2024 Tahoe with the new IRS rear-end G86. I am at 25k and would like to service front and rear differentials and transfer case. Also, I have some down-time right now so it'd be perfect before busy spring and summer comes.
Theres a few videos online of the IRS rear diff being serviced but information is limited. GM calls for 75W-85 and there is an alleged TSB calling for friction modified limited slip additive if you have rear-end chatter when turning left. Front diff also calls for 75W-85.
I am thinking 75W-90 LS for both? Anyone service any of the IRS units yet? My go to, and what I have on hand is Mobil 1 75W-90 LS. So I am assuming if the TSB wants a FM LS additive in it, I'd be just fine with LS fluid.
T-case is easy, Dex VI and be done.
Theres a few videos online of the IRS rear diff being serviced but information is limited. GM calls for 75W-85 and there is an alleged TSB calling for friction modified limited slip additive if you have rear-end chatter when turning left. Front diff also calls for 75W-85.
I am thinking 75W-90 LS for both? Anyone service any of the IRS units yet? My go to, and what I have on hand is Mobil 1 75W-90 LS. So I am assuming if the TSB wants a FM LS additive in it, I'd be just fine with LS fluid.
T-case is easy, Dex VI and be done.
