580C Transaxle- whats on my gears?

[DirtyHoe]

My 580C has sat for about a year. I do start it, but have not been driving it. I started working on the brakes today and the cross shaft was stuck. So I took the lid off the transaxle so I could press the shaft out. I was shocked to find what I would call small steel filings mostly on the largest bull gears, but in other places too. It's in the same place on both gears. About 30% of the gears toward the steering wheel. It's definitely 100% magnetic. It wipes off using a finger and a rag. But very odd that it looks like it was dropped down from above or sprinkled onto the gears. The underside of the lid has the same debris. I don't think condensation could cause this? The breather needs to be replaced as it appears to be mostly clogged. I haven't drained the oil which looks OK, but needs to be changed. I have never been in the transaxle or serviced it. I did drag a magnet around the bottom of the casting and found some much smaller debris(more like metal paste), but no large pieces. The gears look in great condition otherwise. Any ideas of what is going on here? What should be my next steps?

Steve

 

[Bumpsteer]

Rust never sleeps...

Ed

 

[DirtyHoe]

Some more pictures:

 

[hosspuller]

Dendrites or rust crystals dropping from the cover. Note the crystals growing on the cover. Remember they're growing in 3d. When they get too big or too long to be self supporting they fall. Sprinkling your gears. Note they start from the gasket edges of the cover. Likely, where air /moisture enter the gearcase from air/temperature changes.

 

[DirtyHoe]

Great explanation. Thanks! I think the biggest culprit was a clogged breather that probably trapped the moisture inside the case.
What is the best way to get this cleaned up? I would imagine this stuff could do some damage to the bearings? My plan was to drain the oil and clean it up all the debris with a magnet and a rag. Do I need to flush out the case with a solvent before I replace the oil?
I'm wondering if this is the original transaxle. It's the only red paint I have found on the entire machine.

Happy 4th,
Steve

 

[Delmer]

Clogged breather had nothing to do with the condensation. If you want to avoid condensation, you'll have to store it inside, or hundreds of miles East of your location. A dessicant breather would help, wouldn't have to be complicated, even a piece of dry wood with the right container will keep the humidity down. There used to be a silica gel cat litter, or other silica gels that work great as dessicants.

I don't think much of it fell off the cover, but could be, hard to tell from a pic. Rust expands to many times the volume of the original steel, so that could have come from the cover. Or it could have started on whatever defect was on the surface of the gear or the scratch on the cotter pin. You never would have noticed without taking the cover off, I doubt it would hurt anything to run it, the rust will settle out soon enough.

 

[mitch504]

Yeah, the most I would do is wipe everything off. If you can't move it periodically, spray rust preventer on the unoiled surfaces.

 

[Tinkerer]

A gallon of diesel fuel in a 2 gallon plastic garden sprayer may do wonders to flush it.
After the oil is drained.
The red paint is quite common in gear cases and motor blocks.

 

[Delmer]

Tinkerer is probably right, you could even use the oil itself to flush it. Drain into a clean bucket, let it settle, flush into another clean bucket, let settle, repeat until satisfied. Let it settle overnight on top of the cab, siphon most of it back in, and add a gallon or two of new oil.

 

[Coy Lancaster]

After all that you will still have rust in transaxle. But be sure and check your case breather it needs to be clean so moisture will escape some what. Also check shifter boot for splits and loose fitting around shifter. That's where a lot of water gets into transaxle.

 

[DirtyHoe]

Delmer- Good point, I would have never known had I not removed the cover. I'm guessing there is a lot worse ones out there the owner didn't know about.
I sandblasted the cover and will epoxy paint the cover since I'm painting other parts anyway. It looks like the cover was the food for the rust. The cool-looking dendrite pattern is engraved into the cover. The paint won't stop condensation but should stop the rust from falling onto the innards. The good news is there was enough oil on the gears that they are wiping clean with not rusty pits.
Tinkerer- There is a fair amount of sludge at the bottom of the casting. I will either spray or wipe it down with some solvent or diesel.
Coy- I ordered a new breather.

