Cat 320 BL Swing Gear and Bearing

[BrianGrenier]

Hi Experts,
Could I get an opinion on this picture?

On this 9JS00308 Cat 320 BL 138 FWHP, the Swing Gear and Bearing seems to "catch" and the structure will not swing after working in some positions, especially after working at a diagonal to the tracks and shaking the machine can get it to swing again.

I searched the forums and saw helpful posts,@John C. had a good video on one machine.

The attached picture is an inspection plate to the swing gear.

The manual states to "Add 5P-0960 Multipurpose Grease to the swing gear and bearing after it has been installed. Refer to the "Operation & Maintenance Manual" for lubricating the swing gear and bearing at specific service intervals." I was not able to locate the section specified above.

A Cat maintenance video said several gallons of swing gear grease should be in that well. I may be mistaken.

So, what can you see with the picture? What grease and quantity should be in that well?

 

[heymccall]

Grease looks fine at what is a normal level.

Is there oil in the swing gear box?

 

[BrianGrenier]

This should be the swing gear dipstick level which is just below Full and above Add

 

[heymccall]

If optioned, there is a fine swing rocker switch. If you activate that, does the swing still jam?
Mind you, that switch will disable the swing brake, and, if working on a slope, the house will not stop when turning.

 

[63 caveman]

Pull the swing gear and check the planetary, that is if you know the brake is releasing.

 

[Cmark]

That grease looks pretty emulsified. Don't discount the possibility that you may have ice in there.

 

[Bluox]

You might get a flashlite and have someone slowly swing the machine while you watch for teeth damage.
If the stop point is in the same spot likely the swing gear.
Bob

 

[uffex]

Good day
If it locks once every 360 most probably indicates damage (Broken slew ring tooth) if less come back to the transmission. Suggest you swing the locking position and pull the swing box.
Kind regards
Uffex

 

[BrianGrenier]

The temperature warmed up a bit today at least about freezing so I was able to run the equipment. First I installed a zerk that was apparently missing, but grease only escaped from just below it even with a poorly fitting plug (another zerk wouldn't fit and I didn't find a proper threaded plug). So, I squirted half a tube of lithium / 5% moly grease through the port the inspection plate covers. Running for a while and it didn't seem to lock up and I didn't get a chance to see about the fine swing. So maybe it's just lack of grease. Ice would have also been a possibility but it would do it in warmer weather too.

Obviously, I haven't been greasing that part.

And I don't know about the zerk ports, maybe add a good threaded plug on the underside one so that I can actually shoot grease through the new zerk. See attached. Thanks!!

 

[heymccall]

Your "open" is supposed to be a 90° fitting, to which a steel line is attached. That steel line goes CW around the unit to exactly 180°, and attaches to a 90° fitting threaded into the unit.
Your "zerk" arrow greases the back side via steel piping.
Below your "zerk" is another. That is for greasing the front side.

 

[BrianGrenier]

That's very good to know and very generous of you to post that.
All metric fittings too, I presume.

 

[BrianGrenier]

It's finally warming up enough to take a look at this swing gear. I took a picture of what I was getting out of the well that's accessed from the small port under the house. I got maybe 2 gallons of tan colored goop with big chunks of ice. That's what the picture is trying to show.
The big chunks of ice has mostly been removed and since it was in the 40s today I was able to mop up the water that was remaining in there.
Thanks for the diagram @heymccall. Forgive me cuz I'm kind of ignorant and maybe I'm ready for the dang fool comments but, I see what I call the zerk isn't made to take grease into the port, there's no opening there to shoot grease at the ring, but it looks like the grease line is designed to go around to the AA on the diagram. I can't locate any missing connection on that opposite side of BB. It seems my option is to keep the port open and pump as much grease as I can along the gear ring as I swing the machine around. Is that maybe the best option or keep trying to locate the port for where the grease is supposed to flow into the ring.
So just to clarify, it looks like the problem with it swinging was ice chunks and somehow water getting into that well and creating the breakdown of the grease and making ice cubes.

 

[John Shipp]

As heymccall says, that zerk in the square block is ( or was) a fitting to group service points together for ease of maintenance, it would have originally had a steel pipe connected and running round to the other side to remotely grease that side of the slew bearing. Most machines have 2 or 3 grease points to the slew bearing, you don't want to over grease those ones, just 1 or 2 shots on each zerk and not every day like the ones on the bucket linkage etc. If it's coming out past the rubber seal you can see just underneath it's too much.

