/7 rear drive wear

[dwerbil]

Doing a bit of afternoon maintenance on the /7 today, and the metal flecks in the rear drive oil
start a'showin' up. 125k miles.
To the right of the penny, in the oil. I should have sopped more oil out of there for the photo....




The brass and silver colored shavings were a bit noticeable when
doing the finger-grit test. There were enough flakes to cover about half of Lincoln's penny-sized head.
This is the first time this 'color' flaking has shown up on a rear drive oil change. Usually the drain
plug has a little bit of a grey-talc goo it, with no grit feeling.
Still more miles in the thing?

[grant81rs]

Gidday Fellas,

Incredible, its the first old beemer I have seen that actually generates disposable cash for the owner prior to a sale, trying riding it a little harder as the next coin may come out gold..

[SteveD]

Where would the brass colourings come from?

[Airbear]

Where would the brass colourings come from?

I was wondering that myself. I don't recall anything brassy/bronzey in there and mine didn't have coins in it.

Duane's yer man for this one, I reckon.

[dwerbil]

I don't know the innards of those rear drives, much less any innards on these bikes. A number of the flecks did have
a brass looking tint to them along with the rest being silver colored.

[robert]

The spacer/shim on the right side of the ring gear carrier that sets the backlash is bronze on most of them. I have seen them fail.

[Airbear]

The spacer/shim on the right side of the ring gear carrier that sets the backlash is bronze on most of them. I have seen them fail.

Ah, of course - it's all flooding back. Thanks Robert.

[robert]

The spacer/shim on the right side of the ring gear carrier that sets the backlash is bronze on most of them. I have seen them fail.

Ah, of course - it's all flooding back. Thanks Robert.

Possible failure could be from too much preload of the carrier bearings.

[Duane Ausherman]

I want to see the wear pattern on the gears.

[SteveD]

This is what you don't want to see.


Play developed at the pinion gear bearing. It was asymptomatic. I found it at routine oil change.