CAT307SSR - swing drive unit questions

Enroute to testing this swing drive to ensure it's not the source of the car-body leak after all (vs. the swivel, now rebuilt), I had to first deal with a broken case-drain fitting atop the drive unit. I've already dealt with the broken case-drain fitting. But there are two barely-recognizable pressure-relief valves that I'd like to replace (heavy, HEAVY rust on the flats made them so irregular that no socket or wrench could be expected to fit, so I had to resort to pipe wrenches). Interior portions look pristine. Since this is a gray-market machine, and I think this level of detail isn't even covered in my Japanese CAT parts book, I'm hoping someone with experience will recognize these as some garden-variety CAT307/308/E80 swing-motor PRVs. I'd appreciate advice [was just reminded I can't post more than four photos - if more needed, I will add in another post.] The other issue - maybe - with this unit is two fingernail-catching gouges in the "racetrack" on the flip side of the swing-drive motor head, where the springs that sit above all pistons ride. See photos below (springs under head, then the "racetrack" on which they ride, and lastly the gouges that bother me). Is this level of wear (and those fingernail-catcher spots where the racetrack runs over two holes, where the springs apparently don't like the lack of support) something to be concerned about? View attachment 3 - under head.JPG Finally, does this design somehow share hydraulic oil with the reduction-gear unit below it, or does that unit have its own gear-oil filler, eg that black cap in photo, with the companion dipstick to right of it? (I mean, what else would those be for?) Reason I'm asking is that some have warned about the swing-drive unit being potentially the /actual/ source of a concealed hyd fluid leak that was exiting from the holes around the swivel - and not necessarily the swivel itself, though it seems the obvious suspect.

Good news is the lenses plate scratches could be plapped flat, the bad news is the outer plate is cactus if it's part of the motor housing.

My 2 cents the thrust pads on your port plates are toast I would guess new port plate and barrel lapped at bare minimum

Tones said: Good news is the lenses plate scratches could be plapped flat, the bad news is the outer plate is cactus if it's part of the motor housing. Click to expand... Thanks, but I'm struggling to interpret the typos...or lingo...that I don't know (lenses plate, plapped, cactus = ?)

pittsburgh cat man said: My 2 cents the thrust pads on your port plates are toast I would guess new port plate and barrel lapped at bare minimum Click to expand... Thanks - can you confirm the port plate is the gold-colored affair under the head, while the barrel is the mating component (not shown - don't know why that photo didn't show up, but attaching below) that's slightly submerged in fluid, surrounded by springs? Also is there any way there could be a hydraulic oil leak from the swing motor that I would not readily see within this well, but that could make its way into the space between car-body and the mounting plate above it? I'd think it'd be present in the gear oil, or even overflowing from the dipstick or filler port if that were happening. I'm hoping to at least cross THAT off my list of potential problems... View attachment 3 - under head.JPG

yes the gold color plate is the port plate The springs are for the swing brake the scratches you marked is where the springs ride no biggie if you look in your Japanese parts book under frame and body then drive group swing I think you will find what your looking for. It could be possible but you would have to have a couple bad seals

pittsburgh cat man said: yes the gold color plate is the port plate The springs are for the swing brake the scratches you marked is where the springs ride no biggie if you look in your Japanese parts book under frame and body then drive group swing I think you will find what your looking for. It could be possible but you would have to have a couple bad seals Click to expand... AH, the swing brake - I was wondering why so many springs...that's a relief. Since it's a gray-market machine, the only documentation I have (parts book) is all in Japanese language, with no usable index. And unless there's a whole different section where there's a more detailed breakdown that I've not paged through yet, it's like the swing drive as a unit is treated as a single part number! Only the externally-attached components seem to be given ID/part numbers. I'd like to replace the pressure-relief valves, but no clue what their P/Ns would be, nor even their pressure rating - same for the internal components like the port plate and barrel you mentioned. Are those last two items typically just honed to remove scratches and burrs during a rebuild? (No problem with change in clearances?)

look at av spares 307 a it may help with a diagram also check some of the parts for a part number one thing I noticed is the barrel convex and port plate concave that makes it tuff to lap might be able to get a or barrel and a new port plate

Thanks again! I'm checking with a local hydraulics machine shop to see if this is something they're familiar with/capable of reworking. AVspare.com - gotta spend some time to navigate to what I'm after, I guess - it's a little bewildering at first.

Apologies for the typos. The Gold coloured part I've always known as a lense plate and have lapped them in the past if they were scratched but not gouged. Hope this helps with the lingo and typos.

Pants said: Since it's a gray-market machine, the only documentation I have (parts book) is all in Japanese language, with no usable index Click to expand... Send me what you have through a PM if it's under 10Mb in size.

Pants said: Thanks again! I'm checking with a local hydraulics machine shop to see if this is something they're familiar with/capable of reworking. AVspare.com - gotta spend some time to navigate to what I'm after, I guess - it's a little bewildering at first. Click to expand... I made some progress with that site just now...seems like my drive is interchangeable with 307B and E70B, so that's something...but the PRV p/n comes back with "This part has been indirectly replaced. Please consult your dealer for product replacement options" (indirectly?) and the plate with "discontinued," so not real hopeful there.

LCA078 said: Send me what you have through a PM if it's under 10Mb in size. Click to expand... Looks like I broke through the previous "no-drawing" problem, so I've got some part numbers, but they don't seem to lead anywhere good: Port plate 5I 9307 Barrel 5I 9320 "Valve AS" 5I 9331 (I think these would be the two PRVs built into the swing motor head to damp the side-to-side motion after completing a swing.) Were you thinking you'd be able to help with the language, or general interpretation of the minimalist descriptions in such a parts book? Or the parts themselves? I'm hoping the local shop will be able to lap the plate and barrel - waiting to hear back from them. Thanks - Dave

Pants said: Were you thinking you'd be able to help with the language, or general interpretation of the minimalist descriptions in such a parts book? Or the parts themselves? Click to expand... I've had luck with using AI to translate documents in the past so I was going to give it a whirl. It's not perfect but definitely better than looking at little squiggles and scratching your head.