Oil Level Sight Glass replacement?

That looks _exactly_ like what I mentioned. It really appears to have been whacked hard enough to punch the aluminum backing out. In other words, the sight glass was driven in too deep.

Maybe carry a rubber expandable freeze plug and some oil- just in case.
OM

Tool for installation?

Is a BMW tool available for purchase that can be used for this task? How about a BMW tool for removal?

It's a seal, nothing more complicated than that except no shaft running through it.

Looking at the damaged shoulder, I doubt that was done at installation of a previous sight glass but rather some exuberance with a screw driver or some other pry bar when removed before

I think the remnants of the shoulder could be found in the media of lost and long forgotten oil filters.

When installing a seal, always prudent to use a driver that mates the OD face of the seal and best if the driver has a shoulder to make sure the seal is driven flush.

Good luck with that. I defy anybody to drive a seal in square while on your hands and knees or even in a perfect position with a hammer.

There are a number of "goops" on the market specific to use on the OD of the seal and some work pretty well and some too well. I like to use Permatex "Right Stuff" if I have no issues with ID burrs/scoring and if I do, Caterpillar makes this green stuff that works really good.

So good, you will never, ever, remove the seal in the lifetime of a sea turtle.

dieselyoda said:

Caterpillar makes this green stuff that works really good.

So good, you will never, ever, remove the seal in the lifetime of a sea turtle.

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Which solves the leak problem but good luck when the lens clouds over rendering it useless for checking oil. Voni's R1100RS had a "loose" fit. I could push the lens assembly in with my thumbs. I used Loctite Black Max, a rubberized super blue on the back side of the rubber surround. That sealed and had an adhesive effect but still allowed removal. On all of our other oilhead or K bikes I install clean and dry per BMW procedures.

PGlaves said:

On all of our other oilhead or K bikes I install clean and dry per BMW procedures.

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As per, "Caterpillar", "Cummins", "Detroit", "Allison", "Meritor", "Eaton", "Rockwell", "Komatsu", "Volvo", et el, the manufacturer might give you a way to do a thing or two but if you trust them as gospel, then your McDonald's has the healthiest breakfast fries.

Common sense and failure leads to experience and to the best of my knowledge, there isn't a service manual written that has either.

And with breakfast fries goes a breakfast beer.

rad said:

The back roads blow out is not as common. I have noticed that most people have theirs go just like you did, upon start up at the beginning of the day.

Mine did the weep thing, so I replaced it.

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Yup, things like to break at startup. And it makes sense because the oil is as thick as it can be and the initial startup oil pressure is usually very high. Confirm this with an Oil Pressure Gauge.

But is the sight glass under any pressure besides typical crankcase pressures? I'm not sure how that would vary significantly between hot and cold.

Signed,

Willing To Be Educated

If the crankcase vent isn’t working there can be quite a bit of pressure. On my 1979 Honda CB750, there was a rather involved H shaped valve cover gasket that would not stay sealed resulting in oil on my pant leg and shoe.
I stumbled on to the cure for the gasket blow out which was to pull the plug on the lower crankcase hose which allowed the condensation to drain, the crankcase to breathe and the valve cover to stay sealed.
Anyone remember a 225 slant 6 with a bad PCV valve?
OM

Omega Man said:

If the crankcase vent isn’t working there can be quite a bit of pressure. On my 1979 Honda CB750, there was a rather involved H shaped valve cover gasket that would not stay sealed resulting in oil on my pant leg and shoe.
I stumbled on to the cure for the gasket blow out which was to pull the plug on the lower crankcase hose which allowed the condensation to drain, the crankcase to breathe and the valve cover to stay sealed.
Anyone remember a 225 slant 6 with a bad PCV valve?
OM

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Oilhead crankcase venting keeps the base pressure at minimum.

GSAddict said:

Oilhead crankcase venting keeps the base pressure at minimum.

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Yes but: The change in pressure from those two big pistons moving inward together and outward together is much greater than on the K series bikes with 3 or 4 or 6 pistons going every which way as the crank rotates.

I can't explain the physics, but all of the 5 or 6 cases of blown sight glasses I am aware of happened at cold start up. The first was when Voni's R1100RS was one month old in June 1993. It happened near Salt Lake City. She was towed in to the dealership when, as it happened, the VP in charge of motorcycles at BMWNA was visiting the dealership. (So was Harrison Ford but that's a different story.) They had a new sight glass overnighted from Germany.

