Oil pump drive shaft o-rings

[TB123]

I removed my oil pan and pump and found one of the small orange/red o ring washers from the pump shaft at the bottom of the pan broken in half. I'm not sure if I broke it or if it's been sitting in the pan for a while. What is the purpose of these two plastic o rings on the pump's shaft?

[digger]

do you mean the white plastic ones in the skinny shaft? i think they just stop the shaft moving axially

[TB123]

I'm talking about the ones on the skinny shaft that goes down into the oil pan. Not on the intermediate shaft itself, but on what I thought was called the oil pump drive shaft. On my engine they are orange.

When I slide the shaft into the oil pump, there is no contact between the o rings and the pump, so I don't see how it can stop any in and out axial movement.

I'm not sure where I can find a replacement. If anyone knows of a part number or can send me a link, that would be great!

[turbo55]

I just did the same job last weekend, one of mine also broke. It didn't seem like they were necessary on both ends (I tried putting it in both the oil pump and the drive), so when putting it back together I put the side with the plastic piece where it could move and left the other without it. Can't remember which side I thought needed it though...

[TB123]

I just did the same job last weekend, one of mine also broke. It didn't seem like they were necessary on both ends (I tried putting it in both the oil pump and the drive), so when putting it back together I put the side with the plastic piece where it could move and left the other without it. Can't remember which side I thought needed it though...

Yeah they really don't seem necessary to me, but I am a little worried to leave one of them out if for some reason that I am not seeing, it is required.

[AndrewBird]

I'm not familiar with M20 oil pumps, but they seem to be there to correctly space the driveshaft and drive gear. The drive gear won't engage it's mating gear as much with one of the spacers missing.

They appear to be fiber washers. I'm sure you could find some either fiber or plastic washers at your local hardware store. Just get one either close to the same thickness, or stack a few thinner ones to get it close.

[digger]

They are hard plastic i have a new setup ready to be installed and they are a tight fit. They would go brown when used as the oil will change the color. Last time I installed them I slid them such that the hex shaft engaged both the hex drive for the pump and little gear “properly” as the shaft would slide up and down a bit if I didn’t limit the axial travel with the washers i centralized it IIRC

[TB123]

They are hard plastic i have a new setup ready to be installed and they are a tight fit. They would go brown when used as the oil will change the color. Last time I installed them I slid them such that the hex shaft engaged both the hex drive for the pump and little gear “properly” as the shaft would slide up and down a bit if I didn’t limit the axial travel with the washers i centralized it IIRC

That makes sense. The one on my shaft may have been pushed on too far by the previous owner. My shaft bottoms out in the pump before the washer makes contact.

Where did you you get your new ones? Did they come with a new pump?
I'm going to try to find some nylon washers locally, or I may try to machine one. My only concern is making sure that the material I find is resistant to heat and engine oil.

[digger]

might have come with a new shaft but dont remember 100%

IT11

http://www.realoem.com/bmw/showparts.do?model=1112&mospid=47263&btnr=11_0446&hg=11&fg=30

[TB123]

IT11

http://www.realoem.com/bmw/showparts...46&hg=11&fg=30

thanks!