In the past i've been using the Citgo Marine grease, light blue in color. I was in the Merc store the other day and noticed they have two different greases, one for the u-joint/gimbal, the other spline grease. Really? Two different greases? Any good reason for this?

I want to grease these u-joints today and would like to know if I should buy the merc stuff or get a good automotive grease instead?

Thanks.

I have never used the Merc grease and never had any issues. I use the Lucas red tacky grease for everything, including the trailer bearings.

Different applications-different greases. Couplers and bearings, not quite the same. Same as running different motor oil in Alaska from Florida.

That said, any grease is better than no grease.

If you plan to switch, it might be a good idea to clean out the grease that was left. Occasionally you can have compatibility issues with different types of grease.