Swing Motor Leaking on Wheeled Excavator

[Kimo]

Greetings all,
Anyone on here remotely familiar with wheeled excavators? Specifically Cat M series.
I have an M312 that is dumping hydro fluid out through the ring gear as fast as I can put it in.
I'm trying to determine if there is anything besides the swing motor leaking that could push hydraulic fluid directly into the slew. The swivel is not leaking and I can find no visible source for the leak eg; hoses, fittings, etc.

 

[sergioasmi]

may be is damage the reductor inside the gearbox on the swing motor that happpen when something is broken

 

[Kimo]

Anyone have the tear down procedure for reseal on the swing drive? I don't want to take apart any more than I have to.

 

[uffex]

Good day Kimo
The standard practice is to remove the transmission to gain acsess to the bottom seal, be aware that a blocked leak filter or motor transfer can promote such leakage.
If the lower bearing is in trouble check out the wear in the swing ring.
Kind regards
Uffex

 

[DEMLONE70]

Swing motor leaks in the swing drive and this one leaks in slew

 

[DEMLONE70]

Whats the serial number ?

 

[uffex]

Good day
Hydraulic fluid will dilute transmission oil promoting leakage, sorry my English is not up to much either.
Kind regards
Uffex

 

[DEMLONE70]

Swing motor and swing drive work both with hydraulic oil

 

[Kimo]

Whats the serial number ?

6TL01051

 

[Kimo]

It seems that these gears and 208 tiny loose bearings need to come out to get to pinion shaft. This can't be right. Anyone have procedure for disassembling this unit?

 

[heymccall]

It would appear as of the planet gear unit lifts out as a whole. Just a snap ring or two?

 

[Kimo]

Yeah, that's what I thought. However can't get to the snap ring without removing bearings. PITA

 

[heymccall]

I jumped in too quickly.
Invert the housing, remove bolts, separate.

 

[Cmark]

Sorry I'm a bit late to the party here. I've rebuilt two of these things. Here's the skinny;

These are a ZF unit. The swing motor case oil is sealed from the swing box gears in the usual way, but the swing box is force lubricated by hydraulic oil from the main hydraulic system. The main swing pinion runs on two taper roller bearings. The top one is lubricated by the hydraulic oil and the bottom one is grease lubricated. The two bearings are separated by a seal and this will be the seal which has failed in this particular case.

If you haven't done so already you will need to remove the swing box from the machine.

To answer the last question. Yes, to remove the snap ring holding the carrier, the four planet gears, loose rollers and inner races will have to be removed. Getting them back together is another task altogether.

You will need to fabricate or buy a special spanner to remove the pinion lock nuts. If you need it, I can take a picture of the one I made.

 

[Kimo]

Cmark, perfect information, thank you. The planetary gears with the loose bearings is what I was fretting. Separated this out in the field (literally) and bearings scattered everywhere. I bet the guy assembling these things back in the day ended up with Tourette's.

 

[Cmark]

If you buy new bearings, they come pre-assembled with sacrificial retainers to aid assembly. Even so, it's a finicky job and I wouldn't like to attempt it in the field.

The last one I did was only a couple of weeks ago. I considered taking some photos but thought there was no way they could be of use to anyone. C'est la vie.

 

[Cmark]

Actually, I tell a lie. I did take one picture during the teardown. Here it is to prove that I'm not a bullsh!tter.