[Skibum]

Folks,

I am going to do the initial "break-in" change of the manual transmission oil in my 2012 550i. The car has very low mileage (3300), so it is time to perform this maintenance. BMW recommends changing the manual trans oil in the M5 at about 1200 to 1500 miles.

The transmission is the very stout ZF GS6-53BZ 6-speed manual. It's a good 30 lbs heavier than the GS6-45BZ manual that was used in the 535i.

My question is simple: Which of the two plugs on either side of the transmission case is the correct fill plug to use? The "logical" one is this one on the lower left (drivers) side: https://www.flickr.com/photos/25092028@N05/17145005370/ Highlighted by the red hexagon
This plug is located about 2" above the lowest point of the case, and therefore adding enough oil to fill to this point would likely result in the proper quantity.

However, there is what appears to be about a 17mm hex-head bolt (plug) on the upper right side of the case. Traditionally, the fill plugs on most ZF manuals (and Getrag manuals for that matter) have been located on the right side of the case. I wonder, could THIS be the proper fill point if ZF engineers employ some kind of internal fill tube that runs from this opening all the way to the bottom of the transmission case, so that once you've added sufficient (approx 2 litres) MT oil, the oil will then move up the internal fill tube through some combination of vacuum and capillary action and begin to spill out of this hole way up high on the case? Here's a photo of that plug: https://www.flickr.com/photos/25092028@N05/17332595425/ Highlighted by the red square

I can't find anything online regarding basic servicing of the GS6-53BZ 6-speed used in the F10; at least not without signing up on www.bmwtis.com and paying a ridiculous amount of money. And in my case, just to answer one lousy question. Yes, I can ask a service tech at one of my two local BMW dealers, but I thought I'd ask here first, as there is a wealth of knowledge and experience on this forum. So, does anyone know which plug is the fill plug?

I greatly appreciate hearing from anyone who has solid info on this!

Best - Rodger (Skibum)

[BDJL]

The fill on my F10 550i with the same GS6-53BZ transmission is on the left side above and slightly forward of the drain plug location. It takes the same 8mm hex and looks like the drain. You will want to be cautious as with the pumping system the level can be above the fill hole depending on the position of the car on the stands.

I measure mine at removal and refill with the amount that came out. In my case it was 2.4 liters. The manual for the dealer has them using the BMW diagnostic tool to run the pump for 30 seconds or so but not an option for home users.

On your picture the fill plug is the one you have with a red hexagon around it.

[windowmaker]

Confirming BDJL. I've done the MT fluid change and that is the fill plug. I've also read it's recommended to change the filter at the regular interval (may not apply for your low mileage case), which runs ~$50.

Btw I like the gopher shot. Nice family photos :P

Edit: Just noticed this is a revived thread from 2015, and based on your updated signature you don't have the 550 anymore *facepalm* well maybe the next owner will change the filter. :P

[whinojosa]

I didn't know MT's have filters! I believe those are only in AT's.

I changed my fluid to Redline MTL and my existing fluid was toast. Prob gonna change again in a few months for good measure.