Clutch Repair Kama 554

[greg_g]

The bearing from Chip was loose, because it's essentially stored dry. All that slop is removed once you pack it properly. I'm guessing the NAPA bearing is probably sealed. Comparing a (dry) greasable bearing to a sealed bearing is apples and oranges.

The larger inside surface area does make the NAPA bearing appear the preferred choice. But it remains to be seen how well it's slightly larger ID grips your nicely shined up sliding seat.

//greg//

 

[3RRL]

You saw the grease fitting I installed on the TOB Seat.
My next goal was to have a couple places where grease could find it's way to the small .020" radial gap between the bearing race and shield. I set the mill head on 15 degrees and picked a point on the TOB Seat where the bearing race hits that ledge. I drilled 3 holes on the top side only. The holes found their way into the grease cavity inside the Seat as you can see in these photos.



With the TOB pressed onto the Seat, part of the holes are exposed to the outer edge of the bearing race and also right to the small gap between the race and shield. If you look closely in second photo, there are 3 small "nicks" which are the holes in that ledge. They barely break through to the OD of the Seat itself. But if you look inside the Seat, you can see the light coming in there. I shined a flashlight onto the race and shield so you could see the holes from inside the Seat.



I figure if I can get a small amount of grease to that gap, as the bearing turns it will "leach" grease into it and the grease will eventually migrate onto the ball bearings. It's a way to keep the Seat and bearing lubed.
As long as I don't over grease it, it should work great.

 

[greg_g]

I see where you want to go with that migration theory - but can only visualize it working in conjunction with a greaseable bearing, if at all. If however - you end up using a sealed NAPA bearing, doesn't that kinda throw the migration part out the window? Or am I wrong about the NAPA bearing being a sealed type ?

//greg//

 

[3RRL]

To make sure that it was all going to work as I planned, I had to assemble the Seat and grease fittings onto the Support Tube inside the bell housing. Instead of the knot, I tightened the grease hose into a better position without the knot. With both ends fastened, it should stay that way.

I hand packed the grease groove best I could and slid the Seat onto the Support Tube. Then, after attaching the spring, I slid it back and forth and wiped any excess grease off. This was so I could visually inspect where the grease was going. I was hoping I could "feel" when the grease cavity was full and after that, see how many pumps it takes to get some grease out those holes. I also wanted to confirm the grease would go out those holes before finding it's way out of the slight clearance between the sliding Seat and Support Tube.



The result was great.
I got a small grease gun that I will only use to lube the TOB. I could "feel" when the cavity got filled up because there was more resistance to the grease gun. I checked with a mirror at this point and no grease had come out the holes nor between the sliding Seat and Support Tube. Then I pumped 2 more times and saw grease starting to come out of the 3 holes right by the race and shield. The last photo has a small mirror which shows the back of the TOB and you can see the small gobs of grease just starting to come out. You can also see no grease has come out between the sliding Seat and Support Tube.

With the Zerk fitting easily accessible from the outside, I'll check it in one month ... add only if I can feel it go easily. If none is needed, I'll check it again the following month and so on until it needs more lube.
Maybe it'll never need any more lube, but if it does, I'll know it.
Rob-

 

[greg_g]

Then I pumped 2 more times and saw grease starting to come out of the 3 holes right by the race and shield. The last photo has a small mirror which shows the back of the TOB and you can see the small gobs of grease just starting to come out.

Disregard my previous post. Now that I've seen those last photos, I'm completely mystified why anybody would want to grease a bearing seat. Mine managed to spin on its seat - destroying it actually - without the help of any lubrication whatsoever.

//greg//

 

[3RRL]

Hi Greg,
The Napa bearing has a .001" press fit. I couldn't force it on by hand ... not even started. I had to use my hydraulic press to seat it and it's tight. The bearing is not a perfectly sealed bearing with actual bearing seals like the ones I use in my injection molds. Much like the OEM bearing, it has a ball bearing cage or shield which has a .020" radial gap between it and the bearing race. I could see the grease that was inside it through the gap.
Look at the photos.

The replacement bearing I got from Chip was not dry, it was also greased. Even packing it with a bearing packer, the race would still move in relation to the shield. You can squish the grease around by moving the race axially. You'd have to see it. If you want, I can send it to you and you can pack it and see what I mean.

 

[greg_g]

If you want, I can send it to you and you can pack it and see what I mean.

Naw, send it back to Chip. It may be the one I sent back to him last year. It had no grease hole AND was sloppy after packing. The other three I got from him were ok. The two spares in the basement packed so tight I can only turn them by hand with great effort.

The one I put in my TS354C last year packed so tight that it wouldn't even spin right away. I momentarily thought I'd done something wrong putting the tractor back together, but within a few seconds the whining went away. It just took a while for enough heat to be generated to thin out all the grease I'd packed in there. No problems since.

Good luck with the NAPA bearing. It would be nice to have the option of a viable aftermarket crossover bearing. But I still maintain reservations about greasing a bearing seat on purpose.

//greg//

 

[3RRL]

Disregard my previous post. Now that I've seen those last photos, I'm completely mystified why anybody would want to grease a bearing seat. Mine managed to spin on its seat - destroying it actually - without the help of any lubrication whatsoever.

//greg//

I see from this reply and your last one that you have no idea what I've done with the lubrication holes.
It's like I spend all this time explaining it and you manage to turn it into lubing the seat for the bearing race.

When I say TOB Seat, with a capital "S", that is what the manual calls the sliding vessel that carries the Throw out bearing. It slides on the "Support Tube" or "Seat Support". It's NOT the same seat where the bearing "race" presses onto as in what you refer to. That's a press fit and you can't lube it because there is negative room between the two. I am NOT lubing it. The holes are above the race near or at the level of the shield and minutely exposed ball bearings, all of which are above the seat you refer to.

 

[GuglioLS]

Hey Rob,

As usual nice machine work customizing the bearing carrier with those 15* grease channel holes. Perhaps consider placing an O-ring around the back of the bearing and over the holes? Maybe that would help force grease into that .02 gap into the bearing race and slow / reduce the likelihood of grease slinging out? Maybe worth a try?

From what you describe the replacement bearing is rather sloppy (bearings too small for a tight fit. All the grease in the world will not take up the gap. So I can fully understand why you would not take a chance using that one. The NAPA bearing seems to be the ticket.

I sure do look forward to seeing your two tractor halves going back together. Seems like your almost ready for that, right?

Larry

 

[tommu56]

Hi Greg,
The Nap bearing has a .001" press fit. I couldn't force it on by hand ... not even started. I had to use my hydraulic press to seat it and it's tight. The bearing is not a perfectly sealed bearing with actual bearing seals like the ones I use in my injection molds. Much like the OEM bearing, it has a ball bearing cage or shield which has a .020" radial gap between it and the bearing race. I could see the grease that was inside it through the gap.
Look at the photos.

The replacement bearing I got from Chip was not dry, it was also greased. Even packing it with a bearing packer, the race would still move in relation to the shield. You can squish the grease around by moving the race axially. You'd have to see it. If you want, I can send it to you and you can pack it and see what I mean.

Rob the bearing with the gap is what we call shielded bearing as oppose to the sealed with the rubber lip seal verses open with nothing

tom