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'06 Bobcat A300 Chaincase
- Thread starter DGODGR
- Start date
I don't know what the slack should be on that chain. I might be able to get that information for you. Can't your dealer find that out or do you have some reasons for asking here instead of them?
Judging by the size of the chain (it's pretty damn big) I would think it should last the life of the machine. How many hours are on your A300, and what symptoms led you to investigate the bearing?
Not knowing what part/s of the bearing are cracked, or how long the part was in service while damaged, is it possible that any slack you have would be from the bearing wear? Is the sprocket rubbing on the axle tube on your machine too? Are either of the sprockets (at the drive motor, or the axle end) getting cupped at the base of the teeth (are the teeth starting to look "hooked")?
Sorry to hear that you are having a similar issue. It's a PITA to fix, either way, but if I were having to fix it I would be very happy that is the front bearing instead of one of the rear bearings.
BTW, I saw you tried to contact me (for some reason I did not get a notification when the last (2) posts were posted to this thread) and, to answer your question, the MFR never did anything to help me (other than what I reported in the thread).
Our a300 only has 974 hrs on it
It was the outer race that was cracked
Yes the sprocket is rubbing the axle tube
As for the chain slack. I am comparing to the other three chains and the chain in question appears to have like 4 times the amount of slack. So we changed it. Which made no difference
You can see here that the sprocket is off
And we are talking to the dealer now they going to the rep. See we're that goes
Do u have pictures of the machining you did?
It was the outer race that was cracked
Yes the sprocket is rubbing the axle tube
As for the chain slack. I am comparing to the other three chains and the chain in question appears to have like 4 times the amount of slack. So we changed it. Which made no difference
You can see here that the sprocket is off
And we are talking to the dealer now they going to the rep. See we're that goes
Do u have pictures of the machining you did?
It looks to me like, if there is any interference, it's in the center around the hole for the axle. I'm not sure what could be causing this. It's a very small diameter and the only thing that would touch here would be the inner part of the bearing itself (shouldn't cause this as it turns with the axle and sprocket). Next in line, and actually closer to the sprocket, would be the snap ring that is supposed to retain the bearing. This I also have my doubts about that because it would have to eat through the end of the axle tube before it reached the snap ring. The only reason I doubt that this is occurring, based solely on the photos you have provided, is that I think it would be a larger diameter for any of those scenarios.
Where was this photo taken? Inside or outside of the machine? I can make out the sprocket (far right), the bearing retaining ring (snap ring), the bearing, and I think the axle (far left). What is the tapered object between the sprocket and the snap ring?
I still have my A300. It has about 3,200 hours on it now. I had to machine the back side of the boss on the sprocket (opposite side of the sprocket as shown in your photos. Sorry, I don't have any pictures of the bosses after I had them machined. Look at the first (2) photos in post #4 & #5. They show the galling of the boss where it was interfering with the (inboard-inside the chain case) end of the axle tube. My machinist cut a shoulder (about 1/2" x 1/2") from the edge of the boss, to ensure clearance. At this point I think the axle would have to fall out before the sprocket could contact the axle tubes. In any case, the way I machined them would not make a difference in your case (wrong side of the sprocket).
Looking at the last picture you see the bevel. That is the sprocket. And you are looking at the axle mocked up on the bench. So between the bevel and snap ring is were there bearing boss from the inside the chain case should be. Thus no clearance.
So yes this is all out of the machine. And it appears that the rear sprockets are in the big side out and the front sprockets are the small side out.
But it is most likely a clearance issue as you can see the rubbing on the snap wing outer boss so a little machining is in order I am thinking
We have an email into the dealer were the machine was purchased and they said they will forward it to the western rep.
So we will see where that goes
Can't remember how to post pics lol
But we put the machine back to together the front sprocket was machined
But would you guess we still have grinding noises in the chain case. And it is now sounding from the left rear ....F M L
Now we do have a call into the western rep. My boss gunna call him in the morning
See where that goes. Hope it goes well
But we put the machine back to together the front sprocket was machined
But would you guess we still have grinding noises in the chain case. And it is now sounding from the left rear ....F M L
Now we do have a call into the western rep. My boss gunna call him in the morning
See where that goes. Hope it goes well
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Did you ever figure out why the one drive chain had so much slack? My A300 doesn't make any grinding noise in low range but in high range it makes some noise upon initial acceleration. Really it's more of a "clunking" noise. It sounds like the chains are making noise. I hope this all works out for you.
MatthewG
Active Member
Im curious how much noise from the chains is normal. I just bought an 05 A300 with only 29 hours, yes 29 one owner never used hours. It makes some chain case noise, but it might be normal??
The only chain noise that I hear, with my '06 A300, is upon initial acceleration, or heavy torque loads (like going up a steep hill) in 2nd speed (high range). I hope that this is helpful. Trying to explain how much noise via typing can be difficult.
CRAFT
Senior Member
MatthewG : They do make a chain case noise but mostly in hi-gear …… I complained about it when my machine was new too ….. told to me by the Tech's that the Butterfly chain size is a "REALLY" large gauge (size, pitch), much larger pitch than most of the competition …….. that was back in '07 …. it's now just shy of 4000 hrs and it's still making the same noise with no change, but when u'r not accustomed to these strange sounds it'll give an initial cause to worry … LOL ….
