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Today, a bit sad and depressed about my airhead

Posted: Thu Jul 04, 2013 11:00 pm
by Lifebeat
Hello again... I'm in for a tap on the back...

Let me just give you a very quick recap of where I'm at and what I'm going to do...

1976, R75/6
Purchased 3 weeks ago, in a "running" state... ( I just wanted to get through summer before doing a big job on her this winter...)

So, after a lot of reading and trying to understand stuff, here is what I will be doing (parts ordered or on hand), in order to get her basically up to "safe" riding specs, and this all comes from an understanding that a basic tune up is called for:
-Change points
-Change condenser
-change coils (Bosch BLues on order)
-change spark plug cables
-change spark plugs
-do an extensive overhaul on the Bings (order a kit from Bing USA, hope this wasn't a mistake?)
-regular oils and filters and air stuff is not even an issue here, they will be done
-change throttle cables (because they are frayed on one side... Best source for these?? BMW Dealer?)
-Adjust timing
-Sync carbs
-Rebuild caliper (because my braking is the shits)
-Rebuild Master cylinder (because my braking is the shits), change front brake cable

THEN!!! I might be happy.

BUT!! today, knowing all of this, and feeling confident, I thougth to myself : meh, I'll just take her to work today (30 miles) and see how she does...

Result : me being sad and depressed, that I got involved in a money pit... But all day long trying to talk myself into remembering that this is what I wanted : an original bike, that has history, and that reflects what I want to ride.

I will post a link to some pictures below... When I originally got the bike, first reflex was to check oil levels and the like, to make sure I could at least start the thing. Ends up that the drive shaft filler plug/bolt had been stripped before and had a Helicoil put in. While I was attempting to tighten is down to a reasonable torque, the Helicoil stripped the aluminium housing and started pulling out... I thought : OK, this isn't a biggie... Nothing is going on here so I'll just leave it until this winter. Then yesterday, while I was contemplating taking her to work, I decided to put some plumbers paste on the remaining threads, just to make a better seal...(in hindsight, don't know If I should have...)

So today, I drive all the way down to work, and when I get there, and put her on the center stand, I notice all this oil dripping down from the rear fender, the final drive casing, pretty ,much everywhere on the right side. It's like there was pressure generated in the drive shaft housing, and it pushed the oil out. I was able to get to an old small town garage and get a refill on gear oil, just to have peace of mind to get it back... On the way back, it emptied itself again...

Question : is this bolt/plug supposed to be vented? Is the vent on the top of the final drive case connected in any way to the end of the drive shaft portion? (you know, the vent that is at the top most portion of the final drive case)

Other question : Obviously, I either need : an over sized Helicoil OR to rebuild the original hole with a TIG welder and tap in again right? Can I do any or both of these without taking apart the final drive case? I was just looking into the final drive procedure in Clymer, and oh boy... not now... Maybe this winter...

Please give me some guidance here... I was actually, for about 30 minutes, considering getting a 2005 Honda something that just runs... But then I remembered I actually "wanted" this.

Lastly, considering I've never had a big bike before (I'm a classic Vespa guy), is it normal that I find the handling and steering of the airhead VERY heavy? New tires, good pressure, steering bearing without play and not stiff... Pretty sure the front brake sticking doesn't help the feeling when I get to a stop light... But still, I feel "dominated" a bit by the bike...

Thanks again for your attentive ears

Luc
http://www.flickr.com/photos/97761109@N03/9125383069/
http://www.flickr.com/photos/97761109@N03/9210034014/
http://www.flickr.com/photos/97761109@N03/9210035818/
http://www.flickr.com/photos/97761109@N03/9207257029/

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 1:11 am
by esman100
If you want to ride it now without doing a proper fix you can put a small tapered pipe plug in it to seal it.

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 1:43 am
by Deleted User 287
To the other guys - is his shaft-to-final drive seal allowing the shaft oil to migrate to the final drive?

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 2:08 am
by Deleted User 62
justoneoftheguys wrote:To the other guys - is his shaft-to-final drive seal allowing the shaft oil to migrate to the final drive?
Sounds like it. If the oil overflows when you remove the fill plug on the final drive, it's making it past the pinion shaft seal. Any oil that leaks out and gets on the tire will be flung everywhere. I just fixed this exact problem on my '72. The Cycle Works tools made it a breeze! As a temporary fix you could just grease the drive shaft splines, GS style. If you do need to re-tap that hole, there's no time like when all the stuff you have to remove to change the pinion seal is out of the way...

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 7:27 am
by Lifebeat
OK, I see where you are pointing at, it's just that when I got the bike, I rode her about 50 miles on that first day, and no oil leaks. This started after, when I checked my levels. Shaft drive was OK, and final drive was OK. When I put the plug back in on the drive shaft filler hole, that's where I pulled the Helicoil, and from what I can see (stopping at regular intervals on the side of the road), it's coming out of this filler screw plug. The oil from the final drive couldn't migrate back UP in the drive shaft part right?
Thanks

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 8:07 am
by Ken in Oklahoma
Lifebeat wrote:. . . The oil from the final drive couldn't migrate back UP in the drive shaft part right?
Unlikely, but oil could be migrating from the transmission to driveshaft seal.


Ken

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 9:32 am
by Lifebeat
So then, considering the amount that I have lost yesterday, the gearbox level should be on the low side now right? Will check tonight.

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 9:44 am
by Duane Ausherman
Lifebeat wrote:OK, I see where you are pointing at, it's just that when I got the bike, I rode her about 50 miles on that first day, and no oil leaks. This started after, when I checked my levels. Shaft drive was OK, and final drive was OK. When I put the plug back in on the drive shaft filler hole, that's where I pulled the Helicoil, and from what I can see (stopping at regular intervals on the side of the road), it's coming out of this filler screw plug. The oil from the final drive couldn't migrate back UP in the drive shaft part right?
Thanks
Lifebeat, one can't "check" the driveshaft (swing arm) level except by draining and refilling. After the levels are correct and you see no leaking, the way to check the swing arm is to look at the final drive level. If it is high, then the swing arm level is low. Being a bit low isn't dangerous. In fact I prefer it to be low.

The Helicoil was needed because someone was holding a wrench that shouldn't have been allowed to touch things with moving parts. :D They used too much muscle. This is an indication that you will probably find that this happened more than once. Be prepared to go over the bike carefully.

When oil migrates from the swing arm to the final drive, it could go by 3 paths, not just the seal. Info on my website.

I don't recall seeing oil migrate forwards from the final drive.

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 12:24 pm
by Lifebeat
Ahhh OK!
But I thought I was measuring something with the old BMW manual I picked up on the web. It said something like 2mm above an indicator put in that hole... Which I found strange because there are various heights at which you can insert a stick in there.

So do you think I can redrill for a Helicoil without completely taking appart the final drive? If I DO have to take it appart, wouldn't it be a nicer job to just fill the hole again with TIG welding and cutting new threads?

Luc

Re: Today, a bit sad and depressed about my airhead

Posted: Fri Jul 05, 2013 12:31 pm
by Jean
I wonder that your SPs aren't helicoiled too.
Driveshaft - It's not the end of the world. Examine the remaining threads and try replacing the helicoil if possible. Then try the taper thread plug.
Anybody on the forum live close to you that can help?