I'm changing out the rear end oil to synthetic. Will I need to remove 100% of the dino gear lube. Was at a Freightliner dealer today they told me the syn. gear lubes would curdle when mixed with dino gera lubes. This is Mobile synthetic gear lube.

 

I have changed my front differential lube several times in the past week (another story) Switching back and forth from mineral based to Mobil1 back to mineral and finally Mobil1, and have not experienced the condition you speak of. Mobil1 is lighter in color, and less viscous, but that's about it.

 

Is thge mobile one limited slip ready or will it still need the additive/

 

bkay,

I changed to Mobil 1 in my truck rear-end and didn't add any additive. It seems to be hit or miss as to if you need the additive. Try it without the additive and do the figure 8 manuever, if it chatters get the DC additive.
There isn't any curdling problem that I've ever heard of. ???

 

[quote author=bkay link=board=4;threadid=20668;start=0#msg194006 date=1065554761]
Is thge mobile one limited slip ready or will it still need the additive/
[/quote]

It say it's LS ready, but I had to add 1 1/2 bottle of LS additive before it stopped chattering.

 

[quote author=bkay link=board=4;threadid=20668;start=0#msg193990 date=1065552846]
Was at a Freightliner dealer today they told me the syn. gear lubes would curdle when mixed with dino gera lubes. This is Mobile synthetic gear lube.
[/quote]

They should be compatible, as long as they are both of the same GL rating. Ie GL5

Anyhow, it's always good to get as much of the oil stuff out, but you don't have to be too **** about it.