From another thread on greases for Jeeps.
Originally Posted by CJeep
I actually like Lucas Red & Tacky. Good stuff. I can't say how it compares to marine grease, I'm gonna have to try that soon.
How does Lucas Red and Tacky compare to Marine grease? According to my local Napa Auto store that sells both, they are both highly resistant to fresh water, and the marine grease is also highly resistant to salt water. They don't know if the Lucas is resistant to salt water or not, though I think I read "Marine uses" on the Lucas tube.
They also said that the Lucas has a higher shock load ability than Marine grease does, and for that reason they prefer Lucas Red and Tacky for 4x4s around here (since we don't have salt water, but we do have lots of fresh water, and it has a higher shock load). They and the local logging supply store, and our local fresh water marine store (Columbia River) all recommended red grease over marine for fresh water applications because of higher shock load ability. In fact, our local marine store doesn't even sell marine grease (salt water marine grease), they only sell red grease (which they say is best for high work load, high shock, high friction conditions in wet climates (but they meant fresh water, not salt water). That's basically the same things Napa told me and they sell 3 brands of red grease (including Lucas) and they sell one brand of Marine grease.
So what's better to use on a car chassis? I don't know. Based on what they've told me, the marine would be better if you live near the ocean with salt water because it's salt and water resistant. But if you live inland where it's wet, but NOT salty, then red grease (ideally Lucas) is best because of higher shock load ability and it's just as resistant to fresh water as marine grease is. However, they (Napa) then added that the higher resistance to shock loads that red grease has is mainly a benefit in Catepillar tractors. For a Jeep, they said, the marine greases have a high enough shock load ability.
So bottom line, if you live near ocean, I'm told the best marine grease you can get is best. If you live inland where it's wet, but not salty, then a read grease like Lucas, is theoretically best (I'm told), but marine grease would also be fine. i.e. - if you live in an inland wet area, either Lucas red grease (or other brand of red), or marine grease, are all fine for fresh water applications, and both have a high enough shock load ability for a car or Jeep chassis and wheel bearings, but for a CAT they'd only use red grease in a fresh water situation. But for a Jeep in fresh water, either Lucas Red or any brand of marine is fine.
I've be curious to hear what they'd say about a CAT at the ocean beach.
There are also synthetic marine greases. I'm guessing they might be the ultimate, but as yet I know nothing about them.
And I'm not saying what's best. I'm only saying what my local fresh water marine store, logging store, and Napa auto all told me, which seems to be in agreement with each other.
One thing I do observe is that what's best seems to be relative to our local conditions, and your local marine, logging, or auto store will be familiar with your local conditions.
So I'm in the process of learning about greases. I don't claim to know yet what's best even for me in my own climate/terrains. I certainly do NOT claim to know what is the best grease for anyone else. I'm still learning, and enjoying the process.
My understanding from Napa is that a maring grease would be best for my 4x4 needs because it's shock load ability is high enough for a Jeep (even though red grease is higher), and I might sometime drive 60 miles to the ocean beaches (where I'd defineately want marine grease).
So I'm not really sure yet, but I'm leaning toward marine (especially synthetic marine grease), but the Lucas red grease, and also that stuff Hoseclamp told me about also look attractive.