what the best gearbox oil for a 1987 m3 as having rear seal changed as leaking and was just wondering what oil to put in . is there any special sort to use ???? i have been told not use any synthetic oils or it will wear like ...
thanks alex
e30 m3 gearbox oil???
Moderator: martauto
-
GermanGorilla
- E30 Zone Regular

- Posts: 528
- Joined: Mon Feb 07, 2005 11:00 pm
HI,
Millers 'BM' Range for standard gearbox use CRX 80W90
or,
Castrol EP 80/90 Gear Oil
or,
ZF make a gearbox oil, just can not find its reference, but its also 80/90.
Synthetic is good, but not for the sort of gearbox you using.
Hope that helps,
Regards,
The Gorilla.
Millers 'BM' Range for standard gearbox use CRX 80W90
or,
Castrol EP 80/90 Gear Oil
or,
ZF make a gearbox oil, just can not find its reference, but its also 80/90.
Synthetic is good, but not for the sort of gearbox you using.
Hope that helps,
Regards,
The Gorilla.
-
alexm3uk
- E30 Zone Regular

- Posts: 361
- Joined: Sat Jul 23, 2005 11:00 pm
- Location: orpington,kent
thanks Gorilla i've been told 75/90 dont think that matters 80/90 should be just fine
alexm3uk
alexm3uk
-
Demlotcrew
- E30 Zone Team Member

- Posts: 13329
- Joined: Mon Dec 20, 2004 11:00 pm
- Location: East Anglia
Why is fylly synthetic no good for the S14 gearbox?
Andrew
Andrew
-
GermanGorilla
- E30 Zone Regular

- Posts: 528
- Joined: Mon Feb 07, 2005 11:00 pm
Hi,
I do not think anybody said that Synthetic Oil was bad for the S14 Gearbox from new.
The question put was that a ring seal was being replaced, not that the gearbox was being totally rebuilt.
I have always been lead to believe that from new, or at a major rebuild, synthetic fine, but with a fair number of miles on, then non-synthetic seems to do better.
Regards,
The Gorilla.
I do not think anybody said that Synthetic Oil was bad for the S14 Gearbox from new.
The question put was that a ring seal was being replaced, not that the gearbox was being totally rebuilt.
I have always been lead to believe that from new, or at a major rebuild, synthetic fine, but with a fair number of miles on, then non-synthetic seems to do better.
Regards,
The Gorilla.
-
GermanGorilla
- E30 Zone Regular

- Posts: 528
- Joined: Mon Feb 07, 2005 11:00 pm
Hi,
Bit off thread, but I have also been told by a couple of S14 Engine Builders, that when they rebuild S14 Engines, they recommend that they are run in on just ordinary normal 10 - 40 engine oil, and then flushed out, and then run on the synthetic.
This stems from the days when BMW used to make sure the engine blocks had done 80-90,000 miles plus before using the engine blocks for building up the 1.5 ltr F1 Turbo engines.
They had far less failures with very used blocks.
Regards,
The Gorilla.
Bit off thread, but I have also been told by a couple of S14 Engine Builders, that when they rebuild S14 Engines, they recommend that they are run in on just ordinary normal 10 - 40 engine oil, and then flushed out, and then run on the synthetic.
This stems from the days when BMW used to make sure the engine blocks had done 80-90,000 miles plus before using the engine blocks for building up the 1.5 ltr F1 Turbo engines.
They had far less failures with very used blocks.
Regards,
The Gorilla.
-
Demlotcrew
- E30 Zone Team Member

- Posts: 13329
- Joined: Mon Dec 20, 2004 11:00 pm
- Location: East Anglia
Thats because all of the casting imperfection at the microscopic level had been 'worked' out while in general use in the NA form.GermanGorilla wrote:This stems from the days when BMW used to make sure the engine blocks had done 80-90,000 miles plus before using the engine blocks for building up the 1.5 ltr F1 Turbo engines.
They had far less failures with very used blocks.
Regards,
The Gorilla.
Reason i ask is that i have been using fully synth in my box 75w90 and the first gear is getting noisy )its really pissing me off now)
Andrew

