Grease leaking from turntable

[Columbo]

Over the past few times I greased and fueled my machine (Cat 311B 8GR00401) I noticed grease leaking from the turntable joint/swing bearing area. This did not appear to be from the bearing as I use red grease in it (and lubricate it sparingly). The grease in the turntable gear cavity is green/black which is what this leaking grease appears to be.

I cleaned up the leaking grease and checked the quantity in the turntable which seemed fine. Today, after running it for about 10-20 hours, the leaking grease is back. On more careful examination it looks like I might be missing an out seal. I cleaned out part of this groove this morning and at the end of the day there is new grease seeping from this area again. In looking at the drawing online, I can’t see how the grease can move from the turntable and out this groove, is that possible? Is solving this problem as simple as buying the new seal from cat and sticking it into the groove or is this repair more involved?

 

[skyking1]

how often do you grease the turntable?
It is in your operating manual, but typically it is several pumps with the house rotated 90 degrees each time, at 250 hour intervals. It is easy to put too much in there and it will take a while to push the old stuff through and see your red grease.
Changing the seal involves changing the bearing. It is a big job. Don't approach this issue from that angle.

 

[Tones]

There should be a seal in there and it's a big job to replace it and requires separating the house from the track frame. Whether to fix or leave alone is pretty much determined by the conditions you're working in. I've seen machines like this were the owners never fixed it but were a bit more conscious about greasing.

 

[Columbo]

Ok, so the consensus is that it’s likely grease from the turntable bearing and not from the tub itself? I certainly have no intention of replacing that bearing, looks like a lot of work!

I typically put 1-2 pumps of grease in the two bearing zerks, spin it around a few times and stop 90 degrees from the first location and put in another 1-2 pumps. I probably do this every 100 hrs? So maybe that’s too much but there is a substantial amount of grease leaking out of this joint. (I probably cleaned 1-2 tubes worth of nasty grease off of here a week ago and now it’s back).

This isn’t a production machine and I just use it around the property on my projects. So, I guess I’ll just keep up with greasing it and hope for the best.

 

[Nige]

If you want to inspect the grease in the swing pinion tub there should be a small rectangular inspection cover in between the base of the boom cylinders secured by four bolts

This thread might give you some tips - https://www.heavyequipmentforums.com/threads/cat-320-bl-swing-gear-and-bearing.92333/

 

[skyking1]

Ok, so the consensus is that it’s likely grease from the turntable bearing and not from the tub itself? I certainly have no intention of replacing that bearing, looks like a lot of work!

I typically put 1-2 pumps of grease in the two bearing zerks, spin it around a few times and stop 90 degrees from the first location and put in another 1-2 pumps. I probably do this every 100 hrs? So maybe that’s too much but there is a substantial amount of grease leaking out of this joint. (I probably cleaned 1-2 tubes worth of nasty grease off of here a week ago and now it’s back).

This isn’t a production machine and I just use it around the property on my projects. So, I guess I’ll just keep up with greasing it and hope for the best.

you only need the tub grease about half way up the gear to keep the gear happy. It builds up in there over time from greasing, and usually you start out with a certain amount. I squeezed 10 tubes onto the gear to get started when I replaced the bearing.
My bearing had enough play in it that I changed it out.
I measured a little over 1/8" at the house to carbody play.
For non-production use I would have tolerated what I had, but the boss was OK with me doing the job.