Steve

 

[DirtyHoe]

The cover definitely lost some metal. It's a cool looking pattern for being so destructive.
Here it is sandblasted:

 

[DirtyHoe]

I sprayed epoxy primer and paint on the lid. I've been using PPG Delfleet Essential single stage paint system.
The frustrating part it makes all the old rusty surrounding parts look awful.

 

[DirtyHoe]

On a different thread, I rebuilt all the brake parts. Today I planned on replacing the side gear seals. I drained the oil. There was maybe a half cup of water that came out first, but overall the oil looked good. There was just normal wear paste at the bottom of the casting. So after reading a few threads on the transaxle I figured I would check the backlash(tons of it) between the ring gear and pinion gear while I had the cover off.

When I grabbed the pinion shaft to keep it from rotating I noticed a lot of end play(at least .018). Then I checked the side gears. The whole assembly(both side gears and the differential center wheel) have about .02 end play pushing from one side and using a dial indicator on the other side. What I don't understand is the bearing and gears look in great shape. No significant visible gear wear. How did it survive being this loose?

Questions:
How did all of this get loose?
Does this all need to come apart to fix it?
I don't think the large square shims(side gear plate) alone will get rid of this much end play. Did the thrust washers between the side gears wear out? The pinion gears all have clearance too.

Thanks for the help,
Steve

 

[Coy Lancaster]

Do you have a service manual?

 

[DirtyHoe]

Yes, I have all of the manuals. I have read as much as I could find on the topic. This is a big job and I don't want to take any more apart than I have to.

I'm beginning to wonder if this is the original transaxle. The paint is a different color and there is some white chalk written numbers on one side. For as loose as it is it doesn't look worn and 40 years old. Not that it matters at this point.

I just noticed both rear axles have about 1/16" of end play and one leaking axle seal on the right side. So it looks like the castle nuts were not tight enough.

Since nothing appears to be in tolerance, I'm guessing the odds are the main shaft and gears are not proper either?

I'm still scratching my head as to why things look in great shape in terms of wear and tear? Most with loose fitting parts have a lot of wear and chipped gear teeth. I'm lucky in that respect.


Steve

 

[Delmer]

We started all of this because there was rust falling from the top cover, right? put it all back together, MAYBE replace the seal if you can easily. You'll never wear this thing out if you're 1% as careful operating it as you are taking care of it.

 

[stinky64]

Yes, the side thrust washers do wear,and disintegrate over time..when I rebuilt my transaxle the left side washer was almost gone, and all the "shrapnel" from the washer also took out the spider gears that live in the center wheel...I've read in other posts that the left side is the load side and breaks down more often....You have the floor out and the top cover off that's the hard part..If you're going to do the thrust washers, you're going to have pull the bull gears/axles, why not just drop the transaxle and move machine forward w/the hoe...It's actually a lot easier than it sounds and sooo much easier to work on standing over it than under it...As far as the endplay in the counter/pinion shaft, if all the bearings/gears look good you can probably pull the front cover and retorque the locknut. After all the quality repairs you have done on that machine why not do a one and done on the transaxle as well...When I did mine I replaced all seals,bearings,races spider gears/pins, thrust washers shims..no major gears, got lucky there, ordered all the parts from tractor stuff/e-backhoe parts, all came in one box 4 days after I ordered..Final cost about $1000. but if your gears and bearings are useable, much cheaper.... Hmmmmm what to do

 

[DirtyHoe]

Delmer,
Actually, this started out as a brake job and leaky seal repair. I do take care of my stuff, but I run my tools and equipment pretty hard. If I was not going to keep it I would probably just call it a day. Between keeping it and being a little OCD I'm going to fix it. The thought of diving into my dirt piles with that much slop makes me nervous. It will be a bigger and more costly job later. Plus I enjoy learning and doing the work. Knowing what I know now I would have bought a newer lower hour machine for more money.

Stinky64- I'm just going to put things back to specification and replace the seals. Replace the thrust washers if they are damaged. Bearings and gears look great.

Steve

 

[Tinkerer]

Good plan DirtyHoe.
A supposedly low hour machine can sometimes be a money pit.