LM1 gearbox breather

[RobertK]

Hi,

My 1977 le Mans has started to push quite a lot of oil out the gearbox breather.  Too much to be just ignored.  I thought I'd probably overfilled it so I drained the oil and refilled it it with the correct amount (750 ml) and grade (80W90) but it's still coming out even after a short ride (20 miles) at moderate pace.  The gearbox works fine and there are no untoward noises. The breather is routed backwards and up to the frame rail which I think is correct.  The bike's recently passed the 100 000 mile mark and the gearbox was overhauled professionally about 20 years and 50 000 miles ago.  Any suggestions or advice welcome.  Thanks.

[spmoto]

The late great Manfred Hecht of Raceco in Brooklyn NY recommended 650cc in the Transmission. That's what I ran in all my big block Guzzi's for the past 45 years. Never had an issue. Steve M

[Tom]

I stuck a hotel shampoo bottle with hose up underneath the seat.  The bottle has a small hole to vent air.  Hose clamp on the vent and bottle.  Oil and mist condensation drains back into the trans vent. 

[nc43bsa]

Just curious, but where does 650cc of oil come to in relation to the shafts?

[Don G]

Did the transmission ever have shockproof heavy oil in it? (pink milk shake) One of my Eldorado's had that in it, drained it out and refilled with Dino 80-90, of course it blew out of the vent due to being overfilled because the pink stuff was still in the case.  DonG