Gearbox and diff oil change how to?

  • Thread starter Thread starter Anonymous
  • Start date Start date
A

Anonymous

Guest
Hi folks, just ordered a load of fluids for myself and a mate to do our Zeds' diff and gearbox oils.

I've seen some posts about the location of the filler and drain plugs on the GB and from the looks of it, it's awkward to fill... question is, do we need a pump to actually get the new stuff back in??

And what about the diff?

Any help gratefully received!
 
Oh, and additionally, do we need new plugs for engine/diff/GB fluid changes?
 
I used a pump on the gearbox. I can imagine it being bloody difficult without one.
Simple to do with a pump.

The diff i did mine when it was out of the car. And the M diff is different as we know to non M s so cant help there.
 
Tip - Before you undo the drain plugs, MAKE SURE the fill plugs are loosened and not seized etc....

The last thing you want is an empty gearbox/diff that you can't refill.
 
nb67 said:
Tip - Before you undo the drain plugs, MAKE SURE the fill plugs are loosened and not seized etc....

The last thing you want is an empty gearbox/diff that you can't refill.

Thanks mate, had noted that on every thread! Appreciate the comment :thumbsup:
 
JAD said:
nb67 said:
Tip - Before you undo the drain plugs, MAKE SURE the fill plugs are loosened and not seized etc....

The last thing you want is an empty gearbox/diff that you can't refill.

Thanks mate, had noted that on every thread! Appreciate the comment :thumbsup:

I thought as much but you never know :thumbsup:
 
I think you may need a pump for the diff (although on the M I think the fillplug is on the side, not on the back). The gearbox I think you can do without. Although a pump or oil syringe can be very handy.
Also to get to the diff fillplug can be difficult. Be sure to have the proper hex.
 
Not sure on the M but gearbox is relatively easy. Drain plug below and fill plug on the side.

Diff on my car (3.0si) only has a fill plug. You either need to remove diff and take rear cover plate off (this is a big PITA) or suck out the old oil. I did this and as I didn't have a pump for it, I used a brake bleeding kit in reverse (worked quite well actually). You'll need new plugs too.
 
Diffs vary, I have a 3.0si and the diff has drain and fill plugs. Nightmare to find the P/N for new ones too. Aside from that it's pretty simple - I used a funnel and tubing to fill the box from the engine bay.
Diff I pumped to fill.
 
could not believe the difference to the gearbox when my was done a few months back..... just could not believe fluid change could make the gearbox feel that much better, REALLy enjoying the gear change quality in my car right now, its a really nice gearbox actually, it deserves alot more praise than it gets.
 
Beedub said:
could not believe the difference to the gearbox when my was done a few months back..... just could not believe fluid change could make the gearbox feel that much better, REALLy enjoying the gear change quality in my car right now, its a really nice gearbox actually, it deserves alot more praise than it gets.

Well that's damn good to know fella, thanks! Did you DIY it or get it done at a garage?
 
I'm planning to change the diff and gearbox oil in my 2003 3.0i with 6-speed manual.

I've brought the Castrol oils and a cheap pump.
41V2ZBejF3L._SY300_.jpg
I've read that you should fit new fill/drain plugs. I guess as they are hex plugs, they probably chew up easily, so I'll get some. I've seen the gearbox plugs are part 23117531356 and both a fill and drain plug are clearly shown here.
359496_x800.jpg
However, on the diff, its not clear if there is both a drain and fill plug. The list below this diagram shows qty 2 of item 4, so I guess there is.
Can anyone confirm? And do you need item 5, gasket ring?
 
Could be either. Not all have both plugs some only have one. Same with the drain plugs but you can just replace with o-ring versions.
 
I tried to look under the car last night, but its so low, you've got no chance without jacking it up.
I've ordered a full set of drain plus (x4) from www.genuineautoparts.com . If I've got too many, I'll sell whats left.
 
I did the oil changes this week. I would recommend buying new plugs, as they aren't that expensive and being allen key type, they can easily chew up trying to get them out, as mine where rusty/seized. The gearbox plugs are aluminium so can chew. The diff plus are steel, so you could re-use these and just buy new washers at 72p for the pair.

Here's a list of what I used and what it cost me, for my 2003 E85 3.0i 6-speed manual.

Gearbox
2 x BMW 23117531356 gearbox screw plug, from Genuine Autoparts - £10.18
2 x 1L Castrol Syntrans B 75W manual transmission fluid - £40.00

Differential
2 x BMW 33117525064 diff drain plug, from Genuine Autoparts - £6.56
2 x BMW 07119963355 gasket ring, from Genuine Autoparts - £0.72
2 x 1L Castrol Syntrax Longlife 75W-90 axle fluid - £27.99

Getting the lower diff drain plug out was pretty difficult as I couldn't get my allen key socket in as it was too long. Ended up making a 'tool' using a bolt head as the allen key and welding too nuts on to allow a socket to grip it. From memory the plugs need a 14mm allen key, but you'll be find if you have a short key.

I haven't noticed any real change in the gear change, which is disappointing. Its quite clunky and isn't smooth, so was expecting an improvement - but then it's 13 years old and done 110,000 miles, so maybe it can't be improved now. Still, I'm glad I've changed the oils and know its done. I would suspect it had never been done before as the plugs were the same condition as the gearbox and diff. Yet the oil wasn't as dirty as I was expecting. I suppose that's a sign of how good quality the gears and cogs are.
 
Back
Top Bottom