Hi

I changed the gearbox oil on my MY03 STI today.
I removed both drain plugs and renewed the copper washers.

The handbook stated that 4.1 litres was needed.
I put in less than 4 litres and still the oil level is above the FULL marker on the dipstick.

Will this cause any problems?
Should I drain a small amount out?

Thanks
Steve

 

It won't cause any problems, the reason is that it happens is you seldom manage to drain all the oil from the box.

 

i was advised it is best to slightly overfill gearbox,if memory serves correct by about 0.25-0.5 litres something to do with keeping fifth covered i think?

 

6 speed box has oil pump to transfer oil to a tray at top of box so johnny's advice only applies to 5 speed. I know to my cost as I had input shaft oil seal fail and tipped 2L of oil on my clutch. £12 for oil seal and £400 for labour and clutch repair to say nothing of the stink of that much gearbox oil on the exhaust. DOH.

 

Are you putting the seal failure to being over filled? The seal in question isn't under oil pressure, and you would need to overfill it by another 4 litres of so to bring the oil level up enough to submerge the oil seal!

 

No, not due to overfilling. Sorry if I said something misleading. Was just making the point that there was no advantage in overfilling a 6 speed.

The seal died of prematurely at 5yr/50k and was just bad luck, little springy thing running round the outside of the seal fell off (track day abuse and paddle clutch no doubt helped). I understand it is not under pressure but it sure comes out fairly quick if seal falls apart. Good news is that the underside of my car is well rustproofed now.

 

UK Classic 5 speeds at least have an oil pump, anything with different front and rear ratios (and a 1.1:1 drop gear set) appears to.

Simon

 

No they don't. Not a "pump" in the conventional sense, they have a system to distribute oil, but the 6 speed is totally different in that it has an actual pump, filter and sump arrangement with pressurised oiling.

 

Some TY 755 Foresters; yes, but Impreza TY752 / 754; No .

David APi

 

I think that pump is only to circulate oil through the cooler, rather than the bearings etc?

 

That's right, I have never seen a road going manual box on any car with an oil pressure feed system. They are always just to pump oil through some sort of heat exchanger.

In my defence, the discussion was about pumps, not about what they did

David

 

FWIW:
The big Porsche turbos had a pump to squirt oil into meshing gears and to get oil to an on-board cooler, the RSR's to an external cooler.
My box has a small pump to circulate the oil through a small coiled tube cooler.
All this boosted the reliability of the old 915 box no end till the G50 came along in 88.