I own a Bobcat 863 that leaks hydraulic oil internaly mostly when i am running attachments. I had the problem fixed by bobcat twice at $2500.00 each time but money is low and i have plenty of time to do it my self now. My question is does anyone know where these leaks are at? I was told it is coming from a hex nut plug down it the chain case or by the axles. I have tried to find it but no luck. Thanks Wayne
its you carrier seals they are in the chain case they are pretty simple to do if you have the correct tools take the front cover off the kick plate out the center cover off then take a 1 1/2 wrench break the bolts loose on the front axles turn them out about half way then take the tires off the front use a 16lb sledge beat the axle out loose the bolt the rest of the way beat it out more then remove it do the same for the other side then remove the brake disks if its not a 2 speed machine take the 2 carriage bolts out 1/2 wrench to take the nuts off then remove the snap ring on the carrier shaft repeat for the other side then remove the side cover plate pull the drive motor be careful not to drop the rotating group out of the motor as you pull it out ge *** about 1/2 in gap between the motor and carrier then put a big zip tie around the group tighten and pull the motor this is all after you determine which side its on and drain the chain case from the rear bottom of the machine there should be a drain plug under a cover then after the motors off remove the carrier bolts they are a 15/16 socket then slide the carrier towards the back and pull the chain off then the carrier will fit through the side cover plate you may have to work at it to get it out but it will fit then take a press remove the snap ring and press the shaft out replace the 2seals that face opposite of each other and put about .005 shim stock behind the bearing and put it back together check the shaft to make sure it is not grooved and reinstall the carrier make sure you get the bolts tight about 300 ft lbs a long handled snap on ratchet and a cheater bar will get them there or if you have a small enough impact you can run them down and then give them a turn with the ratchet make sure you pay attention to which way the carrier comes out because it will bolt up in any direction but your drive motor will not bolt up correctly if its not right you will need a front and center chain case cover gasket 2 carrier seals the six bolt gasket the gasket goop it comes in a cocking tube new drive motor o ring between the carrier and motor new drive hose o rings 2 axle seals wear rings if needed case drain filters change both of them also when you break the steering controls if its a g series make sure you scribe where they meet to make it easier to get your tracking back together straight that's about the jist of it its about a 8 hr job or more for your first time i can get it done in about 6 if i bust my balls and don't stop but i also cant :drinkup while im at work so it may take longer if i was at home doing it there you go any questions ask away
This is a little puzzling to me. The procedure for replacing the motor carrier seals by Bobcatmechanic is correct and good for "internal leakage". The symptom is your hydraulic tank level goes down, and your chaincase fills up. Machine stays dry until the chaincase overflows, then it leaks everywhere, coming out of the vent, seeping through the covers, even out of the axles. But this occurs when driving, as drive oil is getting through to the chaincase, and not necessarily when you are using attachments. Or could you be using something heavy that requires a lot of drive pressure when operating(blade, planer, trencher)? Also, if the repair for the carrier seals has been twice done, was it the same side or both sides? This repair should have held up for a while. How long has it been? Since you mentioned hex plugs, it brings to mind that a while back I experienced recurring internal leak failures like this. I replaced carrier seals a couple of times on the same machine. The first time it came back, I thought I had screwed up the seals, so it was a redo. Then it came back again, and deeper investigation showed that the carrier shaft is hollow and threaded for a hex plug, which was machined incorrectly. That was at the beginning of a rash of bad motor carrier shafts from the factory, and we replaced quite a few. If you pull the drive motor, and you look inside the hole where it mounts, you see a splined hollow shaft. This shaft has a smaller hole in the center that has a hex plug inside. That hex plug should be down below the surface and VERY tight. If it protrudes from the end of the shaft, it is one of these bad carrier shaft jobs. The fix is a new shaft. At the dealer, the fix is a new carrier assembly because with labor to swap the shaft and new seals, it's about sixes. This is what they may have done, at $2500 each, and thrown in new, bad carriers. So, I would pull the drive motors and inspect the hex plugs on the carrier shaft before I start replacing carrier seals. If that's the problem, I have a fix for that that does not involve tearing the carrier apart and replacing the shaft. Let us know. Good Luck
I have internal leak on my 863 Bobcat and have isolated problem to the plug on the carrier shaft. It appears factory installed 3/8 pipe plug into a SAE fine thread on shaft. I am not a fan of reinstalling the plug and was looking for a better solution without having to pull carrier shaft. Any assistance would be greatly appreciated. Thanks