Backhoe Pin/Bushing replacement in Woods 750 Backhoe
- Thread starter Dataway
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OP
Dataway
Gold Member
The points that need the most work are Boom to main housing (the boom holes are egged), Boom to dipper (the boom holes are egged), both bucket pivots in the dipper. And the Boom Ram to main housing is sloppy ... problem is the slop seems to be in the Ram sleeve ... which was taking abuse because the boom to main housing pivot was so sloppy.
Any idea how to get the main swivel bearing off the kingpin? They appear to be pressed on. Can't remove the main housing from the frame because I can't get the bearings off the king pin. Not a huge deal, I would have like to replace the lower swivel bearing, and do a bit of welding on the housing ... but not absolutely necessary. Can do the welding in place if need be.
Pivots that need work circled in red, kingpin bearing in green.
Any idea how to get the main swivel bearing off the kingpin? They appear to be pressed on. Can't remove the main housing from the frame because I can't get the bearings off the king pin. Not a huge deal, I would have like to replace the lower swivel bearing, and do a bit of welding on the housing ... but not absolutely necessary. Can do the welding in place if need be.
Pivots that need work circled in red, kingpin bearing in green.
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I do a lot of line boring, usually larger holes on loaders , excavaters, etc
Go with the hard bushings,.003-.005 interference fit , pressed in frozen, then you might have to use a small grinding wheel and flap wheel for the finish fit, The smaller holes are actually harder to do, then say, a 4" hole.
Go with the hard bushings,.003-.005 interference fit , pressed in frozen, then you might have to use a small grinding wheel and flap wheel for the finish fit, The smaller holes are actually harder to do, then say, a 4" hole.
OP
Dataway
Gold Member
Thank you, I was wondering what the fit should be.
The line boring will be tough, the boring bar in my BP won't reach both sides at the same time, so I'm going to have to flip the boom over to bore the other side. I'll have to turn up a 1 1/4" rod to fit the finished hole on the far side, turn it down to 1" to fit a collet and use that to align the second hole. I'd use a big drill bit, but my guess is it would make the hole a couple thou to large.
The line boring will be tough, the boring bar in my BP won't reach both sides at the same time, so I'm going to have to flip the boom over to bore the other side. I'll have to turn up a 1 1/4" rod to fit the finished hole on the far side, turn it down to 1" to fit a collet and use that to align the second hole. I'd use a big drill bit, but my guess is it would make the hole a couple thou to large.
LD1
Epic Contributor
I hope you don't misunderstand that post. .003-.004 is for the OD of the bushing.
Pin to bushing needs to be clearance, not interference. 0.000-0.001 is what I would aim for.
Pin to bushing needs to be clearance, not interference. 0.000-0.001 is what I would aim for.
OP
Dataway
Gold Member
Was just thinking I could make up an 8" or so boring bar out of some 3/4 or 7/8" cold rolled, cut down a 1/4" carbide lathe tool and mount that with a set screw .... put the whole shebang in a collet and reach both holes at the same time. Although I wouldn't have the easy adjust ability of my regular boring head. Just thinking out loud, really don't want to have to flip the boom and realign it ... only weighs maybe 100 lbs ... but still would be a pain.
LD1
Epic Contributor
What does your boring head look like?
Instead of chucking direct In the collet, make a longer bar for the boring head. Just make sure the part is true in the mill.
Instead of chucking direct In the collet, make a longer bar for the boring head. Just make sure the part is true in the mill.
OP
Dataway
Gold Member
LD1 ... yep you beat me to it ... I was just thinking ... why not a longer boring bar in the head 
Although it only takes like a 1/2" OD bar ... so I'd have to go real slow ... but that's ok.
And yes ... I interchanged "interference" and "clearance" like a novice
Although it only takes like a 1/2" OD bar ... so I'd have to go real slow ... but that's ok.And yes ... I interchanged "interference" and "clearance" like a novice
TMGT
Elite Member
I made a line boring setup a couple years ago, pretty simple and works well.
I used spring bushings when I made my backhoe, pins were made out of 1144 stressproof.
Mcmastercarr has a decent selection of spring bushings.
My drive system, fixed at between .005-6in per rev.
I used spring bushings when I made my backhoe, pins were made out of 1144 stressproof.
Mcmastercarr has a decent selection of spring bushings.
My drive system, fixed at between .005-6in per rev.
OP
Dataway
Gold Member
TMGT ... very interesting ... on close examination of the part diagram it really looks like the OEM bushings for the earlier model BH750 are indeed straight slot spring bushings.
Just looked at the 1144 and ordered 3 feet .... yep, it's harder and 25% stronger than the 1045 I planned on using. Also ordered a pair of the spring bushings to take a look at them.
Thanks,
Just looked at the 1144 and ordered 3 feet .... yep, it's harder and 25% stronger than the 1045 I planned on using. Also ordered a pair of the spring bushings to take a look at them.
Thanks,