Whats wrong with Royal Purple? Give me some links for comparrison.

 

IMO, any synthetic > non-synthetic > reclaimed/recycled oils.

So you won't go wrong with any of the synthetics out there.

Me, I use redline MT90 for the trans, and 75-90 for the xfer case. For the diffs, I use Esso/Exxon 80w90 because it's cheap, and I have front diff seepage on one side to deal with again anyways.

 

I used Redline MT-90 for my trans and the difference in shift feel from whatever was already in there was night and day. 100% improvement.

 

redline isnt bad.. for those of you who want links. just go to bitog and look under (atf,gear oil, brake fluid) and do a search. i dont have time to get nit picky and pick out EVERY post. dont have time sorry guys.. this is what i use

amsoil severe gear 75w90 and 75w140 mix half and half to get close to 75w110 mark for diffies

severe gear 75w90 for tcase

amsoil universal atf for tranny (if i get cheap ill use valvolin maxlife)

motor oil---- any syn thats on sale (preferably valvoline synpower bc you can get it buy one get one free about 3 times a year at advance auto)

M1 grease for the drive shaft

 

its not the end of the world dude.. just change it at 30k miles like you are supposed to.. the issue is with synthetics is that most people ASSume that you can run them much longer and in reality its true for some and not true for others. RP is one of them just like M1.. granted it wont lock your gears up if you go 10-15k miles over the 30k change mark but they do shear and will show high bearing wear the higher you go (bc the longer you run the oil the higher the TAN numbers will go and it will become more acidic).. with my amsoil mixture as posted above i feel VERY comfortable at changing them at 50k miles ONLY bc i do a lot of highway driving and very little offroading.

tip, if you use your truck for serious offroading, pulling, hauling, lots of city driving then i would really advise you to change the gear oils frequently 30k miles or less. if yoru truck is a street bitch like mine then you can go longer... just my thoughts

 

MT90 gear oil for tranny post

http://www.bobistheoilguy.com/forums...162605&fpart=1

here is a good one.. granted they arent tacos but gives you a good idea

http://www.bobistheoilguy.com/forums...151285&fpart=1