I recently bought a bobcat 442 with 2700 hrs. As soon as I got it home I started changing all the fluids and filters. I went to change the final drives and one side changed fine, but the other side had no oil in it when I pulled the plug. The plug was wet but no oil. Now I am kicking myself for not checking the oil before I bought it. There was never any sign of leaks so I am wondering where the oil went. Anyway we filled the drives up and the machine tracks fine with no noticeable issues. I am worried about how much damaged may have been caused by running with low/no oil. I am planning on running it a few hours and then changing that side again to see if there is any metal flakes in the oil. Should I remove the final and send it out to have it inspected for damage or just run it and hope for the best? I am wondering if the damage could be repaired now before it become a catastrophic failure. Any thoughts. The cheapest final I can find to replace it is $4000 so having to replace it would be very painful.
I would pull the cover plate off the final and look at the drive pinion and planetaries to see what's going on in there. You may have caught it time. Tom
I'm definitely no expert, but if that happened to me i would change the oil, run it for a bit, then change it again and see if there is any metal in the oil. If there was metal, maybe you could repeat that with a thin oil a couple of times and it could flush any particles out even better. The last guy who serviced my komatsu put thick gear oil in the finals, lucky i checked after 250hrs it's spose to be SAE30 in my machine! So will be changing mine often just in case there is worn metal particles in there. If it was my machine i would't try to fix it before it is broken, from past experiences i have pulled things apart and wasted more time/$ than what the part was worth. But I haven't pulled one apart, maybe its not that hard to have a look inside.
Well after running it a little bit it is very apparent i have a major leak at the face plate. I am guessing the O ring/seal behind the face plate is messed up. Now I have to figure out how to get the face plate off to check for damage and replace the o ring. There appears to be a large snap ring holding it on. Any tips for getting the snap ring out? It doesn't have the small holes that snap ring pliers hook into like on smaller snap rings.
Not familiar with your exact installation, but usually you can either use a pick or small flat bladed screwdriver to lift out an end. Then work your way around, prying the ring out.
Remove the oil plugs, tap the cover in slightly if it will move with a rubber mallet, might give you a little bit more room to work. Not sure if this fits your machine serial number but: https://www.dropbox.com/s/eorqtsz03...-528911001-Above-S-N-528611001-Above.pdf?dl=0
Thanks for the manual link lantraxco. The gear side of the final seems pretty straight forward and not to hard to replace the parts if damaged. Since there is a seal between the gear side and the hydraulic side then i am hoping that any damage would be limited to the gear side at this point since i haven't experienced a complete failure yet. Meaning hopefully we could just replace the seals/bearings and maybe gears on the gear side and the hydraulic side would still be in good shape. Does that seem realistic? I haven't seen the pricing on the gear side parts yet but I did get quoted $3900 for a new drive so hopefully I can repair this one for a lot less than that.
Hi fourwheelinj 1, You may be lucky and it is only an "O" ring on the face plate. Remove clip ring and both plugs then rotate track until there is a sun gear behind each plug hole,wind in a correct sized bolt gently and the faceplate should pop out easily.(Or at least that is the case for Hydash drives). You will then have a good visual on the sun gears and splines. Replace and refill then watch to see if you are getting oil loss,If you are getting it near the drive segment where the two halves rotate, it is probably the duo cone seal that has failed. Start with the easy stuff first............ For reference I just replaced the gears on the out side of a hydash from a 6 tonner and they cost $213 USD for all 4, plus bearings ,duo cone etc Hope this helps. Moss
Thanks for the info moss. My dad and I actually removed the faceplate on Saturday just as you described. It appears we may have gotten lucky. The faceplate o ring was broken which was causing the leak. The inside of the drive looked to be in good shape with no apparent visible damage. Fingers crossed we caught it in time. So I have ordered a new o ring, fill plugs and seals so hopefully I will have it back in action this weekend.