What is this bearing?

[chatwithtom]

I pulled the magnet plate out of the bottom of the transmission oil sump in my nortrac 35xtd dozer of 62 hours and this is what I found attached to the magnet.
There no indications of bad operation. What is this destroyed bearing? how did it get completely removed from a shaft it was on? the inside of the bearing did not break apart.
This is in what I believe is called the final transmission. the shift gear box forward of this appears ok.

advice is appreciated. if its just related to PTO, then I will just leave it alone. I don't need PTO. I really don't want to break into this gear box.

Thanks, Tom

 

[piper184]

Not sure what that is from, but in my book it would warrant an immediate tear down. That is a lot of debris to have any any gearbox and open bearing system. Probably lots more damage elsewhere.
YMMV

 

[Bob Rooks]

If it was the pinion bearing you'd know it in a heartbeat.
The cross shaft bearing are tapered roller bearings. That leaves only the live PTO shaft which turns at engine speed - all the time the clutch is engaged. I'd get up in there with a borescope to see what's going on first.

 

[Bob Rooks]

 

[Bob Rooks]

 

[Bob Rooks]

 

[Bob Rooks]

Pulling the top covers off for inspection isn't terribly bad.

 

[Midniteoyl]

Def not good! I 2nd that you need to do a teardown..

 

[Bob Rooks]

What's curious is that the inner race is intact, so I'll speculate that the live (upper, #1) PTO shaft has parted. This is the tang drive PTO that you should not be able to turn with your hand. In fact I think if you reach up in there you'll find a piece of shaft laying around. That said, you still have full use of your 540/720 r/m PTO. At this point no further damage should be expected, pending inspection. You COULD do two thorough kerosene flushes, top up with new oil, and be on your way.

 

[ptsg]

There should be some numbers on that broken bearing. I would look for those, then compare with the parts diagram that Bob Rooks have been sharing. This should give an idea of where this bearing is located on the machine.

 

[chatwithtom]

Thanks all. I will send an inspection camera up there today. I will send my arm up there today. I will inspect for part numbers. I love the idea that its possibly only PTO and only and possibly only 1 speed of PTO. more later.

 

[piper184]

Inspection and flush at a bare minimum. Something moved or broke to release the inner race. Something has been ground up to make all the "fuzzies".
Where did the missing balls go?
What is loose and flopping around that can get into something it shouldn't?
With all that debris in the oil, what did it do to the gears, and more importantly the other bearings?

 

[chatwithtom]

What's curious is that the inner race is intact, so I'll speculate that the live (upper, #1) PTO shaft has parted. This is the tang drive PTO that you should not be able to turn with your hand. In fact I think if you reach up in there you'll find a piece of shaft laying around. That said, you still have full use of your 540/720 r/m PTO. At this point no further damage should be expected, pending inspection. You COULD do two thorough kerosene flushes, top up with new oil, and be on your way.

Thanks Bob. BTW it was you I think that convinced me to buy a mini excavator even After I bought all the material to frame mount my backhoe to my Jinma 354. The mini was the best choice I ever made in tractors.

 

[chatwithtom]

side note. After I identify and/or fix this this and refill. Am I really expected to use 30W oil as manual suggests? Seems more appropriate to use 80-90. It did appear that 30W oil drained out. Thanks

 

[JimRB]

From Bob is the oil guy. https://bobistheoilguy.com/putting-the-simple-back-into-viscosity/

Straight weight oils may or may not have additive packs that may or may not be compatible with the innards of your tractor or excavator system. Some additives attack brass. Others help with rust, others might be extreme pressure additives.

 

[Bob Rooks]

What manual says to use SAE 30 oil? That's inappropriate! Use 85W-90 gear oil in the transmission/bevel gear case (common sump), and 90W-140 gear oil in the final drives. There is no brass in either compartment.

 

[gengine]

For the inner race to still be intact, you either have a broken shaft inside there somewhere, or a bearing was dropped during assembly and left in the bottom. the way the outer race is in pieces, there is a heck of a good chance there are teeth broken out on gears as well.

 

[chatwithtom]

Here is an update. I sent a camera up everywhere I could. see attached. I reached my arm everywhere I could halfway to my elbow. I could not find anything loose. I cleaned it all out with diesel fuel but didn't find anything more debris. No shavings. no more bearings etc. The PTO shaft runs freely when not engaged. It does not turn (not running) at both speeds. Nothing appears out of the ordinary from the view I can see. At this point I am going to add my new 80w90 oil button it up as soon as get a replacement shift stick for the forward transmission and call it done unless someone sees something I am missing. Did the factory drop an extra bearing in this for fun? Thanks for the support. I think that big magnet did an excellent job.

 

[chatwithtom]

What manual says to use SAE 30 oil? That's inappropriate! Use 85W-90 gear oil in the transmission/bevel gear case (common sump), and 90W-140 gear oil in the final drives. There is no brass in either compartment.

from the dozer manual page 48. SAE 30 for transmission. I will ignore the manual for this.

 

[piper184]

WOW!
Totally not what I expected to see after looking at the remains of that bearing!
I can't see how even a dropped bearing from the factory could be that damaged and not have something else destroyed in the process.
At this point one would have to wonder if it wasn't done on purpose just to freak someone (me) out?

In any case, it looks like you have no damage and I see no reason not to clean out the crap and refill with fresh oil, then forgetaboutit.

Lucky you. Except for the scare part....