[EJOE12345]

I did not expect to run into such a weird issue when finding this part.i have a 2006 BMW 325i with the 6MT. Essentially, I ordered the drain/fill plug for my 6MT transmission from FCP. I got these, https://www.fcpeuro.com/products/bmw...ug-23127602815 . It doesn’t come with a seal, which I thought was weird. But the 2006 BMW 325xi has a seal and the part # is linked to a different drain/fill plug https://www.fcpeuro.com/products/bmw...ug-23117531356 . So technically, the first link without the seal should be the one but I find it really hard to believe that the 325i version of the 2006 6MT Beamer doesn’t have a seal but the XI does. I also don’t think the XI plug would fit since it’s a slightly different sized bolt Any thoughts?

[StradaRedlands]

Edited because I can't read... transmission!

Neither of those links work, I think because there is a . at the end of the url?

So looks like the first one should work, but like you said, would need some sort of washer on it. The second one has a built in o-ring, which may be fine? While I have a MT, the previous owner did the trans fluid on mine, so I haven't had to do it yet.

[EJOE12345]

Originally Posted by StradaRedlands

Edited because I can't read... transmission!

Neither of those links work, I think because there is a . at the end of the url?

So looks like the first one should work, but like you said, would need some sort of washer on it. The second one has a built in o-ring, which may be fine? While I have a MT, the previous owner did the trans fluid on mine, so I haven't had to do it yet.

They should work now. And I’m not sure if the one with the built in seal would work. The size of the one that matches my vehicle is size M18X1,5X12mm. The one with the built in is M18x1.5 . Are those two sizes interchangeable?

[Efthreeoh]

Originally Posted by EJOE12345

They should work now. And I’m not sure if the one with the built in seal would work. The size of the one that matches my vehicle is size M18X1,5X12mm. The one with the built in is M18x1.5 . Are those two sizes interchangeable?

The 325i manual transmission and the 325ix manual transmissions are different from each other, so they use different plugs. The 325i plug is M18x1, which means the thread pitch is 1 thread per 1 millimeter of shaft length and is considered a "fine" thread. The 325ix plug is M18x1.5, which is 1 thread every 1.5 millimeter, which is considered a "course" thread. Course thread requires a rubber seal embedded into the plug because the oil can pass through the thread easier than the fine thread design.

Because the thread pitch is different for each plug they are not interchangeable.

Having changed the oil in my transmission 3 times since new, the drain plug has never leaked (when properly torqued). I've used the original plug that came from the factory (i.e. I've never bought a new plug). There is an internet myth going around that you should use new drain and fill plugs each time you drain and fill the transmission. There is no need to use new plugs. Keep in mind the fill plug sits above the oil level line so the oil really can't leak out anyway.

[EJOE12345]

Originally Posted by Efthreeoh

The 325i manual transmission and the 325ix manual transmissions are different from each other, so they use different plugs. The 325i plug is M18x1, which means the thread pitch is 1 thread per 1 millimeter of shaft length and is considered a "fine" thread. The 325ix plug is M18x1.5, which is 1 thread every 1.5 millimeter, which is considered a "course" thread. Course thread requires a rubber seal embedded into the plug because the oil can pass through the thread easier than the fine thread design.

Because the thread pitch is different for each plug they are not interchangeable.

Having changed the oil in my transmission 3 times since new, the drain plug has never leaked (when properly torqued). I've used the original plug that came from the factory (i.e. I've never bought a new plug). There is an internet myth going around that you should use new drain and fill plugs each time you drain and fill the transmission. There is no need to use new plugs. Keep in mind the fill plug sits above the oil level line so the oil really can't leak out anyway.

This makes total sense. Thanks for the detailed explanation. So no seal is needed and I am all set, just a proper torque. Is the torque spec different for each or are they the same? Thank you!

[Efthreeoh]

Originally Posted by EJOE12345

This makes total sense. Thanks for the detailed explanation. So no seal is needed and I am all set, just a proper torque. Is the torque spec different for each or are they the same? Thank you!

Per BMW's general torque specs I grabbed off the TIS back in the day, the torque is a low 37 pound-foot. Use a beam type torque wrench. All it needs to be is tight, don't over-crank on it.

Make sure you can access the fill bolt first and loosen it BEFORE you drain the transmission. You do not want to have an empty transmission and not be able to open the drain bolt to refill it. Access to the drain bolt location is a bit tight because it is up close to the passenger-side of the transmission tunnel.

[EJOE12345]

Originally Posted by Efthreeoh

Per BMW's general torque specs I grabbed off the TIS back in the day, the torque is a low 37 pound-foot. Use a beam type torque wrench. All it needs to be is tight, don't over-crank on it.

Make sure you can access the fill bolt first and loosen it BEFORE you drain the transmission. You do not want to have an empty transmission and not be able to open the drain bolt to refill it. Access to the drain bolt location is a bit tight because it is up close to the passenger-side of the transmission tunnel.

Gotcha, thank you for the help!

[EJOE12345]

Originally Posted by Efthreeoh

The 325i manual transmission and the 325ix manual transmissions are different from each other, so they use different plugs. The 325i plug is M18x1, which means the thread pitch is 1 thread per 1 millimeter of shaft length and is considered a "fine" thread. The 325ix plug is M18x1.5, which is 1 thread every 1.5 millimeter, which is considered a "course" thread. Course thread requires a rubber seal embedded into the plug because the oil can pass through the thread easier than the fine thread design.

Because the thread pitch is different for each plug they are not interchangeable.

Having changed the oil in my transmission 3 times since new, the drain plug has never leaked (when properly torqued). I've used the original plug that came from the factory (i.e. I've never bought a new plug). There is an internet myth going around that you should use new drain and fill plugs each time you drain and fill the transmission. There is no need to use new plugs. Keep in mind the fill plug sits above the oil level line so the oil really can't leak out anyway.

Okay so, I went to do the job today and the bolts that came out were actually the longer ones with the green gasket. The shorter ones without gaskets fit but I didn’t want to mess things up. So I just put the fill plug back in and will order the bolts w/ green gasket