What happen when grease is used outside it's temp

[Zukinut]

If a grease is used at -5*F and it only rated down to 0*F, does it cake up and cause heat issues or ?

Just trying to learn.

Thanks in advance
Will

 

[The motor guy]

It's just the recommended temp range for the grease, so if you go lower it will most likely just become thicker and not perform as well until it gets some heat buildup from use.

 

[IndyIan]

I imagine the low temp failure mode for grease, is that gets pumped/squished out of the loaded area, but is too thick to have some flow to replace the grease pumped out.
We had one front wheel bearing that would slightly howl in -25-30C for only the first 100m up the driveway. It did that a few times a winter for 10 years and then failed. The other one is still fine.
I assume somehow they got different grease?

 

[Johnny2Bad]

It will almost certainly heat up as whatever it's greasing begins to move, so it's a limited time issue (quite possibly very brief). There may be little or no lubrication initially but that won't last long. Five degrees isn't an issue; 20 or more might be.

Too hot is worse, the lube may "melt" out of the area requiring lubrication in the first place.

 

[buck91]

The operating temp range will primarily be a function of the base oil viscosity.

 

[SuperSalad]

The usable temperature ratings for most greases should be somewhat conservative, so a few degrees over or under should not be a big deal. If the condition do really go beyond the greases capabilities, then the most likely thing to happen is that the grease would not be pliable enough to conform to the surfaces. This might cause an under-lubricated condition, but more than likely it would make whatever is being lubricated hard to turn or move. Once it does start to turn or move though, the grease should become usable rather quickly due to mechanical stress and frictional heat generation.