Gearbox oil change

domsz4 · Post by **domsz4** » Sat Sep 16, 2023 1:04 pm

Are there any how-to’s for doing a gearbox oil change on the manual 6 speed box? Is it complicated

enuff_zed · Post by **enuff_zed** » Sat Sep 16, 2023 1:22 pm

domsz4 wrote: ↑Sat Sep 16, 2023 1:04 pm Are there any how-to’s for doing a gearbox oil change on the manual 6 speed box? Is it complicated

Pretty easy tbh.
Drain plug out (1). Fill plug out (2). Drain the old oil. Drain plug back in (1).
Fill to spill. Fill plug back in (2).

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smorris_12 · Post by **smorris_12** » Sat Sep 16, 2023 1:26 pm

Same as any other gearbox really. Undo fill plug followed by drain plug (not the other way round), one underneath, one up on the side. Put drain plug back, wangle oil uphill into fill hole[1] until it starts coming out again.

Box takes about 1.5 litres (can't remember spec.)

[1] Choice of using the 1l squirty bottles with pull out nozzle the oil comes in or a long length of pipe that fits in the filler and a funnel attached to the other end.

enuff_zed · Post by **enuff_zed** » Sat Sep 16, 2023 1:45 pm

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smorris_12 · Post by **smorris_12** » Sat Sep 16, 2023 2:04 pm

Just had a look and I used Comma 75W GL-4 spec from Halfords. Some people use ATF, some MTF.

domsz4 · Post by **domsz4** » Sat Sep 16, 2023 2:23 pm

Oh yeah

deffo easy lol.

For some reason I had the impression there wasn’t a drain plug.

Might as well add that to the list to do.

Also want to do the brake fluid as that’s not been done for a good few yrs

smorris_12 · Post by **smorris_12** » Sat Sep 16, 2023 2:47 pm

The very late diffs (2007 or 8 onwards) came without a drain plug.

Nictrix · Post by **Nictrix** » Sat Sep 16, 2023 3:05 pm

As Smorris says though, take the fill plug out first. If you drain the oil first and cant get the fill plug out you are kinda stuffed.

FunkyGBrown · Post by **FunkyGBrown** » Sat Sep 16, 2023 3:52 pm

What oils are people using? 136k on mine and no idea if it's ever been changed.

domsz4 · Post by **domsz4** » Sat Sep 16, 2023 7:52 pm

FunkyGBrown wrote: ↑Sat Sep 16, 2023 3:52 pm What oils are people using? 136k on mine and no idea if it's ever been changed.

Kinda my thoughts too

Good call on the fill plug first..

chanlon1 · Post by **chanlon1** » Sat Sep 16, 2023 9:48 pm

Do you need to put new plugs in or can you reuse the existing ones?

smorris_12 · Post by **smorris_12** » Sun Sep 17, 2023 9:29 am

Yes, just reuse the same ones.

NaweedMustafa · Post by **NaweedMustafa** » Sun Sep 17, 2023 1:26 pm

260,000 Km's and I didn't see any mention of gearbox oil change on mine from the previous owner invoices. Just got the job done with Motul 75w80 MTF LT. Not a single bit of notchiness on the shifts. Not super hard to tackle

chanlon1 · Post by **chanlon1** » Sun Sep 17, 2023 3:38 pm

I just watched this video and the guy talks about ‘shocking’ the two plugs before trying to undo them. Says the heads can strip easily.
Anyone care to comment?

https://youtu.be/BcULW_T3VHk?si=Y1aVmmRhc9RnQtgl

smorris_12 · Post by **smorris_12** » Sun Sep 17, 2023 7:08 pm

Because they're large flange jobs they can really bed down and need a jolly good heave to move them. If the socket bit isn't fully home or a good fit then there's a danger of ripping the socket out of the plug. Did that with the fill plug of the X5 once and after I'd drained it. Had to thump it round with a chisel. Whoops.

On the other hand, did the 3er and Z4 without batting an eyelid.

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