Most of my racecars had a raised filler plug, so we'd get about 2 litres in the housings, with baffled axle tubes to stop the oil running up the tubes. Basically, fill it til you can't get any more in.

well that makes life easy if it is threaded, i thought it was similar to the gearbox breather, how much oil would you put in b310gx?

I'm pretty sure even the H145 diff has a threaded breather. I use the right angle outlet from a fuel pump, connect some clear plastic hose to it & either run it into a bottle in the boot, or usually make a large loop so any oil coming out under cornering will run back into the diff. I point the fuel fitting 'uphill', & make a loop which comes back to the fitting, then use a large cable tie to attach the hose to the fitting & close off the end, so only a little is lost if it gets to the end of the hose. I've seen some cars where the hose is run into the cabin, so you can smell if the diff get hot, but to me all you smell is diff oil, constantly.

H145 with a Nismo lsd.
Definetly not as growly as previously with the higher oil level.
Even 1.2 litres is not a huge amount I would have thought?

.8 to 1.2 sounds like a lot, thats 150% full

or in real terms if the diff is 1/2 full after a normal top up you have it up to 3/4, the axle tubes would be nearly completely full

most corners you would not be accelerating in either, so the diff is not under load at this time, the only concern would be particularly long sweepers that you do actually accelerate on

the standard diff im pretty sure has axle baffles in it doesnt it?

are you running h145 or h165?

Thanks RC,
Best to keep plenty of the good stuff in the diff as with the high cornering forces generated it gives the center hell trough sweeping corners. Only gone from .8 upto 1.2 litres.
Seems a bit odd that Nissan would use plastic, especially in that era?
Cheers
Dave

pretty sure its plastic press fit in, the head usually snaps off before the rest of it will come out, perhaps you don't need to overfill the diff?

Guys,
Raced the SSS for the first time in a year last weekend down at Levels raceway in Timaru and had a ball...
After checking the car over on Sunday it appears that ( after deliberatly overfilling the diff ) some of the diff oil is coming out of the breather and spilling down the sides.
Now I remember back when I used to race XU1's we had the same issue and simply undid the breather on the diff and screwed in a fitting that allowed us to run a hose upto a breather bottle that was in the boot thus giving any oil that got pushed/ pressured out a chance to drain back in.
So, can anyone tell me the little breather on the top of the diff housing ( close to the head ) - does this unscrew or do I need to take to it with implements of torture?
Cheers
Dave