Baby BMW Forum banner

How To Change Your Gearbox Oil

128K views 181 replies 62 participants last post by  p0otzz 
#1 ·
This is a guide for changing your gearbox oil, this relates directly to a 120d, but I'm sure it would be a similar procedure for any BMW. I did mine on a ramp, which is preferable to stands.

Before you start, you'll need 2 litres of gearbox oil; a pair of rubber gloves (unless you prefer the spare bed), an 8mm Socket/Ring Spanner; an 8mm Allen Key; something to catch the old oil in; and tool/method for refilling the gearbox. I used one of these:



It's a 500ml 'Silverline' Oil Gun, basically a big syringe, which makes things very easy. About £8.

For best practice, you should also renew your gearbox plug seals, which involves buying 2 new plugs from BMW. About £4 each. Take the last 8 digits of your chassis number into your local friendly parts dept to make sure you get the correct items.

The oil BMW recommend is made by Castrol, but I wanted to improve a slightly notchy gearchange I was suffering, so went for 2 litres of Redline MTL, as recommended by Redline (and Blackbmw116 on here) for notchy E Series BMW manuals.
EDIT: For My F Series M135i (which requires LT-5), I went with 2 x Febi Bilstein 39070 , as recommended by Opie Oils. Highly recommended.

Start by removing the eight 8mm screws with secure the transmission portion of the undertray. The under tray will now be loose, but will require a 45 degree twist toward the OSR to drop from the car.

Under-tray unscrewed, just before 'twist' removal:
Gearbox1.jpg


You'll now have a good view of the gearbox. Have a quick look at your new plugs, this will help you identify the Fill and Drain Plugs on your casing (and also how long those threads are for the next stage). Bear cleanliness in mind too, you don't want to knock any crud inside at any stage, or you could do more harm than good.

Fill & Drain Plugs:
Gearbox2.jpg


Slacken the top Fill Plug first. Don't remove it yet though. If you remove the Drain Plug first, and have difficulty in removing the Fill Plug, you'll be left stranded with a car with no oil in her, and a headache! (thanks Anthony) Pop your gloves on (old gear oil is nasty stinky stuff), and with oil catch-can/tray in hand, remove the Drain Plug. As you've left the Fill Plug loose but still in it's hole, the oil won't come rushing out. My old oil was like black water, no wonder my change felt crunchy, 'sealed for life' my arse. Sealed to die, more like it. Once you've lost about a litre and a half, take the Fill Plug out, and go and have a cuppa, to let it drain for a while.

Nice brew? Good. Now it's refill time. Gloves back on, and fit a new Drain Plug in the bottom of your box. The seal does the work, not the Plug, so there's no need to go swinging off the Allen key with a great big long bar! Fill the gearbox with roughly 1.6 litres of nice new oil. I simply sucked it out of the bottle, and blew it into the fill hole. When it's full, it will just start trickling out the fill hole.

Refilling with Redline MTL via Oil Gun Syringe:
Gearbox3.jpg


Now you just need to refit the Fill Plug, and replace the undertray. Again, no need to go crazy when torquing up the 8mm undertray screws.

If you went with the Redline MTL, go and enjoy your new smoother gearchange. The Castrol camp only get to feel smug about increasing the longevity of the box I'm afraid.
 
See less See more
4
#4 ·
Many thanks - planning to do mine in a couple of weeks along with a stash of other stuff, so this will certainly help!

EDIT: 23rd Oct - completed gearbox oil change this weekend, your guide certainly helped and I can't recommend the Silverline gun enough, it made this a very very easy job.
 
#17 ·
Hi,

Just did the gearbox on my 118d on the weekend. However when I took the fill plug I noticed it had a green seal on the nut. (See attached). The new nuts supplied by BMW ( didnt have these seals on them. They costed around £9 a pop too. So I decided to just clean the old nuts and add them back in.

Other than that Marco's "how to" is spot on....

Regards

 
#26 ·
marco_polo said:
Don't know anything about Auto's, I'm not a fan.

LittleJohno might know?
Just read this I specialised in manuals but autos are very delicate and aren't as simple a matter as just dipping the stick many need to be in a certain gear or park to fill the torque converter.
They also have filters due to the bands wearing the oil can become contaminated so re any warranty issues chwck with th dealer what they recommend.
But anyone can pm for advice if I know ill tell you :grin:

Sent from my GT-I9300 using Tapatalk 2
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top