch in the video below. I assume this is not normal, and needs to be addressed immediately?
It seems like the yokes on both sides should be tight and they both appear loose.
Yes. Seems to be worn. At the risk of sending you on a wild goose chase which will waste a few hours of your time in the event you determine otherwise, you need to pull the pump drive and look at the pump input shaft. What your video exhibits is wear between the pump drive and pump input shaft. If all the wear is in the pump drive, you can replace the worn yoke or the entire drive. If the wear is also in the input shaft, your price of admission just increased exponentially. Now, the cheap trick. If you have wear between the drive and input shaft and it's all in the drive yoke, replace the yolk. If there's also wear in the input shaft, and I suspect there is, shim the entire pump drive out from the damper pulley. You'll introduce new positive and negative splines to each other and she'll tighten up. Hard thick washers do the trick. You'll have to gauge the distance needed and it may take one or two tries before you get satisfaction. Now the good news. The last one I did on my own Ford was so long ago no one remembers the pump drive is shimmed. There's thousands of hours on those eight washers, and if I was using my head, I would have used the hard thick washers and only used four. Now, for the bad news. I'm running out of tricks so don't assume I have a trick for all of the headaches you will be facing. Just kidding. That being said, I'll drop another potential problem on you. The booms on some of the "C" models had metallurgy issues and liked to crack off just above the lower pivot pin. Not saying yours will do this, but keep an eye on her for developing cracks so you can head off trouble before it begins. So, in conclusion, as long as you don't mind being abused a little when you have a problem, ask away. If I have an answer, I'll send it your way. Almost forgot, thanks for uploading the video. Makes diagnosis 10x easier.
Haha! I like how you lead me into my problems 1 at a time. Manageable bites. I’ll see if I can finagle the washer trick! I’ve heard about the boom metallurgy problems and I’ve kept an eye out for it. No signs yet. I did have to weld my front bucket up over the weekend though - prying on a stump, I tore a section in the middle loose - about 6” tears on either side of center. I gave it some abuse after welding, and it’s holding so-far, fingers crossed! But bring on the abuse - it’s the least I expect for these great answers.
I’ll look again when I get into it, but my initial assessment was that only the pump side was loose. Does seem like they would both have to be loose to move like it is though - I will take a closer look.
I watched your video again 4-5x. Those u-joints may be shot. You'll know when you remove the pump drive. Your best bet may be to replace the pump drive and shim the new drive out from the damper pulley to get a new bite on the input shaft. There's aftermarket pump drives for less than CNH's outrageous prices. Have to think a bit to remember where I saw them.
I appreciate it. I sure don’t want to pay CNH prices for that pump. If I have this thing apart anyway, I’ll very likely replace u-joints while I’m in there. No point not to.. I’ll report back when I’ve had time to tear into it, but that may not be until this winter sometime. Getting into busy season with the rest of life here..
If you shear the roots with the backhoe bucket, the stump will push right out. Still do this when we take out walnuts at the end of their life. 25 years ago we dumped 48+ diameter fir trees the same way. Rip three sides with a D8, leaving the back side intact. Build an earth ramp against the stump and hit her as high as we could reach with the cutting bit.
I know the feeling.
Oh yeah, I agree - absolutely the only way to do it! I’ve dug about 100 medium to rather large trees out over the past 3 weeks. Was just trying to move one out of my way, lifting on a stump that still had a couple roots in the ground. Not my brightest moment, but I found the weak spot in the front bucket!
Loctite 660 is recommended to repair some splines as well.
Interesting! Something I can think about while I’m in there