Trunnions.......Oil or grease????

I would be willing to bet that this topic has had much discussion in the past but since I'm a new member and haven't seen it I would like to get thoughts from the group. I have been working on a Spit 1500 resto-mod for the last 2 years and I'm getting very close to that first drive. When I completed the front end rebuild I was unsure what lube to use on the trunnions. I found on other forum sites the opinion is a high performance grease is more than adequate instead of oil. I used Mobil 28 which is a high quality product. I'm not driving the car but will be soon . Do I need to clean out the grease and oil the trunnions or will I be OK ?

You'll probably be ok, but many still advocate the use of 90 weight oil instead of grease. True, greases don't "dry out" like they used to, so they'll probably continue to flow. But one interesting argument I've heard in favor of oil is that the oil might be less likely to carry bits of dirt in suspension; rather it would let any particles settle out. Whichever you choose, the important thing is to maintain a regular schedule of lubrication of the trunnions. Do NOT let them get dry. Worn trunnions are no fun; worse, snapped vertical links are DEFINITELY no fun! :frown:

As you know, the trunnions are threaded, as is the bottom of the vertical link to change the geometry of the wheel as you steer the car. Because they are threaded, the vertical link will move up and down in the trunnion as the wheel is turned. The up and down movement, however so slight, is enough to pump the oil, or if you wish, allow the oil to flow within the trunnion. The very much higher viscosity of grease does not allow this to happen.

At least, that is my two cents on the issue.

All this said, I have in the past just greased them.

I too had this dilema of using oil vs. grease. I finally made the decision to disassemble my trunnions and remove the grease. As others have said, the gease attracks dirt and may not flow through the threaded elements.
Oil was how the car was designed, so for now I'm sticking with it.

The factory recommended grease for the early TRs, and it seems to work well there; provided you add grease periodically as the book says. Adding grease carries the wear particles away, as well as any dirt; plus keeps it from drying out.

Gliderman8 said:

I too had this dilema of using oil vs. grease. I finally made the decision to disassemble my trunnions and remove the grease. As others have said, the gease attracks dirt and may not flow through the threaded elements.
Oil was how the car was designed, so for now I'm sticking with it.

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I am a non-mechanic Triumph owner and thus I don't
know enough to cut corners. Lord knows I've spent three years
fixing and replacing Previous Owner short cuts. So I stick
to the original specs for the car: Can't go wrong with that.

Dale (Tinster)





edit: poor typist.

Okay, so if you are to use oil, how do you "pump" it in through the "grease nipple" on the trunnion?

Mark Jones said:

Okay, so if you are to use oil, how do you "pump" it in through the "grease nipple" on the trunnion?

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Initially, you add the oil before you install the trunnion.
For maintenance they sell an oil gun with a "grease nipple"
fitting on the end. Google it, you'll find it.

dale (tinster)

OK! I'm off this thread now. Adios!!
Just my personal opinion to use oil.

I'll let the more experienced TR guys take over.

Another option is "00" grease. It's a semi-fluid grease used in agriculture for gang mowers and such and has EP properties. Try google. I have a tube but haven't used it yet. Looks to be best of both.

Mark Jones said:

Okay, so if you are to use oil, how do you "pump" it in through the "grease nipple" on the trunnion?

Click to expand...

This what I use. I bought it at a local marine store, but you can source them on the net.
The end of the gun fits into the grease nipple.

I have always used grease on my cars purely because I only had one grease gun and it was therefore easy. I just make sure that I regularly grease all of the points on the car and consider that the grease will not dry out in between applications. I make sure that the grease pumps out of the top of the trunnion each time.
A friend of mine uses oil, but has had problems with it dripping out of the grease nipple.