How much different is the pre 1981 model final drives that they didn't require this "protection plate"? The fiche says it began use in 9/1980. Why don't the earlier FDs spew oil??
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'78 R100/7 & '69 R69S & '52 R25/2
mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!
I would have to say its the shape of the casting and the vent itself is built differently. The problem with making a puke line for it is you can run the gear oil right out of the F/D on a long ride and damage it. I would have to guess that the F/D's out there without the baffle were resealed at one point and the wrench that did the work got it back together then realized the baffle plate was still on the bench. Didn't want to waste a gasket so the baffle got tossed. There's a ton of those late model F/D's out there so I'm sure someone will have a spare one you pick up. Takes about three hours and $25 in parts to pull one apart and reseal it if you don't have to re-shim or put new bearings in. Mark Hugget may have those baffles, he seems to have a lot of N/L/A stuff.
Apparently my final drive doubles as a hydraulic pump. Took it out this morning. Went about 10 miles no faster than 45 mph. No oil in the vent tube i installed. Hit the highway and did about 4 miles at 70-75 mph and this picture was the result. Got back home and nearly all the oil had drained back into the FD. Lost no oil and the rear tire stayed dry. Thanks for all of the help.
Yes, but probably not until the riding season is over and the bike is in my basement. This fix just keeps me riding for now.
One thing that probably isn't helping your situation any is that it appeared that the cap of your vent was shoved all the way down to the top of the threaded nut insert in the final drive. It should be up above the top surface of the nut by a few millimeters so that it is open to normal atmospheric pressure through the tiny holes at the top under the mushroom cap. Otherwise, it may be that there is no air flow/venting going on, and as the final drive heats up under high speed riding, things expand (including the air inside the drive) and it forces things to squirt out under pressure. I have seen this happen on final drives where the oil is forced out of various seals in the final drive, coating the rear wheel in FD gear oil. Simply making sure that the little vent holes in the top of the cap were not plugged, and ensuring that the vent was not shoved all the way into the sleeve of the final drive (it should look like a "mushroom" with a couple mm of "stem" showing ) and it fixed the problem.
BMWs in my garage: 1982 R65LS, 1978 R100/7
The vent was operating properly. Must just be the angle of the picture that makes it look like you described.