Diff fluid and gearbox fluid change

[franandsteve]

I have owned my 05 plate 2.5 Z4 for 3 years now with 82k miles.

Do I have to change the diff fluid and gearbox fluid on this model and if yes when.

 

[hopz121]

You don't have to but I would recommend it along with the coolant.

Anytime from now won't do any harm

The oil / coolant is proobaly 11 years old already

 

[andystone]

My manual seems to whine (I can hear the exhaust plus this whine), does this sound like a fluid change?

 

[buzyg]

May be an ///M thing but most seem to do those at ins ll. I certainly did

 

[srhutch]

May be an ///M thing but most seem to do those at ins ll. I certainly did

It is an ///M thing. For life in all other E85/6

 

[csquire4]

Yep, get it done.

On my 2004 3.0 manual I used some Castrol Syntrax Longlife 75w-90 for the diff (it takes about 1.5 litres) and for the gearbox Opie Oils and a lot of BMW forums recommend a 50/50 mix of Red line MTL and Red Line D4 ATF to help smooth out the notchy BMW gearbox. If your gearbox oil has never been changed you will notice the difference.

 

[Paulwirral]

If you do it yourself always remove the filler plug first , nothing like draining it then not being able to budge the filler plug thankfully when I did this it was on a small tipper truck so I had other access options

 

[csquire4]

Unless you have access to a ramp I would recommend getting a good indie to do it. To refill the gearbox you need a huge syringe type device and you have to get rid of waste oil, It'll cost you about £50 as both are drained at the same time.

 

[Ewazix]

Unless you have access to a ramp I would recommend getting a good indie to do it. To refill the gearbox you need a huge syringe type device and you have to get rid of waste oil, It'll cost you about £50 as both are drained at the same time.

+1 on using an oil extractor, I've not done the Zed but other cars have often involved jacking one side to tilt and drain the box, which is a pita.
I've got something like this which works well providing the oil isn't steaming hot!
https://oypla.com/diy/automotive/4-litre-oil-fluid-extractor-fuel-pump-syphon-transfer-4l?gclid=CjwKEAiAjcDBBRCJxouz9fWHynwSJADaJg9BhwJ-pz_0rjRjxV4G1vWVRk70bzPFGbmHQqQaFv-_3xoCBWXw_wcB&zenid=og6db07vepovhhd5g2gtfqgvn5


......... and one of these screwfix things for small jobs, but wouldn't recommend it as it's crap and can't pull more than a drop before the seal gives out :thumbsdown:
http://www.screwfix.com/p/handy-parts-hp-162-oil-change-kit-1ltr/27283?kpid=KINASEKPID&cm_mmc=GoogleLocal-_-Datafeed-_-Outdoor%20and%20Gardening&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&gclid=CjwKEAiAjcDBBRCJxouz9fWHynwSJADaJg9BusgQxIUHNvWC0nAOY1IKsTLlM9HE6y6uXLRJPKRxyBoCVfrw_wcB

 

[GuidoK]

Regarding the diff you first need to know if you have a drain plug or not. If you dont have one, you need an oil extractor to get the oil out.
If you have, you can drain it.
The gearbox always has a drain plug.
As already said for the diff you need an oil syringe to fill. (also handy for the gearbox).
Whats also difficult is to get the fill plug loose from the diff. First of all its a 14mm hex (not very common), just like the diff drain plug, but its not easily accessible. You can get in there with a traditional 14mm hex key, but a 14mm hex socket on a 1/2" drive doesnt work.
For this job I have a special tool, which is a 14mm hex bit (like those little bits for drilling machines), but on a 8mm or 10mm drive.
I put the bit in the drainplug and use a 8mm (or 10mm if you have the 10mm drive bit) gearwrench (ratchet spanner 8 or 10mm) to loosen/tighten.
So its this style of bit:
10mm drive:
http://www.ebay.co.uk/itm/14mm-HEX-KEY-BIT-ALLEN-Socket-10mm-Hex-Drive-30mm-long-/161031688526
or in 8mm drive (picture on ebay is not accurate):
http://www.ebay.co.uk/itm/14mm-Allen-Bit-Socket-5-16-30mm-Long-5-16-8mm-Drive-/302141345858

Also for the diff there seem to be 2 different style of drain plugs: plugs with an o ring seal and plugs with an aluminium crush washer.
On the pre facelift cars the aluminium crush washer types seem to be mostly used from what Ive seen.
You're supposed to replace that aluminium crush washer but I've never had any problems with leaking if you dont (and I've had my diff of the car quite a few times...)

The gearbox drain/fillplugs are always with o-ring seal (o ring sits fixed in the cap of the plug). Again you're supposed to replace them but I've had no problem with re-using them also. But do inspect if the o-ring is damaged, and always put a drop of oil on that o-ring before installing so it doesnt tear up when tightening.

If you rent a car lift and if they have a drain pan its easy to do yourself. The most difficult part is to get the right tools to do it.
To show you what kind of access you have to the rear diff fill plug:

This is me filling it up with an oil syringe and a hose attatched to it.
If you want to extract the fluid (so if you have a diff with no drain plug) you need a thinner, more flexible hose (but that always comes with the extractor)

But you can see that you cant get that drain plug out with 1/2" socket sets. so a 14mm allen hex 1/2" socket wont work, even with a joint attatced to that.

In this pic not only the rear antiroll bar is removed (not necessary for this procedure), but also the lower tension bars. I'm not sure if you have to remove those, but if you do, the TIS manual suggests to replace the bolts because they are tension bolts (60Nm plus 90deg). Again I've never replaced those bolts and havent had problems yet. I might replace them once in the future because I had those bars off 10+ times.