sierra9260 4 Report post Posted February 17, 2014 (edited) I have a 1988 Bmw e30 320i M20B20. It has a Getrag 240 5 speed gear box. I thought it best before I drive it too much after it has just had a new manual conversion, that I change the gear box oil. I have had a search through some forums and there seems to be a lot of different types you can get. I also learnt sometimes there are tags on the bell housing that indicate which oil should be used. I thought I would ask some local people as I would get a better idea and have some more up to date knowledge on what oil to buy for the 240. Also how is it drained out then filled? There is a small port on top of the gear box with a plastic cap in it... is it filled in through here? There is what appears to be a plug which has an inverted hex indentation of about 17mm, on on bottom of the box. Is this the drain plug? I know how to fill the crank case oil but I was wondering what a good oil would be for an M20. Thanks guys. Edited February 17, 2014 by sierra9260 Quote Share this post Link to post Share on other sites
antil33t 90 Report post Posted February 17, 2014 Gearbox is filled from the side through a plug, it will be like that hex indentation you see except further up. - undo this one first. There's another one below it that is the drain. Quote Share this post Link to post Share on other sites
sierra9260 4 Report post Posted February 17, 2014 Great thanks for that. I'll take a look. How much oil does the gear box take so I know how much to put in with a pumper Quote Share this post Link to post Share on other sites
Eagle 1662 Report post Posted February 17, 2014 Should be specs on the net. Usually around ~1.2L Quote Share this post Link to post Share on other sites
E30 325i Rag-Top 2957 Report post Posted February 18, 2014 Use a good quality Gear Oil, from a named brand, EP80 I think is the grade and you will be sweet. The principle is you keep pumping it into the filler hole until it comes back out at you - that tells you it's filled to the right level!! Quote Share this post Link to post Share on other sites
Allanw 1071 Report post Posted February 18, 2014 ALWAYS remove the filler plug BEFORE the drain plug! If you drain it, then can't fill it' you're a bit screwed! Quote Share this post Link to post Share on other sites
Kepes 231 Report post Posted February 18, 2014 I used Redline MTL for my trans. It was $40 a litre and i got two bottles/litres. still 3/4 left in the second bottle. Yes it's very expensive but it greatly improved my shifting making it feel less notchy/sticky. Anyway, whatever you go with make sure you use a GL-4 oil. And as mentioned, undo the filler plug before undoing the drain plug. I had trouble with the filler plug so I took it to the mechanic. Oh also, both plugs are 17mm hex/allen. that was for my Getrag 260. Not sure if the 240 is the same Quote Share this post Link to post Share on other sites
Eagle 1662 Report post Posted February 18, 2014 $40 shiiit, i paid $26 at BNT like 2 weeks ago. Quote Share this post Link to post Share on other sites
Kepes 231 Report post Posted February 18, 2014 $40 shiiit, i paid $26 at BNT like 2 weeks ago. Weird, bought it at BNT in Wellington. Would have been just before christmas i think Quote Share this post Link to post Share on other sites
sierra9260 4 Report post Posted February 18, 2014 Weird, bought it at BNT in Wellington. Would have been just before christmas i think Wow awesome response to this guys. Always thankful for the guidance. I will give BNT a call tomorrow and try and sort some redline MTL for a decent price and fill this sucker, see how it does. Quote Share this post Link to post Share on other sites