I aint got one of them. My truck didn't have one when I got it.

 

I put both covers on and waited a hour to final torque them to let the black RTV setup a little. I already bought the fluid, I really wanted Mobile Delvac but I couldn't find it locally. So I went with M1 75W-90. I plan on filling them tomorrow, fingers crossed on no leaks.

 

I checked the manual for service intervals for the light and medium duty.

Schedule A: Lifetime fill
Schedule B: Change rear every 24K, change front every 24K(4x4 only)

 

Yeah i use 80-90 lucas oil front and 80-90 lucas with friction modifier in the rear. But i have a limited slip rear. And yes dirty tranny fluid looking like mud. I know the site. Well mainly cause mine was mud. lol..and thats why a new tranny is now in my truck.. oops.

 

That brings up a good point. I wasn't going to add the modifier in the rear of my LS because the M1 says it is already formulated for a LS. I guess i'll try it without and see if it needs it or not.