CRAFT
Senior Member
What Do YOU Mean that you can't explain how much noise via Typing ??????? ………… LMFAO !!! …….. Just pulling your Leg, but that's hard to describe via "Typing" Too … LOL
I saw something on YouTube (HowIDidIt is the channel-has great information on Bobcat repairs) that reminded me of this thread.
After re-reading my thread today, I felt as like I should share some more info.
When my neighbor machined the bosses on the sprockets he had to make a shoulder instead of a bevel. This was because the bosses were not centered on the sprockets so they rotated concentrically when on the lathe. I'm pretty sure that the spline drive was machined in the center of the axle but the boss being concentric allowed them to interfere with the bearing carrier/axle tube. Bobcat did not like the shoulder and told me that this would lead to failure. I installed them anyway and we have not had any problems to date. This thread was started in 2011 and we are now in 2023. The machine now has over 6,000 hours on it (4,000 hours of operation since repair was performed) and still no issues with the sprockets. YAY!
Another interesting tidbit: As I think that I had reported at the beginning of this thread, my Bobcat dealer had told told me that, not only had they never seen such an issue as this, but they had never even heard of this happening before either (many of those who replied to this thread reported that they were told the same song and dance by their dealers as well). Well!....This must be a very rare occurrence then!! Lucky me!...I would sooner have found the golden goose to hear them tell it. After my neighbor had machined the sprockets, he dropped them off on my front porch. While they were on the porch I heard a knock at the door. When I answered the door, I was greeted by a Jehovah's witness. After I politely indicated that I had no interest in subscribing to his religious protocols, he pointed at my sprockets and asked if they were from a Bobcat skid steer. "Why yes, they are....My neighbor must have dropped those off after machining them" I replied. He then proceeded to tell me about his 753 having the exact same issue several years prior. This was from a total stranger, and without any prompting what-so-ever. Hmmm....
After re-reading my thread today, I felt as like I should share some more info.
When my neighbor machined the bosses on the sprockets he had to make a shoulder instead of a bevel. This was because the bosses were not centered on the sprockets so they rotated concentrically when on the lathe. I'm pretty sure that the spline drive was machined in the center of the axle but the boss being concentric allowed them to interfere with the bearing carrier/axle tube. Bobcat did not like the shoulder and told me that this would lead to failure. I installed them anyway and we have not had any problems to date. This thread was started in 2011 and we are now in 2023. The machine now has over 6,000 hours on it (4,000 hours of operation since repair was performed) and still no issues with the sprockets. YAY!
Another interesting tidbit: As I think that I had reported at the beginning of this thread, my Bobcat dealer had told told me that, not only had they never seen such an issue as this, but they had never even heard of this happening before either (many of those who replied to this thread reported that they were told the same song and dance by their dealers as well). Well!....This must be a very rare occurrence then!! Lucky me!...I would sooner have found the golden goose to hear them tell it. After my neighbor had machined the sprockets, he dropped them off on my front porch. While they were on the porch I heard a knock at the door. When I answered the door, I was greeted by a Jehovah's witness. After I politely indicated that I had no interest in subscribing to his religious protocols, he pointed at my sprockets and asked if they were from a Bobcat skid steer. "Why yes, they are....My neighbor must have dropped those off after machining them" I replied. He then proceeded to tell me about his 753 having the exact same issue several years prior. This was from a total stranger, and without any prompting what-so-ever. Hmmm....
Bobcat Crazy
Senior Member
That is very interesting, the dealer has never heard of the issue before, and you had someone show up at your door the same day your parts came home from your neighbor who had experienced the same issue. What a coincidence! The guy showing up at your door I mean. I am certainly not saying it was a coincidence that you feel the Bobcat dealer might have told you something that is untrue!
I know for sure the Bobcat dealer where I buy parts has told me things about my machine that was not true. And it didn't take a genius to figure out what they had told me on more than one occasion was not true. They just thought that I didn't know any better.
I am not going to say that the guy running the parts counter at my local Bobcat place is a straight up liar, though I have enough evidence to say that. But I will just say he handles the truth mighty carelessly!!!!
After all this guy just works for the dealer/owner and I cannot not say that the dealer would approve of how careless his parts manager handles the truth.
But it is very disappointing when you go to place of business with trust in them to lead you in the right direction and while you are talking with the person you feel sure that he is not being truthful. Then when you get deeper into the repairs on your machine you find indisputable evidence that proves what you thought was correct, (that what he was telling you was straight up untrue).
In the end some people have character and some people don't. And once a person proves he has no character then you know how to deal with them.
I will get off of my Bobcat dealer soapbox now.
Bobcat Crazy
I struggle to stay off the soap box myself. When you think about it, having integrity is really only hard when you might be trying to avoid being responsible for your actions. It's just a choice.
I forgot to mention one other thing. After the Bobcat guys put my machine back to together, I had to back in there and fix their work. On my first job, we had to drive up a ramp to get over a 4' retaining wall, so we could access the site. The machine kept leaving a trail of oil when going over it. It wasn't a particularly hard fix (they forgot to install a couple of the bolts in the back chain case cover) but I was surely unhappy after paying the "experts" to put the machine back together.
I forgot to mention one other thing. After the Bobcat guys put my machine back to together, I had to back in there and fix their work. On my first job, we had to drive up a ramp to get over a 4' retaining wall, so we could access the site. The machine kept leaving a trail of oil when going over it. It wasn't a particularly hard fix (they forgot to install a couple of the bolts in the back chain case cover) but I was surely unhappy after paying the "experts" to put the machine back together.