Transmission Experts: How does this pinion bearing look?

[19-VW-74]

I'm in the middle of overhauling a double side cover IRS trans that had some main shaft bearing noise.

When I pulled the diff out, the large pinion bearing retaining nut was hand tight. I removed it by hand.

When I disassembled the pinion shaft, the small pinion retaining nut was also loose. There were some chisel marks on the small nut as if it was tightened without the correct tool at some point.

The ring and pinion are in excellent shape with no pitting to speak of.

The bearing turns smoothly, if a little noisy when clean and dry.

There was no detectable play in the bearing when assembled.

Should it be replaced?

I pressed off the pinion bearing and cleaned it and this is what it looks like:


Pinion side:

Gearbox Side:

Rollers:

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-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[VW_Jimbo]

Looks bad to me. I would change it. Too cheap of a part to have to go back and replace it!
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

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I wouldn’t say it was destroyed, but it definitely has some wear to it. For as much as you have to take apart to access it, I would replace it. Throwing something together for a woods buggy would be one thing, but if you are wanting the best reliability, replace it.

[19-VW-74]

The bearing # is marked 524810D. This is nearly impossible to find a replacement. Is the FAG 531068A bearing interchangeable?
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-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[[email protected]]

[Lingwendil]

I would reach out to user mcmscott- he has lot's of transaxle parts, and good leads on what you may need to do. He builds them for a living and is very knowledgeable and helpful.
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73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

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[sb001]

[Bruce]

[19-VW-74]

I'm able to find the 531068A bearing for around $120-150.

Is this a direct replacement for the 524810D? (Beyond setting the pinion depth, of course)
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-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[74 Thing]

https://weddleindustries.com/products/113-311-219-A/113-311-219-A

Call Weddle

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[19-VW-74]

The bearing had identical rollers, with both inner races marked 524810D. There was no spacer (or even pinion shims, for that matter). I'll order the 531068A bearing.

Thanks for the information, gkeeton.
_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[[email protected]]

[19-VW-74]

I've looked and looked. Gone over the whole thing with a fine tooth comb. No shim to be found. I may have to start moving my bench around to see if it fell.

Is it possible that my transaxle had no shim after manufacturing?
My pinion shaft is marked for r = 0.28mm.
_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[VW_Jimbo]

[Bruce]

[Bruce]

I think your pinion bearing may be ok to use. To know for sure requires more inspection.

To judge the outer race, only look at the threaded side. The side with the flange never has any load on it, so it is always better than the threaded side. Does yours have a notch in the threads to stake the nut after it's tightened? If so, this is always oriented at the 9 o'clock position as viewed from the diff side.

Think about the load applied to the bearing. The pinion teeth are pushing down on the ring gear, so that means the pinion shaft is pushing up on the bearing's outer race. There is also a slight amount of force pushing the side cover out of the case. The reaction force on the pinion bearing from that is then towards 3 o'clock. But this side force is very little compared to the force pushing up. What all this means is that the main force on the outer race is pushing at about 12:30 to 1 o'clock. This is where you look.
If there isn't a notch to indicate how the outer race was installed, simply judge the worst part of the race. That will be at about 1 o'clock.

Post pics.

When I reuse a bearing, I always install it so that the notch for the nut is at 3 o'clock. Now the bearing is pushing against the better part of the race.

You can spend a minute or two with some 600 grit sandpaper to see how it looks. It may improve a lot.

Next is to inspect the inner races of the two bearings. After washing them in solvent then drying them with compressed air, I use an eye loupe to look in between the rollers. I have to have a bright light on the other side to get enough light in there. Slowly turn the inner race while holding the cage steady and look at the race for pitting.

Above I told you how it's pointless to look at the flanged side of the bearing. The reason for that is why the inner race that was on the 1st gear side will be in better condition than the bearing that was on the diff side. If both inner races have no pitting, and the outer race looks good, I install the bearings opposite of the way they were. Put the one that was next to the pinion gear on the 1st gear side.
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[19-VW-74]

[Bruce]

Now look at the inner race of the two bearings. The one originally by the pinion gear should be worse. These races are usually in worse shape than the outer race, so looking at them is more important.

Two things tell me your gearbox has been rebuilt in the past. The etched markings on the outer race are different from what FAG used in the 70s. It tells me someone put a new FAG pinion bearing in it last time it was rebuilt.
The nut you describe sounds like the SKF nut. VW never mixed them at the factory. There's absolutely no harm in mixing them today. Since you can't stake the nut, I recommend a microscopic amount of Loctite. For that location, I use Loctite 290. This Loctite is intended to be applied on assembled fasteners and will wick into the threads. It holds the nut well, but after applying heat, you can still remove it. Do not slather on huge quantities of "forever" loctite, it isn't needed there, and one day someone might want to take it apart. I put a single drop onto the tip of my xacto knife, then touch it to the gap between the nut and bearing race. I do that in about 8-10 locations.
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