gearbox oil

[jellywrestler]

got a bike that lists 30 weight engine oil, mid sixties four stroke twin, we've moved on since then, what alternatives should i look at to use?

[Voltaire]

I use EP 90 in the BMW's, but there are no bush's in them, you have to check the label GL4 and GL5 harms " yellow metals"

You may need to check that as its from memory.

[sidecar bob]

is it a combined unit, or stand alone gearbox. Wet or dry clutch?

[jellywrestler]

is it a combined unit, or stand alone gearbox. Wet or dry clutch?

1966 kawasaki W1 preunit, wet clutch in a primary chaincase, pretty much identical to a bsa of the time. having a bit of an issue with gear selection so first thing is an oil change methinks

[T.W.R]

Try some Castrol Classic XL30 or ST90 ( it's API GL-3)

EP90 is actually GL-4

[AllanB]

1966 kawasaki W1 preunit

Nice score there. Photos please.

[Voltaire]

Try some Castrol Classic XL30 or ST90 ( it's API GL-3)

EP90 is actually GL-4

I forgot the , was doing the Vespa recently and its got bushes. Oil that is not black and smelly makes it a lot smoother

[jellywrestler]

I forgot the , was doing the Vespa recently and its got bushes. Oil that is not black and smelly makes it a lot smoother

ended up using the same shit as i use in my vincent gearbox, made sense to me.

[T.W.R]

I forgot the , was doing the Vespa recently and its got bushes. Oil that is not black and smelly makes it a lot smoother

Yeah the XL30 & ST 90 are specifically designed for early style gearboxes etc with straight cut & helical gears the XL30 is a 20w too and both GL-3
GL-4 & 5 are for hypoid and the such like

[Grumph]

ended up using the same shit as i use in my vincent gearbox, made sense to me.

I'll bite - what do you use in a Vin box now ? EP90 ?

If the kawasaki clutch and primary have their own oil, I'd use ATF in that side.

[sidecar bob]

I'll bite - what do you use in a Vin box now ? EP90 ?

If the kawasaki clutch and primary have their own oil, I'd use ATF in that side.

Yep, I'm in the ATF camp too. Everything in that gearbox is in an auto, plus heaps more & the auto works the oil a lot harder.
ATF is way more than up to the job.

[T.W.R]

A 50yr old long throw 4spd gearbox that's been running a heavier weight oil isn't got to like ATF....ATF is only equivalent to roughly 10w.
If it's been completely refurbished with new components & seals then yeah maybe, but it wasn't designed for it and 50yrs of wear & tear have got used to something with a bit of guts to it

[sidecar bob]

A 50yr old long throw 4spd gearbox that's been running a heavier weight oil isn't got to like ATF....ATF is only equivalent to roughly 10w.
If it's been completely refurbished with new components & seals then yeah maybe, but it wasn't designed for it and 50yrs of wear & tear have got used to something with a bit of guts to it

I think I have a better idea on your age now. Oil & guts in the same context.
It's a cog box, not an internal combustion engine.
In the late '80's the Holden dealer parts manager phoned me to ask how I was fixing all the commodore 4 five speed gearboxes without fitting new synchros. The answer was, fill them with ATF.

[T.W.R]

I think I have a better idea on your age now. Oil & guts in the same context.
It's a cog box, not an internal combustion engine.
In the late '80's the Holden dealer parts manager phoned me to ask how I was fixing commodore 4 five speed gearboxes without fitting new synchros. The answer was, fill them with ATF.

wasn't aware the correct terminology was a prerequisite for the thread

Common door 4cyl were a POS anyhow quickest fix was a litre of fuel poured around the interior & a match thrown in to get things underway

[Grumph]

A 50yr old long throw 4spd gearbox that's been running a heavier weight oil isn't got to like ATF....ATF is only equivalent to roughly 10w.
If it's been completely refurbished with new components & seals then yeah maybe, but it wasn't designed for it and 50yrs of wear & tear have got used to something with a bit of guts to it

1/ I didn't actually say to use ATF in the Vin box - just the clutch and primary of the Kawasaki if they were a separate compartment. BTW I suspect the kawa version of the BSA box has a few more rolling element bearings...

2/ SAE rating is irrelevant - EP90 ain't 90 weight. ATF is formulated for high temps and pressures.

3/ I've used atf in plenty of boxes since the 70's. It was the standard fix for slipping wet clutches in race 2 strokes and is still my first choice for a race post classic 2T engine.