R380 5th gear noise

[vnx205]

On the way back from Perth, 5th gear developed a bit of a noise. I assumed it was the bearing at the end of the layshaft in the extension. Other gears were quiet. That was the problem at 156,000, so at 315,000, I thought it was the same issue.

However it is the bearing in the extension on the main shaft. What puzzles me is that the inner race is badly pitted about halfway round and appears perfect on the rest of the circumference. I would have expected the damage to go all the way around.

What would cause that wear pattern? Does it indicate some other problem?

I also don't understand why the other gears could be so quiet if the worn bearing was on the main shaft. Can anyone explain why?

The layshaft bearing that I fitted previously appears perfect, but I thought it might be wise to replace it while I have things apart. after all it has done about 160,000. Good idea?

I believe that replacing the oil pump is a good idea at this mileage. Is that recommended?

Although the original clutch seems OK, I am also assuming that replacing it might save a lot of work some time in the next few years. Does that sound right?

I also need to replace the O rings on the transfer case intermediate shaft.

[roverrescue]

Did you notice the noise more on coast than under power in 5th?
Only thing I can think of why it was noisy in 5th but not lower gears is that on coast it is being over driven by 5th? So any float might show up as noise.

What lube are you using?

My old disco did 340,oookm on existing gear bag and tdi defender I changed the box out at 250 ish but only because I had found a sub 75k box for silly money. Neither the high mileage boxes threw a bearing ?

S

[vnx205]

Almost no noise with very light throttle. Noise increased as throttle increased.

I use Penrite Trans Gear 75W-80 semi synth.

[vnx205]

This is what one side looks like. The other side is almost perfect.
152408

Something else that isn't quite what I would have expected is that I can only find one roller with significant damage. That roller is only like that on one side. The others have only tiny marks.
152409

[Old Farang]

This is what one side looks like. The other side is almost perfect.
152408

Something else that isn't quite what I would have expected is that I can only find one roller with significant damage. That roller is only like that on one side. The others have only tiny marks.
152409
That appears to be a from of "brinelling". There are several things that may cause it. It could just be a poor quality bearing where the hardening process is faulty. Bearings stored before use in a situation where there is a small but intense vibration and the bearing has been stored "upright" or on edge. This can also happen after the bearing has been installed where the equipment itself is subject to vibration. A big problem on ships and such where spare motors etc., are stored. It could have been subject to electrical tracking or arcing, especially if any welding has been done near it without taking precautions. As there is only one roller involved you can be pretty sure that it has been stationary when whatever caused it occurred, ruling out lack of lubrication.

[Phil B]

That appears to be a from of "brinelling". There are several things that may cause it. It could just be a poor quality bearing where the hardening process is faulty. Bearings stored before use in a situation where there is a small but intense vibration and the bearing has been stored "upright" or on edge. This can also happen after the bearing has been installed where the equipment itself is subject to vibration. A big problem on ships and such where spare motors etc., are stored. It could have been subject to electrical tracking or arcing, especially if any welding has been done near it without taking precautions. As there is only one roller involved you can be pretty sure that it has been stationary when whatever caused it occurred, ruling out lack of lubrication.

Very interesting and logical about the welding. Thanks!

[djam1]

Were the bearings genuine RHP ?

[vnx205]

Yes. RHP.

[djam1]

When the bearings were done at 160k Was the wear pattern similar
Some boxes seem to do it and others don’t I wonder if it is an alignment issue with the housings
But yours looks like a bad bearing to me

[vnx205]

No, it was quite different.

Last time it was the other bearing and the wear pattern was exactly what I would have expected.

The inner race was worn or pitted all the way around and all the rollers had similar wear all the way around.