Recomended "State of the Art" lubricants, grease and fluids

[mariodschy]

I am looking for the right lubricants, what i've found is:

Engine: SAE 20W 50 (temperate climates) or SAE 10W 40 (cold climates)
Gearbox: EP80
Diff: EP90
Stromberg: Damper oil SAE 20W 50
Steering, probshaft, trunnion,...: standard grease should be ok
hubs: high temperature grease whit graphite for better fail-safe features
Cooling system: ???
Clutch: Same as in brake system (i'll change to DOT 5 silicone, because of the fit and forget advantage)
Brake: DOT 3.1 or 4.1 (i'll change to DOT 5 silicone, because of the fit and forget advantage)

What are your experiences and what are your recommendations?
Thanks.

[Lotus fan]

Silicone brake fluid is NOT recommended.

This is what I was told when I picked up my refurbished brake calipers from Classicar Automotive.

Ian.

[gherlt]

Once you use DOT5 in, in case you want to change, you have to clean all through and eliminate any remainder.
DOT5 is not compatible with anything else.
If you want to use something "better", use DOT 5.1, which is basically a DOT4 with a very high "wet" (3,5 % water) boiling point (? 180?C) and it gets "wet" slower.
And DOT 5.1 is compatible with DOT3/4, you should not mix it, but you do not need to fully extract an old brake fluid when putting 5.1 in.

[ecamiel]

I speak from direct experience
Definitely do NOT use silicone fluid in brake or clutch. It becomes "soft" at hi temp, fades, even in clutch slave cylinder. Use non silicone 5.1 for anti-fade characteristics.

For motor oil use a hi zinc content oil. I use Mobil 1 "Extended Performance" (https://mobiloil.com/en/motor-oils/synthetic) for it's hi zinc content on the street and Mobil 1 Racing or Redline on the track.
If it's a street motor with 160 0r 180 degree thermostat I would use 10/40, not 20/50 in spirited street driving in normal summer weather.

Redline in the Tranny greatly improved shifting in my car and I use it in the diff (different formula- check for the hypoid lube ) as well

Eric
64 S1 Hart
CT, USA

[Tahoe]

...old break fluid ....

The brake fluid will be a break fluid.

[Galwaylotus]

Although silicone brake fluid sounds great at first glance, it is definitely the wrong thing to use in a performance or classic brake system. There are two main reasons:

Silicone fluid goes "spongy" especially as temperature rises so the harder you work your brakes the worse it gets.

A "closed circuit" brake system as in the Elan and any other automotive system of which I am aware will still take in water vapour due to the vacuum pulled at various parts of the cycle. This moisture is absorbed in a glycol based fluid (DOT3, 4 or 5.1) but not in silicone fluid (DOT5) so it condenses and settles to low points in the system where it will corrode metal parts.

As most classic cars do not do high annual mileage that can result in a lethal situation especially if the brake system is as the originally designed single circuit system where a failure results in zero primary braking.

"Fit and forget" is absolutely the wrong philosophy to use for brake fluid no matter which type is used.

[Galwaylotus]

Regarding coolant, stay away from the "Long Life" types due to incompatibility with the metal chemistry in the Elan system.

Millers makes a good 20w-50 oil that meets Lotus Twin Cam requirements. It's not that expensive and tends to leak less than the synthetic oil alternatives. The Twin Cam was designed for this type of oil so bearing clearances are appropriate for its use.

[StressCraxx]

I speak from direct experience
......Redline in the Tranny greatly improved shifting in my car and I use it in the diff (different formula- check for the hypoid lube ) as well

Eric
64 S1 Hart
CT, USA

Hello Eric,

Which Redline product did you use in the transmission? I tried the Redline MTL (Manual Transmission Lube) and the synchros did not like it. I put 80w90 valvoline synthetic and it worked fine.

What product did you use in the diff?

Thank you!

Regards,
Dan Wise

[rgh0]

Hi Dan

If Redline MTL did not work in your gear box then there is some problem with your box

cheers
Rohan

[StressCraxx]

Hi Dan

If Redline MTL did not work in your gear box then there is some problem with your box

cheers
Rohan

That's what I thought at the time. I think the MTL I used might have been too light, 75W80 which was the original grade.

Gearbox has been fine with the Valvoline for over 15 years. Perhaps I should try a different flavor of Redline next time.

[mbell]

Refine do two favors of mtl, mtl (70/80) and mt-90 (75/90).

I put standard mtl in the lotus 5 speed box but yet to drive it. Have some mt-90 on the shelf for the daily driver.