Chaincase oil seal disc

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Apr 15, 2004
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I have a question about the inner chaincase. The felt seal sits in a sliding sheet metal carrier, which allows it to center itself on the mainshaft when you adjust the primary chain tension.

On my 850, that sliding carrier does not slide. It's badly rusted and is frozen solid to the chaincase. Penetrating oil so far has not been able to free it.

I see replacements are readily available, p/n 06-0769 "chaincase oil seal disc". They're fairly inexpensive too.

But how do you remove the old ones and install the new ones? It appears to be two pieces that are pressed together. Do you just pry them apart with a screwdriver or something? It's not at all obvious (to me anyway), but it must be possible somehow.

I just did that this weekend! This one was already bent up so I used a screwdriver to bend it up until it pushed through. If I were doing it again with a unit that wasn't already bent, I would drill out the spot welds (they are close to the center of the discs) to separate them.

When installing the new one, I was fortunate that a friend has a spot welder. It is a little tricky to line up the two plates over the inner cover. We used a couple long reach welding clamps to line it up, but they would not reach to pull the two pieces together where the spot welds should be. We used a large diameter bolt and washers to pull the centers together, then spot welded the discs together in three spots. If you don't have a spot welder, try to find a sheetmetal shop with a biker friendly owner.

The unit doesn't move easily, but it doesn't need to as it only moves when adjusting the primary chain. The closer the fit, the less likely to weep oil mist.

Fitting the new felt is best done with a couple of small bladed screwdrivers.
inner chain case seal plate

The first time I installed a set of those plates I thought it would be OK to epoxy them together....wrong. The second attempt I just drilled 4 1/8 inch holes evenly spaced around the shaft hole on one of the plates then used my Mig welder to spot weld them together. Now that I have converted to belt primary I have just removed them for ventilation.
Thanks guys, good info there. We do have a guy in the club who could probably do the spot welding so I may be in luck :)

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