Crank scraper install -- rear cover seal trimming?

[Som]

I'm installing the IJ crank scraper and I'm not really clear on one of the instructions regarding the rear cover.

I've got a 12/86 build 325i. Apparently not all the E30/M20s have this, but the rear part of the oil pan had a little cover that bolts into the bottom part of the transmission. There's a little rubber seal where this cover presses against the oil pan.

The instructions say that if you have this, you "trim the seal 2.5mm" to prevent applying too much pressure to the cover or the block when you bolt it back down.

I'm not clear on where/how to trim this piece. Trimming the length seems pointless... and the whole thing appear to only be a few mm deep, so 2.5mm seems like a lot to scrape off with a razor (plus, I'm not sure how you even do this evenly).

Part is #29 here: http://www.realoem.com/bmw/showparts...19&hg=11&fg=10

I feel like I'm missing something easy here...

Som

[TobyB]

uhhh, that thing just keeps shit out of the bellhousing- what could it have to do with
the crank scraper, which should be INSIDE the oil pan?

Now, I ran into a clearance issue with the IE scraper that stuck out of the
gap between the oil pan and block- THAT needed to be trimmed down to
get things to clear. But I find that to be common with IE E30 parts...

So I wonder if the IJ scraper also sticks out of the 'gasket gap' a bit- that might
make the aluminum piece not sit right?

t

[Som]

The cover bolts into the block. If you imagine the crank scraper + gasket adding a ton of thickness -- like, say, 1 cm -- between the block and the pan, then it becomes easier to see the concern. When you bolt the cover into the block, the cover will press harder against the oil pan -- potentially hard enough to damage it.

That said, I posed the question in the SpecE30 forum and it sounded like many people just reinstall without modifying the seal at all. I did the same... doesn't seem to have caused any issue. That said, I ended up going with the block-RTV-scraper-cork gasket-pan assembly.

Som

[TobyB]

Ah, you're right, the pan DOES grow a bit, doesn't it?

I never noticed- bolted it all up, and it seemed to be fine.
I used 2 gaskets and a scraper, so I added about as much as you can...


t