Wheel, Hub and Chassis Grease

[surfguitar58]

Another newbie question: What is everybody's go-to general purpose grease for general maintenance of suspension components? Castrol LM doesn't seem to be available any more. Have significant advances been made in the grease world in the last 50 years, like they have in motor oil? Are synthetics the way to go? Are there compatibility issues between old and synthetic grease?
Tom

[Pfreen]

Tom,

I don't know a lot about grease but I think the most critical grease is in the rear u-joints.  I researched this a fair amount and I now use what they recommend for their u-joints.  It is Spicer 1051.
https://spicerparts.com/parts/lubricants/automotive-performance-commercial-off-highway/spicer-ultra-premium-synthetic

I found that other u joint greases were too thin and would fling all over the place.  In fact, it flung in the bell housing hole for the starter and every time I ran the car and it got hot, the grease would liquify in the bell housing and drip oil on the garage floor.  I thought my rear seal was leaking.  However, the oil did not smell like engine or transmission oil.   I am sure glad I don’ have to pull the transmission again.

I just used a good quality bearing grease for disc brakes for the front wheel bearings.  I think disc brake grease is thicker so it doesn't get on the discs.

[BDA]

Back when I was building my car, I heard that Kendall made a really good blue grease. I had used other Kendall oils in my race car because they were recommended so I trusted their grease too. I can't say that it's better than another grease but I haven't had any problems with it. I used it on my front wheel bearings. Everywhere else I use moly grease. I am told by a college buddy who used to work for Shell Oil at what was at the time (and likely still is) the largest grease plant in the world that moly grease is the best thing for sliding friction so I use it in my trunnions. This is controversial and I'm not going to argue with anyone over my choice. The manual says to use 90 wt gear oil. It's up to you. I also use moly grease in my rack. I do this knowing that gears do not suffer from sliding friction but rolling friction (and a rack and pinion are two gears) but there is sliding friction between the rack and the pressure pad (which is admittedly probably minor compared to what happens on the rack and pinion) and also I have one grease gun and I keep moly grease in it. I use moly grease on my U-joints for the same reason.

To my knowledge there are no compatibility issues between different greases but I think it's good (and messy) practice to replace the grease rather than just add it.

This is what I do and why. I think there is a lot of room for differing opinions.

[BDA]

Tom,

I don't know a lot about grease but I think the most critical grease is in the rear u-joints.  I researched this a fair amount and I now use what they recommend for their u-joints.  It is Spicer 1051.
https://spicerparts.com/parts/lubricants/automotive-performance-commercial-off-highway/spicer-ultra-premium-synthetic

Thanks for the tip Pfreen. I may get another grease gun!

[jbcollier]

Castrol LM.  LM = lithium molybdenum.  Use a name brand lithium molybdenum grease and you’ll be fine.  More importantly is to grease often, at the very least twice a driving season for the u-joints.

Use grease rated for wheel bearings in the front wheel bearings.  As per the manual use GL4 gear oil in the trunnions and rack.

[RoddyMac]

As per the manual use GL4 gear oil in the trunnions and rack.

I thought the rack used grease, just the trunnions used GL4.

[Pfreen]

I use gear oil in the trunnions.  It can’t go anywhere since it basically an oil bath.

[jbcollier]

Grease is a mixture of a base and oil.  Traditionally the base was soap.  The oil evaporates after a, albeit long, time.  This then leaves the base which has no lubricating qualities.  If you strip and clean your rack every ten years or so, no big deal.  If not, lubing with gear oil is better.

[dakazman]

 I used the recommended lubricants Kryloc ,Royco, and Aeroshell  brands most aircraft assemblies .
AEROSHELL 33MS Lithium Moly Synthetic MIL-SPEC . A search of , grease equivalents,  will help.
Get the MSDS spec sheet for safety information.
Dakazman

[BDA]

JB's use of gear oil in his rack prompted me to ask my buddy who worked at Shell about using gear oil vs grease. I thought some of us might like to see what he says:

It's true that oil can evaporate (or more commonly, separate from the base and leak away), but in sealed systems (like steering racks) it's less of a problem.  Also, modern 12-hydroxystearate greases can last a long, long time in a sealed system without separation.  Gear oil should work as well, but the seals have to be really good or it will leak out, sometimes so slowly that you don't even notice it.  Gear oils generally use sulfur compounds (like Anglamol) for sliding friction, which can be just as effective as MoS2 (molybdenum disulfide).  After all, they work in differentials.  Either would be fine I'm sure.  Gear oil would certainly be easier to maintain over extended years of use.