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?
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.
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.
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.
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 - HeavyEquipmentForums
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.
Howdy all. Bumping this thread up as it's same subject. When the seal around the slew bearing gets damaged by brash pushing up in there, but the bearing is still fine, what do you all reckon about cutting and re-gluing a new seal under there? I seen Mr Logger Wade do this several years ago and have put a link below. If the area was cleaned good and some adhesive dobbed around the house side of the gap, should work for a while wouldn't you think? Cheers gang.
Well all you will be out is the cost of the seal and your time, so I would sure try it. I know @Nige is cringing at this but if it worked and lasted for any amount of time then it would be worth it.
you're a bad man, Oxbow
Sometimes the solution is whatever works for you.........
Lol. Good answer Nige. Could you see a situation where this solution would work for you?
I see a situation where I put a lot of a grease in there and don't worry about it. You can buy a ton of grease for all that effort.
You're right. It doesn't look very right though, at the minute. Greasy... Gluing a seal in there might just be lipstick I suppose.
So, more of the slew ring seal had torn out, and it was attracting a lot of dust...
So cleaned it, measured groove with string, got "SEAL, RING KAB0737" from Case and chopped it to length...
Glued it with shaky hands, slightly out of line...
Stuffed in in there, with glue on the area of the joint. Now let's see how many hours it stays there. The seal was about £36 and it's on a Case CX75.
The thing that damages this seal the most is over greasing. Most excavators it's done at 250hr intervals not daily.
Hi Tones, I'm with you on that. As far as I know, this one was damaged by spending most of it's hours tracking around on brash mats in the forestry, and getting branches jammed up under there constantly. I'm interested and hopeful that it stays intact for a useful amount of time, with it's glue joint.
When the 311B was released, I remember a PIP that required us to install an improved dust seal on a number of 311/312 and 320 machines. We were gluing those in place. The time consuming aspect was cleaning the groove. Good times in the shovel shop.
There are two kinds of rubber strips in the slewing bearing. The one you show above is the outer rubber strip. There is also a large rubber strip inside. If you need to show it to me, I will send you a picture.
Were these seals replaced in situ or did the machine get split in two when you did these? Also, what kind of glue did you use? I glued the joint into the groove using super glue, but didn't go any further round with glue because it wanted to stick before it was in there properly.
Hey UP. I have kind of hijacked this thread; on this Case CX75 parts diagram it showed what looked like identical seals upper (inside) and lower (outer). I changed the outer one. But I'd be interested to see any pictures you have covering this subject. Cheers.
In Situ. Yes, it was a cyanoacrylate, super glue. The procedure called for gluing the entire seal into the groove.
The first picture shows the outer turntable rubber strips, which were applied with a special structural AB adhesive and hammered in with an electric hammer. The red circle in the second picture shows the inner turntable rubber strips. Friendly reminder: The outer rubber strips vary in shape between different models, while the inner rubber strips are the same shape for all models, only varying in length depending on the tonnage.
Thanks for the photos, makes the installation more obvious.
Thanks U P, that's interesting. I looked up AB adhesive and basically that's a two part glue, which may not stick to things quite as quickly as super glue, giving time to push the piece into the groove. On this Case machine the old seal came out without much tugging so I assumed it wasn't glued, but perhaps it was. Thanks for pictures.
Coaldust, do you recall the method by which you got the glued-up seal pushed in there? Cheers.