Changed Diff oil today

[Bazoz4]

After ringing round all my local auto shops looking for Diff and Gearbox oil none had specs for my oil they said BMW would not disclose specs for these oils, so after reading many solutions from various forums Redline came up as a favourite, so after googling i gave them a call in Coventry and spoke to a techy guy who kindly told me what i needed and the quantities, he gave me the number of Demon Tweaks in north Wales who are one of their distributors I spoke to a guy there told him i need two U.S. quarts of D4 ATF for Gearbox and Two U.S. quarts of their 75 w 90 for Diff both oils are fully Synthetic. £75 quid in all he said you will have then by following day and they did arrive as stated.
After a warm up run i got the car jacked up and be dammed there was no drain plug so sucking out with hand suction pump was a pain in the butt. refilled till oil started running from filler plug replaced filler bung with new seal and job was done. the old fluid was a dark grey.
P.S. my gearbox is manual and on the container was D4 ATF is good for manual and auto transmission. went for a trail run after cleaning myself up and things ran smoothly, I felt quite chuffed with my labours...Next job when weather suites is changing gearbox oil.car will be running on new blood all round. Cheers all Barry

[Paulwirral]

If your changing the gearbox oil , I'm assuming it has a drain plug as I've never looked on mine , but always remove the filler bung first , it's not unheard of to drop the oil then not be able to remove the filler bung !
I speak from experience but fortunately it was a Nissan cabstar tipper truck so all I had to do was raise the tipper bed and pull the top of the box off ,
I changed the oil and fitted an earls braided hose to my old 3mc coupe and the difference was night and day .

[Bazoz4]

Yes it does have both but sound advise, thanks Paul Cheers Barry

[Bazoz4]

After short warm up run Gearbox oil replaced today , filler plug loosened first then drain plug removed with 14 mm allen socket no probs left her to drip whilst i had cuppa and a ciggy, then filled back up with hand pump which cost £5-20p bit messy but filled till new oil started to trickle from filler hole, new green rubber seals fitted to both plugs prior to refitting and job was done. went for test run and gear changing was silky smooth. Now engine, gearbox and diff oils have all been changed at 11,000 miles, I intend keeping the Z for a long time, my moto is look after them and they will look after you. all were relatively simple tasks so go for it.
All the best Barry
P.S. arrived today SGS 3 ton low profile trolley jack Length 700mm Lifting height 98mm to 535mm £131-00 free del. Model no. TJ3LP.

[igeak691]

Does changing the diff oil affect the shifts? Am I mistaken in thinking the diff oil and transmission oil are two separate things to change?

[SUUNTOBOB]

After short warm up run Gearbox oil replaced today , filler plug loosened first then drain plug removed with 14 mm allen socket no probs left her to drip whilst i had cuppa and a ciggy, then filled back up with hand pump which cost £5-20p bit messy but filled till new oil started to trickle from filler hole, new green rubber seals fitted to both plugs prior to refitting and job was done. went for test run and gear changing was silky smooth. Now engine, gearbox and diff oils have all been changed at 11,000 miles, I intend keeping the Z for a long time, my moto is look after them and they will look after you. all were relatively simple tasks so go for it.
All the best Barry
P.S. arrived today SGS 3 ton low profile trolley jack Length 700mm Lifting height 98mm to 535mm £131-00 free del. Model no. TJ3LP.

surely you mean 110,000 miles?

[YR53]

During my Z4rebuild project. Autologic nr Hull changed my Diff and Gearbox oil. Big difference on gear change. Much smoother and less sticky.