PC120-6 - oil in the bell housing?

[02Dmax]

Just had a customer call asking how much oil should be in his bell housing. I kinda laughed and said none but he didn't laugh. He has a kid working for him that said it's supposed to be up to the check plug on the side.

I'm not an excavator expert but I've never worked on one that's SUPPOSED to have oil in there. Is there such a thing or is his rear main leaking like I assumed?

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[lantraxco]

Sure looks like it needs oil:

 

[02Dmax]

Ya that does look like a bearing in that diagram.

I guess my next question is it fed by engine oil or should there just be gear oil in there?

Honestly I've never seen such a setup.

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[lantraxco]

Dunno... probably have to get ahold of an owners manual or service manual... or break down and call a Kommie dealer if nobody on here knows

 

[John C.]

It is called a damper case and if you look under the pump and the damper case you will see a hex head that is an O ring plug. That is the level plug. There is a drain plug on the bottom of the bell housing. The thing only take a little over a pint to fill it to the level plug. It take 30 wt. engine oil.

Now the problems come up when people fill the bell housing all the way up to the cap on top or the rear main seal on the engine can leak or the front seal on the hydraulic pump. It can create enough heat to burn the paint off the bell housing. It also burns out out the speed sensor which presents other performance problems for the excavator.

It's about a six hour job to pull the pump, replace the rear main and front pump seals and put it all back together.

 

[02Dmax]

Good to know John C! Thanks for the info.

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[DK88]

Perfect explanation john c

 

[blanchb]

I just had my hydraulic pump rebuilt and the mechanic told me that I needed to add oil to the bell housing after I reinstall the pump. The bell housing didn’t have a drop of oil in it when I removed the pump. The only thing at the bottom of the bell housing was the balls out of my bearing!
Because the bearing came apart the shaft was scared and had to be replaced. I never knew that I had to check the bell housing oil level. But after a $4500.00 rebuild, I will check it more often.
The question I have is what caused it not to have oil in it. It could have leaked out at the drain plug or the seam where the bell housing connects to the engine? It didn’t have a gasket for the bell housing to engine when I removed it and I’m having hard time getting an answer from the service dept on weather it needs a gasket. Or is it just two machined faces that are metal to metal with a gasket sealant?
I attached some pictures.

 

[John C.]

Your photos are not showing the damper? You aren't saying where the ball bearings came from. If there was no oil in the damper case, it was because it wasn't put there after the pump was installed on the engine bell housing. The housings are sealed with RTV sealant. You don't mention that you have an Operation and Maintenance Manual or that you have read through one. Here is a video showing all that you need to know about maintaining these excavators.

Note the part about where to check the oil level in the damper case. It only needs a little less than a quart of oil.

 

[blanchb]

John. Thanks for the reply and the video, it was very helpful.
I bought the machine second hand and the person I bought it from said the engine was just professionally rebuilt before I bought it. I have been owning it since 2006.
I’m not sure what the damper is? The pictures that I posted shows all the parts that came off of it when I took it apart. I also didn’t see the dampener in the parts diagram. My machine is a PC120-6. The model in the video is a PC120-5. Maybe my machine doesn’t have a dampener? I don’t know?
You can see the location of new bearing mounted on the pump. It has the red seal on it. That’s the bearing that failed.

 

[John C.]

I remember it now. It’s like an in line PTO output. The maintenance is the same for both machine models.