Removing pins on BH90 - help!

5030tinkerer · Apr 15, 2006

I am wanting to install my new 36" BH90 backhoe bucket (that sucker is a MONSTER!). I went to remove the two pins, though, and had some trouble. The top pin eventually came out after some coaxing with an 8# sledgehammer, but the bottom pin will only budge side to side perhaps a 1/4". I even tried using a 3 point puller on it to no avail - it broke the puller (granted, it was from Harbor Freight...). Any clues on how to get this darned thing out? I did note that the upper pin sleeve was badly rutted, making me wonder how often the previous owner lubed the machine. The current plan is to pick up another, beefier puller from Sears or simply borrow one from the local AutoZone and try again.

I think I'll be contacting my local dealer or a machine shop to get a new sleeve in the upper (and likely lower) pin areas, but for now would just be happy with being able to remove the old lower pin for now. Any suggestions?

john_bud · Apr 15, 2006

Yeah, I am putting new pins and bushings in a hoe now and it can be "fun". First off, is all the weight off of the bucket? If the boom or dipper stick are setting down the pin ain't gonna move. Second, can you rotate the pin if you grab it with a vice grip? Some times they can get bent into a banana shape. That's "Bad". They are real real real hard to get out if they are bent. And they are fully hardended and will dull a blade in seconds.

Have you (or can you) pound from both directions? Little one way then a little the other? Have you greased it up, used penetrating oil?

One thing to remember as you pound with that sledge. If you mushroom the head of the pin, you are making trouble. Before you whack too much, call Kubota and ask how much a replacement pin costs. My hoe is an old Ford and the dealer wanted $259.99 for the boom to dipper stick pin. (I got off the floor and politely said no as I walked out the door!!!)

jb

5030tinkerer · Apr 18, 2006

Yes, all the weight is off of the bucket (with the exception of the bucket itself - sort of hard to find the happy medium between resting the bucket on the ground and too much down pressure). I tried a 7 ton puller on it the other day, but didn't have the mushroom plug on the end of it - only the pointed tip. I used a hex nut to serve as a holding point for the tip while preventing gouging the pin with the pointed tip. The puller promptly tore through the nut and began penetrating the pin. I am planning on picking up a hardened nut and trying again when I get back in town Saturday. I can move the pin side to side about a 1/4" by hammering it from each side, but that is all the movement I get. I hadn't considered the possibility of the pin being bent, but perhaps that is the problem. If upgrading to hardened nut doesn't work (likely as a result of the pin being bent), what are the other options for getting that sucker out of there? I can't imagine drilling it out.... /forums/images/graemlins/frown.gif

The bucket swings quite freely with just the one pin in, so that certainly supports the bent pin theory. /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif

I'll call my local dealer to see about the pin and bushing prices before I go with the drilling route, regardless. I am now an even firmer believer in timely greasing of all points. Perhaps that could have prevented this. Any and all other ideas welcome.

CTyler · Apr 18, 2006

If you have an air hammer you can try this.

Drill a small divet in the end of the pin. This gives the air hammer punch bit a place to sit without wandering around.
Pull the trigger and have at it.

5030tinkerer · Apr 24, 2006

Well, the pin is finally out. I used a 7 ton, 3 jaw puller to do it, along with a three foot long cheater bar. The threads on the puller even got damaged (despite being greased) during the process. I tried putting a nut and then even a grade 8 nut at the end of the puller to prevent the pointed tip from penetrating the bh pin, but that method just resulted in trashed nuts - the bolt just drove through the nut like it wasn't there. Getting ready to give up after trying a little (not a bunch at all) heat, penetrating oil, sledgehammers, etc, I was thinking about trying to get a reciprocating saw in the groove between the bucket and the backhoe when my wife suggested that I just take the chance of the pin mushrooming and getting damaged by allowing the bolt of the puller to penetrate the pin itself (since I was already desperate and getting ready to attempt cutting the pin anyway). I used 1/8" angle to give the puller jaws something other than just the bucket to grab on to (earlier attempts resulted in some minor damage to the bucket). After I could hardly turn the bolt any more (I was giving it all I had with that 3 foot cheater and I am not a small guy at 220 pounds...), I heard a crack. Thinking I broke something, but finding nothing broken, I turned the bolt some more. After hearing more cracking noises with each partial turn, I could see that the pin was beginning to move. An HOUR of turning it later (this was in the field without the benefit of air tools), the pin was finally out. It had a healthy rust scale coating on it, but no damage. I used some fine sandpaper to remove the scale and the pin slid in and out like butter. What a pain! I will never, ever allow pins to go ungreased. Thanks for all the support, guys. BTW, the new 36" bucket is incredible. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif