First time pulling a Komatsu final drive... what am I getting into?

[DustAndRay]

Done plenty of hydraulic and electrical work but I've never split a final drive on a Komatsu before. Got a PC200-6 that's making a slight grinding from the right side travel motor.
Before I dive in, what should I know? Special tools needed? Any "if I'd known this before I started" advice from guys who've done it?

 

[Lagwagon]

Before you do anything, park up machine, let sit overnight, take the cover plate off the gear side and inspect. Pull the gears out and inspect. Mop oil out at the bottom where any chunks could of settled. If theres no visible damage to gears, including inner housing gears then it's probably the bearings breaking down. How many hours on the final drive?

 

[DustAndRay]

Before you do anything, park up machine, let sit overnight, take the cover plate off the gear side and inspect. Pull the gears out and inspect. Mop oil out at the bottom where any chunks could of settled. If theres no visible damage to gears, including inner housing gears then it's probably the bearings breaking down. How many hours on the final drive?

Thanks for the tip! its about 8,500 hours, likely the original drive. Will pull the cover tomorrow and check the gears and bottom for chunks. Hope it's just bearings going.

 

[John C.]

Is the sprocket seal leaking? Those units last a long time if the oil is changed at the specified intervals. As far as taking one apart it isn't hard. The cover comes off and then the gear sets can be removed. The ring gear is what holds pressure on the main bearings. I don't remember if that has a bolt on bearing cap or a big nut. If there is a big nut you will have to tie the final down somehow. If a cap, there will be shims under it to set preload on the bearings. The seals are large and there is a nack to installing them. Take your time and follow the book.
Good Luck

 

[DustAndRay]

Is the sprocket seal leaking? Those units last a long time if the oil is changed at the specified intervals. As far as taking one apart it isn't hard. The cover comes off and then the gear sets can be removed. The ring gear is what holds pressure on the main bearings. I don't remember if that has a bolt on bearing cap or a big nut. If there is a big nut you will have to tie the final down somehow. If a cap, there will be shims under it to set preload on the bearings. The seals are large and there is a nack to installing them. Take your time and follow the book.
Good Luck

It's not dripping on the ground yet. Thanks John!

 

[Tones]

Before you pull it apart check the oil level, it could be overfull which is caused by the seal on the hydraulic motor leaking and pressuring the planetary hub. That is caused by worn motor internals but more on that later. Check first

 

[DustAndRay]

Pulled the cover today. Gears actually look great, but damn the oil was full of glitter and there's metal shavings sittin at the bottom. Pretty sure the main bearings are toast after 8,500 hours. Gonna order a rebuild kit with new bearings and duo-cone seals. Thanks for all the help guys!

 

[John C.]

What color are the pieces. What I remember was that there are brass thrust washers on each ends of the planet gears and between the planet carriers. Have you left the final drive in the track frame still or pulled it out yet? You will have to pull it all the way out and remove the travel motor to tear the thing apart. They never made kits for rebuilding all the components. I've always had to order each piece at a time.

 

[DustAndRay]

What color are the pieces. What I remember was that there are brass thrust washers on each ends of the planet gears and between the planet carriers. Have you left the final drive in the track frame still or pulled it out yet? You will have to pull it all the way out and remove the travel motor to tear the thing apart. They never made kits for rebuilding all the components. I've always had to order each piece at a time.

They look like silver steel flakes, not really any brass that I could see. Still in the track frame, just popped the cover off to take a peek inside.

 

[Tones]

Stripping the hub while it on the machine is the next best thing if you haven't got a way of securing it in a shop. There's a nut that holds it together can be a mongrel to undo, you'll need good cheater bars.

 

[John C.]

Steel flakes sound a lot like the big roller bearings.

 

[Tones]

Steel flakes sound a lot like the big roller bearings.

Ouch.