Swapping from lithium grease (Valvoline red) to non-Lithium (Lucas green)

[LA305]

I recently started greasing my own zerk fittings on my 2005 TJ. I found out from my mechanic that they had been using a pretty generic lithium grease (red) and the first time I did it I used my friends grease gun who had Valvoline high temperature lithium (red) grease which I figured would be fine. Now I want to buy my own gun and want to use Lucas Heavy Duty non-lithium grease (green). I have read that mixing the two can cause them to liquify or cause issues. Anyone know if this is true? Do I have to stick with lithium from now on? Or will I be ok making the switch and I'm overthinking it?

Links below:
Current grease:
https://www.amazon.com/gp/product/B000CQ4DIM/?tag=wranglerorg-20

Want to change to this:
https://www.amazon.com/Lucas-Oil-Ounce-10301-Grease/dp/B000IG20RW

 

[CharlesHS]

When changing the type of grease it is generally recommended to push out the old type of grease. Even though both are NGLI 2, but since one is lithium based and the other is non lithium based; I believe the Valvoline is what is recommended by Chrysler; I would stay with that grease.

 

[Blackjack]

Until all the old grease is purged or you start new you will not see all the benefits with the better grease. Now mixing lithium and polyurea based greases do not cause catastrophic failure like mixing sodium and lithium greases do so for things like ujoints you can just pump the old grease out without fear of failure.

 

[LONGJP2]

Never understood how you can purge all the old grease (or dirt) out. Once the new grease finds an exit (for example - one of the 4 ends of a u-joint), the new grease will just keep moving through that path of least resistance. Why would it try to push anything else out?

 

[SvtLdr]

I have a theory on this one. My tendency is to continue pumping grease into a U-joint past the point of initial purging of the old grease from one of the caps. Pumping more grease in will cause the other caps to begin to weep out old grease, one at a time. If I stick with it long enough I can usually get all 4 caps to purge. Be advised, this take A LOT of grease. Far more than the typical maintenance routine. Could it be that new grease, typically thicker than old grease, will act as a shovel given the chance? And it just takes a TON of grease to eventually push out the old thinner stuff?
That being said, I wouldn't recommend trying this on a rubber boot (ie. track bar, tie rod end, ball joint). I assume you'd trash the boot long before you got much grease to purge out.

 

[jeepins]

One of those things that sometimes it works easy, other times you have to try other means.

 

[Goatman]

Had to purge grease in the military. It takes a HUGE amount to purge effectively. Stick with what's in there. There isn't a significant enough difference in performance on a road vehicle to justify all that work. You could easily grease your Jeep until the end of time with the amount wasted to actually achieve a true purge. And that was when we weren't even changing grease type. Just doin' maintenance.
If you truly believe you need to do this then replace each component and start off with your new stuff. It's about the only way you can really be sure the old grease is gone.

 

[Blackjack]

Never understood how you can purge all the old grease (or dirt) out. Once the new grease finds an exit (for example - one of the 4 ends of a u-joint), the new grease will just keep moving through that path of least resistance. Why would it try to push anything else out?

Greasable ujionts by design are supposed to be greased until they are purging grease from all four caps anything less and they are not properly serviced.