The inspection port into what you call the well, if you've successfully drained this by removing the plug underneath you have done a great job. This can be re filled using a bulk bucket of grease and some kind of scoop or spoon. If you've got grease cartridges, use the base of the grease gun without the pump screwed on- load the cartridge in keeping the plunger locked out, jam it in the port so it's wedged somehow, then release the plunger and it'll dump the tube in there pretty quick. Dump a few tubes in, then rotate a few degrees, keep dumping them in until you fill the whole area. Your machine manual should tell you the depth of grease you need, usually about 3/8" to 1/2" I guess. You'll need a box or two of cartridges if you do it that way.
You may want to check that the rubber seal around the rotary union is not torn, if water is getting in to the slew gear. Often the area around the rotary and inspection port gets chocked up with dirt and rain water pools up on top, seeps past the rotary rubber seal.

 

[63 caveman]

Also clean out the leaves, twigs, and crap out around the swing motor and park the machine with the boom side down a bit so the rain/snow water can run out instead of finding it's way in the slew bath.
Good thing you waited for some warmer weather to look into it, big ice chunks can do some serious damage. Good job!

 

[Cmark]

As noted above, the grease for the swing gear and the grease for the bearing are two different things. The bearing is lubricated by the external grease fittings. The swing gear is lubricated by the grease in the pan - fill once and that should be it, unless you have a problem like this.

You need to fix where the water is getting in. There's a good chance that the rubber boot around the swivel has failed.

 

[John C.]

It's an old machine so the water probably got in there over a period of time measured in years. Have you checked the free play in the swing bearing?

 

[BrianGrenier]

@John C. I'll need to look in the manual to see how to check the free play in the bearing.

Also, there's an apparent drain plug, but this stuff is not gonna come out that way as it's too thick. Barehanded scoop removal is what I have done so far with only one complete 360⁰ turn, stopping maybe every 15⁰ to scoop.

There's a heavy skid plate on the underside of the swivel.

There's still a lot of contaminated, emulsified water and grease.

Is filling with gear oil, swinging that around, draining and then 5% moly grease a way to go?

Or just circle around one more time, trying to mop up the mess, then place about two gallons of grease in the top inspection "port"?

Mornings are still cold, so it's a late eve project, not hard, but I don't want to do it again.

Here's a video. A grease line was probably deleted early on, or wasn't installed with this machine as it spends most of it's time in brush and slash. When I got the machine there were no grease fittings on that square port.

 

[Nige]

Is filling with gear oil, swinging that around, draining and then 5% moly grease a way to go?

If you make a good job of cleaning out the old grease by hand that should do fine. It may take a couple of circutis. As CMark mentioned, while youhave the tub empty of grease that's the right time to make sure that the seal is in good condition.

Definitely not moly grease for a swing tub application. A regular lithium-based EP2 grease will be fine.

Do you have any way of warming the grease before you put it in through the hole.? That way it would spread & level in the tub far easier/faster. You will still have to dump grease in the hole, swing a few degrees, dump more grease, etc, etc. Repeat as required until you have gone a full 360. I wouldn't try to fill it up all at once. It might be better left a bit llow and then add grease a bit at a time in any low spots until the level is correct. When the level is right the swing pinion will be just touching the surface of the grease and will make a series of "swirls" in it that somewhat resemble what you would see when whipping cream with a food processor.

Regarding your video. it was hard to see but there were a couple of areas in the swing bearing that looked like they could be plugs where a grease connection once was. Unfortunately the video didn't get close enough or pause long enough to see what they were. Below is an image from your video. What are in the two circles.?



Below is what the steel grease lines should look like. As they are missing on your machine the best you can do is look for some plugs on your machine where the elbow fitting (circled) would have been screwed into the swing bearing.

 

[Nige]

All metric fittings too, I presume.

Actually no. The 5K9243 elbow is brass.
It has a 1/8" male NPTF 27 TPI thread on the end that screws into the swing bearing and a 7/16" SAE J512 24 TPI female 45-deg inverted flare on the end where the grease line fitting connects.

Attached both parts of the Swing bearing & grease line parts list. It might help you to make more sense of it all.

 

[John C.]

The video link below shows how to check the play in the swing bearing.

There are a plate underneath the carbody in the cavity where you find the swivel. You machine may have a swivel guard which is just two big plates that bolt into the circle hole below the swivel. You can remove that plate and grease and water will drain. If you put the boom in the middle of the track frame when the idlers are in front, the drain hole will be in the back. It takes a big pan to catch the junk that falls out and makes a mess but is faster and easier than digging the junk out by hand. I liked to park the machine on a slope so that drain is on the down hill side. If you have help one can slowly turn the house while you hold some kind of scraper in the hole to push the grease to the drain. In all truth that usually only gets cleaned when someone changes the swing bearing or has to pull the swing machinery to replace the pinion seal.