Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Greasing My nipples !

Ray, a quick google tells me that chainsaw oil is SAE30 grade oil which is probably too thin however the oil's anti-fling properties are potentially useful and might offset the oil's low viscous rating. If there's an oil technologist out there, I'd be interested in his or her input.

EP90 I have heard of used but SAE 30 I think will just act like engine oil

sounds a bit thin but it was engine oil before grease

When I've replaced the bushes I dribble some 90 grade down the top gallery before greasing, in the hope that it will get down to the top of the upper bush, (having pre-greased the bushes before refitting). Some Triumphs used gear oil in the lower trunnions - Herald/Spitfire TRs as I recall. All I would be cautious about is that some hypo oils are said to erode yellow metal.
The other unusual thing about the Morgan lower grease nipple is that it enters the stub axle above the lower bush, whereas MG grease nipples go directly into the bush. Obviously the challenge there is that when pressing in a new bush you also have to align the pre-drilled hole with the grease channel. At least with Morgan you don't have to bother with that.
There is also a hydraulic 'lock' effect when you pump the kingpin up and down in the stub, because with the grease nipple removed, grease emerges from the hole, so it seems that with the nipple in place, grease may be forced down the channels in the bushes to some extent.
For a while there was no top nipple in the upper 'lube' bolt, so there must have been some confidence that grease would also be forced up into the upper bush.

SAE30 is too thin and I wouldn't recommend it. SAE99 or thicker.

I'm getting a bit confused here. Aren't SAE viscosities for engine and gear oils different. I always thought that SAE 90 gear oil was similar to SAE 40/50 engine oil???

If so SAE 30 engine oil would be similar to SAE 80/85 gear oil.

Malcolm, I've learnt something new - thank you and thanks to the power of Google and Wikipedia!

If I understand correctly, the SAE for engine oil and transmission are indeed different due to the difference in application. Using the Mark 1 eyeball test, an EP90 is more viscous than a multigrade and when used on a Morgan front suspension in concert with grease, is not of course subject to direct heat generation and so the viscosity won't alter much.

Another interesting thing that I've learnt Malcom is the I shall be careful in future to use a GL4 spec oil in my LT77 gearbox and suspension rather than GL5 as the latter potentially has additives that may corrode yellow metals such as phosphor bronze.

In my TR4 (which I've owned since 1974) I originally used 20/50 engine oil in the overdrive gearbox. Apparently ordinary multigrade engine oil can froth (detergent?) so people seem to use either a straight 40 oil (Penrite do one for gearboxes), or EP90 GL4 spec gear oil which is what I now use.

But in my LT77 I'm sure that I use ATF?

Hi Malcolm. The EP refers to the Extreme Pressure additives in gear oil that needs to withstand sheer so my natural inclination is to use EP oil in transmissions other than in an LSD axle.mI could never bring myself to use the factory recommended ATF which is an thin as Red Barrel. I was recommended to use Castrol SMX (or whatever it is now) synthetic oil. The gearbox oil pump is a tad limited in capabaility and apparently heavier oil can challenge the pump and render it u/s; improved apparently on the R380 gearbox.

Good job I didn't start a thread on filling the car with petrol ehh