Alternative to Line Boring

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TriHonu

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Apr 15, 2007
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I am getting close to fixing the slop in my tilt cylinder bosses. (They are really bad!) I had seen an advertisement in one of the trade publications for expanding pins from ExpanderSystem.com. These pins have a taper at each end with a tapered bushing. You install the pin and tighten the nuts at each end and the bushing is forced up the taper and expands to fill the wear in the mounting bosses.
On the website I opened the product catalog and found they make pins specifically for the tilt cylinder on my 763. They make two different series, one that will handle up to 2mm wear the other will handle up to 4mm wear.
I called the local dealer and got some pricing. They quoted me $240 for the pin. They are a new distributor and have only sold about a dozen pins so far.
Have any of you tried these pins?
 

140mower

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Jun 4, 2006
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I looked into going this route with my 763, and would have done it if I had been quoted the price that you were. I asked around with several of the local logging outfits around here, and found several that had used them and all were very happy with the results. I can't remember the exact price I was quoted, but it was over $450 for one pin through our local machine shop/ dealer. Needless to say I told them to pound sand and decided to just live with the slop until I came up with another solution. What I finally did was weld stringers (beads) into the bosses and die ground them back out and hoped for the best, going on a year now and no broken parts so I figure I got it pretty close. I would have rather gone with the expander pin, but it was just a little too costly at the time.
Don
 

Tazza

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I looked into going this route with my 763, and would have done it if I had been quoted the price that you were. I asked around with several of the local logging outfits around here, and found several that had used them and all were very happy with the results. I can't remember the exact price I was quoted, but it was over $450 for one pin through our local machine shop/ dealer. Needless to say I told them to pound sand and decided to just live with the slop until I came up with another solution. What I finally did was weld stringers (beads) into the bosses and die ground them back out and hoped for the best, going on a year now and no broken parts so I figure I got it pretty close. I would have rather gone with the expander pin, but it was just a little too costly at the time.
Don
If you have the time and gear, you could look into grinding the old bosses out and make new ones and weld them in. I have done this on a few machines. All it cost me was time, i have a fair bit of old chrome bar i machine down to suit.
 

skidsteer.ca

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Jan 20, 2006
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If you have the time and gear, you could look into grinding the old bosses out and make new ones and weld them in. I have done this on a few machines. All it cost me was time, i have a fair bit of old chrome bar i machine down to suit.
I too built new bosses and welded them nplace of the old on both my 553 and 853. Results are performing well and cost was minimal, but time consuming. I had a fellow look at it for line boring but was told there was too little meat in the boss.
Ken
 

Tazza

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I too built new bosses and welded them nplace of the old on both my 553 and 853. Results are performing well and cost was minimal, but time consuming. I had a fellow look at it for line boring but was told there was too little meat in the boss.
Ken
Another good point, and when you machine new ones and weld them in, its back to standard size too.
 

latrobe

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Feb 5, 2008
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Another good point, and when you machine new ones and weld them in, its back to standard size too.
I have not tried these pins, but I think they would work provided that the bore their meant to repair was not to out of round. I don't see how expanding a bushing in a egg shape hole would give the results your looking for. The bushing would only be hitting on two spots in the bore basically and it would move back and forth till it broke into pieces and did more damage and maybe even get stuck If the bores were within 0.005 of an inch of being true I think it would be alright, just my opinion. And good luck.
 

Tazza

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I have not tried these pins, but I think they would work provided that the bore their meant to repair was not to out of round. I don't see how expanding a bushing in a egg shape hole would give the results your looking for. The bushing would only be hitting on two spots in the bore basically and it would move back and forth till it broke into pieces and did more damage and maybe even get stuck If the bores were within 0.005 of an inch of being true I think it would be alright, just my opinion. And good luck.
The way i understand that they work is the ends expand out to give you a secure fit on the bosses. The inside is still a round shaft that is matched to the bushings inside the end of the ram. The eye on the end of the ram has replaceable bushings inside it, so they can be easily changed to bring it back to the rite size.
 
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TriHonu

TriHonu

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Apr 15, 2007
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The way i understand that they work is the ends expand out to give you a secure fit on the bosses. The inside is still a round shaft that is matched to the bushings inside the end of the ram. The eye on the end of the ram has replaceable bushings inside it, so they can be easily changed to bring it back to the rite size.
I asked the sales rep about out of round holes. He stated the bushing has a reasonable amount of ductility and will crush to fit some hole elongation. He stated that you may have to re-torque the bolts a few times after install as the bushing continues to further seat.
I talked to my Bobcat dealer about these pins. The ears on the Quicktach with a single tilt cylinder are a known weak point. He was really interested in this product. He tells me a new bare Quicktach plate is approaching $900. So $240 for a bolt on fix may be a very reasonable fix for those without the time or tools to fix it themselves.
Unlucky for me my mount had already been bored and bushed and has now failed for the second time. I'm going to use a hole-saw to cut 1 7/8" holes and I have 2" bushing stock that I am going to fit to the holes and extend out an additional inch outside the ears to effectively double the bearing surface of each ear.
 
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