Oil for Ferret Fluid Coupling?

[Richard Farrant]

Originally Posted by LRDG

Thanks, Richard. That's a bit disappointing. I really wanted to get some thinner oil in there because right now she almost stalls at idle when first or second gear is engaged from neutral. I've got the idle mixture screws set on the lean side so I'll try setting them a bit richer to see if that helps. The idle is around 400 rpm and I can change forward/reverse quietly at that rpm so I'd like to keep it low.

She runs too cool as well. The new thermostat may improve the idle stability.

We have a spare engine and gearbox so I'll take a look just to see where the fluid coupling oil would drain out of the bell housing and to confirm I can't get a drain trough up through the gearbox drain hatch to direct the oil. The oil could be drained quite slowly by rotating the open fill plug hole gradually downwards.

Also I might be able to suck some oil out with small bore tubing through the fill plug.

I think your idle at 400rpm is a bit slow, you may find the regulator is cutting in and out at that speed too. I find it best around 550. Shifting from forward to reverse has to be done in one swift movement and can be done without it being at 400, but you need to select and engage Neutral. Also, never leave the engine running in gear while stationary for a period as oil will overheat.

You say you think the engine is running too cool, let me know what temp it is showing on the gauge please.

Regarding draining oil, if you don't want a mess then the only way is to pull the gearbox back from the engine.

regards, Richard