PGlaves said:

Yes but: The change in pressure from those two big pistons moving inward together and outward together is much greater than on the K series bikes with 3 or 4 or 6 pistons going every which way as the crank rotates.

I can't explain the physics, but all of the 5 or 6 cases of blown sight glasses I am aware of happened at cold start up. The first was when Voni's R1100RS was one month old in June 1993. It happened near Salt Lake City. She was towed in to the dealership when, as it happened, the VP in charge of motorcycles at BMWNA was visiting the dealership. (So was Harrison Ford but that's a different story.) They had a new sight glass overnighted from Germany.

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Agreed but my point was the oilhead is different than an auto engine with a PCV valve.

GSAddict said:

Agreed but my point was the oilhead is different than an auto engine with a PCV valve.

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And my main point was on the Honda CB750K. The automotive reference won’t mean anything unless someone has seen it. Two of the generators (325KW) I mind just puked oil due to poor crankcase vent design/venting. When an engine “pumps”, pressure changes and needs compensation.
OM

Seems mine on my 97 r bike needs replaced. Can't see the oil level anymore. Has anyone tried using air pressure inside the crankcase while trying to remove the sight glass? Just enough so if it brakes, it doesn't go into the engine? Of course, safety glasses would need to be worn...just a thought.

slime said:

Seems mine on my 97 r bike needs replaced. Can't see the oil level anymore. Has anyone tried using air pressure inside the crankcase while trying to remove the sight glass? Just enough so if it brakes, it doesn't go into the engine? Of course, safety glasses would need to be worn...just a thought.

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It is not that complicated. There is a metal piece with holes inside the assembly behind the lens. Just MELT a hole in the lens near the center with a soldering iron and use a screwdriver or similar tool to pry the assembly out. Melting the hole thickens the edges around the hole and also tends to eliminate cracking of the lens as you pry the assembly out.

slime said:

Seems mine on my 97 r bike needs replaced. Can't see the oil level anymore. Has anyone tried using air pressure inside the crankcase while trying to remove the sight glass? Just enough so if it brakes, it doesn't go into the engine? Of course, safety glasses would need to be worn...just a thought.

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In a word NO.

The pressure needed to pop the glass out will also drive the oil seals out.
Simple job, just pry it out.

This topic arises from time to time. Following is a link from the Snowbum website -

https://bmwmotorcycletech.info/sightglass.htm

Here is a link to a video from Moto Phoenix showing this procedure -

<iframe width="560" height="315" src="https://www.youtube.com/embed/VVcwkB9qFcI" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Shel is a gal that makes videos of her working on bikes. This video is not as clear on the procedure (limited space to place camera), but she uses a soldering iron (must have been with sight glass with plastic rather than glass).

<iframe width="560" height="315" src="https://www.youtube.com/embed/em2K0v6a6Zc" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


This fellow shows part of his process to remove a sight glass that has a circlip. This sight glass did not come out easily!

<iframe width="560" height="315" src="https://www.youtube.com/embed/B4Mj2R8KGgw" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


Unrelated to engine oil sight glass removal, but here is an interesting video from Boxer 2 Valve folks showing a sight glass for transmission level checking -

<iframe width="560" height="315" src="https://www.youtube.com/embed/--sxUZQz9h0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>





I also found some pictures of interesting ways folks secured their sight glass devices before the circlip was added.

Went to Max's fiche to see about having a spare.
There is a PDF next to the part that shows how to remove and install it.
Many different tools to clean out, some not mentioned here.
Maybe worth checking out.

Would judicious use of heat around the casing help loosen it?
Does anyone make a dipstick option?

jnrugg said:

Went to Max's fiche to see about having a spare.
There is a PDF next to the part that shows how to remove and install it.
Many different tools to clean out, some not mentioned here.
Maybe worth checking out.

Would judicious use of heat around the casing help loosen it?
Does anyone make a dipstick option?

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Yes, I saw those. I ordered one from Beemer Boneyard. Max had them cheaper last week, for some reason. I was going to order the factory one from them. Went back yesterday, and it was the standard price so I ordered the aftermarket unit.