front and rear Diffs and transfer case oil change questions

i have an 08 sport with rear LSD so i know i need the LS oil for the rear. my issue is that i cant find 75-90 or 80-90 oil that doesn't have the LS additive in it already AND is not synthetic. i have read here that synthetic is not really recommended so i looked for some SAE oil and of it all had Limited Slip marked on the bottle. Is it safe to use the LS oil in the front diff and transfer case? or should i keep looking for non LS oil and get a tube of LS additive for the rear. I went to 3 stores already. Thanks

 

didn't you get scolded in another thread for giving your opinion?

 

I said scolded, it was related to 3rd gen stuff

Now to help OP. what is the issue with synthetic? I think you can use the same fluids but still have to add the additive assuming you need it

 

Thanks guys. I just finished. Did the engine oil, both diffs and transfer case tonight. Took me about an hour and a half or so. Mostly waiting for everything to drain, I only had one drain bucket. I sprayed pb blaster on yesterday and I'm glad I did. The front diff plugs were rusty. The others were fine. Front diff oil was nasty and milky (55k miles) rear wasn't bad (25k) and the transfer case was clear (55k)
Used SAE 80w-90 valvoline limited slip oil and added 4oz of LSD to the rear diff. Test drive tomorrow.

 

i took it out for a ride today and noticed some very fine rhythmic vibrations in the front. doesnt change with speed or RPM, or when on or off the gas, just a little growl that comes and goes in kind of a rhythm...any ideas?

 

Sorry I don't have an answer